Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons

Vladimiacuter Wagner

Nuclear physics institute of CAS 250 68 Řež Czech Republic E_mail wagnerujfcascz

for collaboration ldquoEnergy plus transmutationrdquo

(Russia Belarus Germany Greece Poland Ukraine Czech Republic hellip)

1 Introduction

2 Integral neutron production 21 Used method 22 Overview of lead target data 23 PbU assembly data

3 Spatial distribution of neutron field 41 Comparison between experiment and simulation 42 Possible sources of discrepancies

4 Conclusions and outlooks

NEMEA-4 Workshop October 16-18 2007 Prague Czech Republic

1) Understanding of sources of experimental data uncertainties ndash set of simulations of our set-up using MCNPX code

2) Set of proton experiments with different energies was completed and analyzed first two deuteron experiments were done

3) Systematic comparison of experimental data was done (integral neutron production and its spatial distribution) dependencies on beam energy were analyzed comparison with lead target results

4) Systematic comparison of experimental data with MCNPX simulations

Our main objectives Neutron distribution studies ndash radiation samples

Set-up Lead target diameter 84 cm length 48 cm Natural uranium blanket rods with Al cladding total weight 2064 kg Shielding box polyethylene with 1 mm Cd on the inside side

Energy plus Transmutation (EPT) Setup

Results

Proton systematic

Ep = 07 GeV

Ep = 10 GeV

Ep = 15 GeV

Ep = 20 GeV

Deuteron systematic

Ed = 252 GeV = 126 GeVnucleon

Ed = 16 GeV = 08 GeVnucleon

Experiments

Beam integral 06 ndash 341013 protons or deuterons irradiations - hours

Reactions with thresholds from 6 MeV up to 46 MeV

Spatial distribution of neutron field ( different threshold reactions)

Simulations

MCNPX code ndash Bertini CEM Isabel cascade model INCL4

Used versions MCNPX 26C

The homogenous field of neutrons with energy 1 eV ndash 01 MeV is produced inside container

Example of simulated (MCNPX) neutron spectra inside shielding container with set-up ldquoEnergy + transmutationrdquo(spectrum on the top of U blanket 11 cm from the front)

Container with polyethylene

size 100106111 cm3 weight 950 kg Cd layer at inner walls ndash 1 mm thickness

Reaction 197Au(nγ)198Au ndash only by moderated neutrons from container

Dependence mainly on integral number of neutrons escaping target blanket set-up

Moderation ndash many times scattered neutrons rarr direction information is loosed

Shielding box with polyethylene (the Cd layer is used for thermal neutrons absorption)

Small changes with position

near the center ndash the best situation

We use gold foils

Similar to water bath method in novel variant (K van der Meer NIM B217 (2004) 202)

00

02

04

06

08

10

12

0 10 20 30 40 50

Distance from the target front [cm]

Ex

pe

rim

en

tS

imu

lati

on

00

02

04

06

08

10

12

14

16

18

0 2 4 6 8 10

Foil number

Exp

erim

ent

Sim

ula

tio

ns

0E+00

1E-04

2E-04

3E-04

4E-04

5E-04

6E-04

7E-04

0 10 20 30 40 50Distance from the target front [cm]

Pro

du

ctio

n r

ates

per

pro

ton

an

d f

oil

g

ram

Gold foils - 198Au production inside polyethylene shielding

EPT set-up inside (Ep = 15 GeV) Simple lead target inside (Ep = 0885 GeV)

(determination of ratio between experimental and simulated data for different foils)

Determination of integral number of produced neutrons

Experimental integral neutron number = obtained ratio simulated integral number of neutrons

0

10

20

30

40

50

60

70

80

90

100

0 50 100 150 200

Target thickness [cm]

neut

rons

per

pro

ton

05 GeV

1 GeV

15 GeV

2 GeV

25 GeV

3 GeV

35 GeV

4 GeV

45 GeV

5 GeV

050

100150200250300350400

0 1 2 3 4 5 6Proton energy [GeV]

Ioni

satio

n ra

nge

[cm

]

Neutron production on lead target ndash dependency on target sizes

R = 5 cm

L = 50 cm E = 1 GeV

0

5

10

15

20

25

30

35

0 10 20 30 40 50 60Radius [cm]

neu

tro

ns

per

pro

ton

Saturation ndash for lower beam energy done by ionization stopping - for higher energy done by loose of protons by nuclear reactions

Such experimentaldependenciesA Letourneau et al NIM B170(2000)299(Ep=04 08 12 18 25 GeV)R = 75 cm

(MCNPX simulations)

σTOT (p+Pb) ~ 15 b rarr L = 100 cm rarr 07

0

20

40

60

80

100

120

140

160

0 1 2 3 4 5

Proton energy [GeV]

Ne

utr

on

s p

er

pro

ton R=5 cm L=100 cm

R=50 cm L=100 cm

Systematization of experimental data for lead target

Overview of experimental lead target results K van der Meer NIM B217 (2004) 202(main part of used lead targets have R ~ 5 cm)

Simulations (MCNPX 26C) of integral neutron production on ldquousualrdquo (R = 5cm L = 100 cm) target and target with saturated neutron production

Using MCNPX calculation we recalculated experimental results on the same target size(correction are usually only a few percent exception are only data of Vasilkov with very large target)

Dependency of integral neutron number on beam energy

Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX

SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120

R = 5 cm L = 100 cm

0

10

20

30

40

50

60

0 1 2 3Proton Energy [GeV]

Neu

tro

ns

per

pro

ton

D West E Wood

JS Fraser et al

RG Vasilkov et al 1

RG Vasilkov et al 2

MSZucker et al

our

MA Lone et al

D Hilscher et al

K van der Meer et al

B Lott et al

YuVRyabov et al

A Letourneau et al

MCNPX Simulations

Experimenal data fit

Our simple lead target result

EPT set-up ndash lead plus uranium

U-target (radius=50cm length=150cm)

0

50

100

150

200

250

300

350

0 1 2 3 4 5 6

Proton energy [GeV]

Nu

mb

er o

f n

eutr

on

s escape

capture

total

U-target (radius=optimal length=optimal)

0

50

100

150

200

250

0 1 2 3 4 5 6

Proton energy [MeV]

Num

ber o

f neu

tron

s

escape

Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm

15 GeV

0

10

20

30

40

50

60

70

80

0 50 100 150

target thickness [cm]

neu

tro

ns

per

pro

ton

5

10

15

20

25

30

35

40

45

50

Strong influence of neutron capture

For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons

EPT set-up ndash dependency of integral neutron number on beam energy

Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)

More or less good description of integral neutron production by MCNPX simulation

Beam energynucleon Beam energy per particle

0

10

20

30

40

50

60

70

80

90

0 05 1 15 2 25 3

Beam energy [GeV]

Ne

utr

on

s p

er

pro

ton

Only lead target

EPT experiment -protons

EPT experiment -deuterons

EPT simulation -protons

EPT simulation -deuterons

Pb maximal

Uranium

Pb target -experimental

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV

Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

00

05

10

15

20

25

0 5 10 15Radial distance from target axis [cm]

ex

p

yie

ld

sim

y

ield

20 GeV

15 GeV

10 GeV

07 GeV

High energy neutrons ndash threshold neutron reactions

We see clear dependence of MCNPX description quality on beam energy

Normalized to this foils

197Au(n4n)194Au ETHR=245 MeV

1

15

2

25

3

35

4

45

1 10 100 1000

Neutron energy [MeV]

1 GeV 07 GeV

15 GeV 07 GeV

20 GeV 07 GeV

1E-4

1E-3

1E-2

1E-1

1E+0 1E+1 1E+2 1E+3 1E+4

Neutron Energy [MeV]

Nu

mb

er o

f n

eutr

on

s

07 GeV

1 GeV

15 GeV

2 GeV

Neutron energy spectra for different beam energy

(longitudinal distance radial distance 3 cm)

Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV

Possible source of experiment simulation differences

Conclusions and outlooks

bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments

bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container

bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination

bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target

bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy

bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month

bull Experiments collected nice set of data for systematic benchmark comparison

The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala

Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all

We use activation foils from Au Bi In and Ta

Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)

measurements of cross-sections of (nxn)-reactions (with x up to 9)

The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV

Proposal was sent to EFNUDAT PAC for October meeting

• Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12
• Conclusions and outlooks
• Slide 14

1) Understanding of sources of experimental data uncertainties ndash set of simulations of our set-up using MCNPX code

2) Set of proton experiments with different energies was completed and analyzed first two deuteron experiments were done

3) Systematic comparison of experimental data was done (integral neutron production and its spatial distribution) dependencies on beam energy were analyzed comparison with lead target results

4) Systematic comparison of experimental data with MCNPX simulations

Our main objectives Neutron distribution studies ndash radiation samples

Set-up Lead target diameter 84 cm length 48 cm Natural uranium blanket rods with Al cladding total weight 2064 kg Shielding box polyethylene with 1 mm Cd on the inside side

Energy plus Transmutation (EPT) Setup

Results

Proton systematic

Ep = 07 GeV

Ep = 10 GeV

Ep = 15 GeV

Ep = 20 GeV

Deuteron systematic

Ed = 252 GeV = 126 GeVnucleon

Ed = 16 GeV = 08 GeVnucleon

Experiments

Beam integral 06 ndash 341013 protons or deuterons irradiations - hours

Reactions with thresholds from 6 MeV up to 46 MeV

Spatial distribution of neutron field ( different threshold reactions)

Simulations

MCNPX code ndash Bertini CEM Isabel cascade model INCL4

Used versions MCNPX 26C

The homogenous field of neutrons with energy 1 eV ndash 01 MeV is produced inside container

Example of simulated (MCNPX) neutron spectra inside shielding container with set-up ldquoEnergy + transmutationrdquo(spectrum on the top of U blanket 11 cm from the front)

Container with polyethylene

size 100106111 cm3 weight 950 kg Cd layer at inner walls ndash 1 mm thickness

Reaction 197Au(nγ)198Au ndash only by moderated neutrons from container

Dependence mainly on integral number of neutrons escaping target blanket set-up

Moderation ndash many times scattered neutrons rarr direction information is loosed

Shielding box with polyethylene (the Cd layer is used for thermal neutrons absorption)

Small changes with position

near the center ndash the best situation

We use gold foils

Similar to water bath method in novel variant (K van der Meer NIM B217 (2004) 202)

00

02

04

06

08

10

12

0 10 20 30 40 50

Distance from the target front [cm]

Ex

pe

rim

en

tS

imu

lati

on

00

02

04

06

08

10

12

14

16

18

0 2 4 6 8 10

Foil number

Exp

erim

ent

Sim

ula

tio

ns

0E+00

1E-04

2E-04

3E-04

4E-04

5E-04

6E-04

7E-04

0 10 20 30 40 50Distance from the target front [cm]

Pro

du

ctio

n r

ates

per

pro

ton

an

d f

oil

g

ram

Gold foils - 198Au production inside polyethylene shielding

EPT set-up inside (Ep = 15 GeV) Simple lead target inside (Ep = 0885 GeV)

(determination of ratio between experimental and simulated data for different foils)

Determination of integral number of produced neutrons

Experimental integral neutron number = obtained ratio simulated integral number of neutrons

0

10

20

30

40

50

60

70

80

90

100

0 50 100 150 200

Target thickness [cm]

neut

rons

per

pro

ton

05 GeV

1 GeV

15 GeV

2 GeV

25 GeV

3 GeV

35 GeV

4 GeV

45 GeV

5 GeV

050

100150200250300350400

0 1 2 3 4 5 6Proton energy [GeV]

Ioni

satio

n ra

nge

[cm

]

Neutron production on lead target ndash dependency on target sizes

R = 5 cm

L = 50 cm E = 1 GeV

0

5

10

15

20

25

30

35

0 10 20 30 40 50 60Radius [cm]

neu

tro

ns

per

pro

ton

Saturation ndash for lower beam energy done by ionization stopping - for higher energy done by loose of protons by nuclear reactions

Such experimentaldependenciesA Letourneau et al NIM B170(2000)299(Ep=04 08 12 18 25 GeV)R = 75 cm

(MCNPX simulations)

σTOT (p+Pb) ~ 15 b rarr L = 100 cm rarr 07

0

20

40

60

80

100

120

140

160

0 1 2 3 4 5

Proton energy [GeV]

Ne

utr

on

s p

er

pro

ton R=5 cm L=100 cm

R=50 cm L=100 cm

Systematization of experimental data for lead target

Overview of experimental lead target results K van der Meer NIM B217 (2004) 202(main part of used lead targets have R ~ 5 cm)

Simulations (MCNPX 26C) of integral neutron production on ldquousualrdquo (R = 5cm L = 100 cm) target and target with saturated neutron production

Using MCNPX calculation we recalculated experimental results on the same target size(correction are usually only a few percent exception are only data of Vasilkov with very large target)

Dependency of integral neutron number on beam energy

Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX

SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120

R = 5 cm L = 100 cm

0

10

20

30

40

50

60

0 1 2 3Proton Energy [GeV]

Neu

tro

ns

per

pro

ton

D West E Wood

JS Fraser et al

RG Vasilkov et al 1

RG Vasilkov et al 2

MSZucker et al

our

MA Lone et al

D Hilscher et al

K van der Meer et al

B Lott et al

YuVRyabov et al

A Letourneau et al

MCNPX Simulations

Experimenal data fit

Our simple lead target result

EPT set-up ndash lead plus uranium

U-target (radius=50cm length=150cm)

0

50

100

150

200

250

300

350

0 1 2 3 4 5 6

Proton energy [GeV]

Nu

mb

er o

f n

eutr

on

s escape

capture

total

U-target (radius=optimal length=optimal)

0

50

100

150

200

250

0 1 2 3 4 5 6

Proton energy [MeV]

Num

ber o

f neu

tron

s

escape

Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm

15 GeV

0

10

20

30

40

50

60

70

80

0 50 100 150

target thickness [cm]

neu

tro

ns

per

pro

ton

5

10

15

20

25

30

35

40

45

50

Strong influence of neutron capture

For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons

EPT set-up ndash dependency of integral neutron number on beam energy

Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)

More or less good description of integral neutron production by MCNPX simulation

Beam energynucleon Beam energy per particle

0

10

20

30

40

50

60

70

80

90

0 05 1 15 2 25 3

Beam energy [GeV]

Ne

utr

on

s p

er

pro

ton

Only lead target

EPT experiment -protons

EPT experiment -deuterons

EPT simulation -protons

EPT simulation -deuterons

Pb maximal

Uranium

Pb target -experimental

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV

Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

00

05

10

15

20

25

0 5 10 15Radial distance from target axis [cm]

ex

p

yie

ld

sim

y

ield

20 GeV

15 GeV

10 GeV

07 GeV

High energy neutrons ndash threshold neutron reactions

We see clear dependence of MCNPX description quality on beam energy

Normalized to this foils

197Au(n4n)194Au ETHR=245 MeV

1

15

2

25

3

35

4

45

1 10 100 1000

Neutron energy [MeV]

1 GeV 07 GeV

15 GeV 07 GeV

20 GeV 07 GeV

1E-4

1E-3

1E-2

1E-1

1E+0 1E+1 1E+2 1E+3 1E+4

Neutron Energy [MeV]

Nu

mb

er o

f n

eutr

on

s

07 GeV

1 GeV

15 GeV

2 GeV

Neutron energy spectra for different beam energy

(longitudinal distance radial distance 3 cm)

Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV

Possible source of experiment simulation differences

Conclusions and outlooks

bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments

bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container

bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination

bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target

bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy

bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month

bull Experiments collected nice set of data for systematic benchmark comparison

The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala

Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all

We use activation foils from Au Bi In and Ta

Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)

measurements of cross-sections of (nxn)-reactions (with x up to 9)

The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV

Proposal was sent to EFNUDAT PAC for October meeting

• Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12
• Conclusions and outlooks
• Slide 14

Proton systematic

Ep = 07 GeV

Ep = 10 GeV

Ep = 15 GeV

Ep = 20 GeV

Deuteron systematic

Ed = 252 GeV = 126 GeVnucleon

Ed = 16 GeV = 08 GeVnucleon

Experiments

Beam integral 06 ndash 341013 protons or deuterons irradiations - hours

Reactions with thresholds from 6 MeV up to 46 MeV

Spatial distribution of neutron field ( different threshold reactions)

Simulations

MCNPX code ndash Bertini CEM Isabel cascade model INCL4

Used versions MCNPX 26C

The homogenous field of neutrons with energy 1 eV ndash 01 MeV is produced inside container

Example of simulated (MCNPX) neutron spectra inside shielding container with set-up ldquoEnergy + transmutationrdquo(spectrum on the top of U blanket 11 cm from the front)

Container with polyethylene

size 100106111 cm3 weight 950 kg Cd layer at inner walls ndash 1 mm thickness

Reaction 197Au(nγ)198Au ndash only by moderated neutrons from container

Dependence mainly on integral number of neutrons escaping target blanket set-up

Moderation ndash many times scattered neutrons rarr direction information is loosed

Shielding box with polyethylene (the Cd layer is used for thermal neutrons absorption)

Small changes with position

near the center ndash the best situation

We use gold foils

Similar to water bath method in novel variant (K van der Meer NIM B217 (2004) 202)

00

02

04

06

08

10

12

0 10 20 30 40 50

Distance from the target front [cm]

Ex

pe

rim

en

tS

imu

lati

on

00

02

04

06

08

10

12

14

16

18

0 2 4 6 8 10

Foil number

Exp

erim

ent

Sim

ula

tio

ns

0E+00

1E-04

2E-04

3E-04

4E-04

5E-04

6E-04

7E-04

0 10 20 30 40 50Distance from the target front [cm]

Pro

du

ctio

n r

ates

per

pro

ton

an

d f

oil

g

ram

Gold foils - 198Au production inside polyethylene shielding

EPT set-up inside (Ep = 15 GeV) Simple lead target inside (Ep = 0885 GeV)

(determination of ratio between experimental and simulated data for different foils)

Determination of integral number of produced neutrons

Experimental integral neutron number = obtained ratio simulated integral number of neutrons

0

10

20

30

40

50

60

70

80

90

100

0 50 100 150 200

Target thickness [cm]

neut

rons

per

pro

ton

05 GeV

1 GeV

15 GeV

2 GeV

25 GeV

3 GeV

35 GeV

4 GeV

45 GeV

5 GeV

050

100150200250300350400

0 1 2 3 4 5 6Proton energy [GeV]

Ioni

satio

n ra

nge

[cm

]

Neutron production on lead target ndash dependency on target sizes

R = 5 cm

L = 50 cm E = 1 GeV

0

5

10

15

20

25

30

35

0 10 20 30 40 50 60Radius [cm]

neu

tro

ns

per

pro

ton

Saturation ndash for lower beam energy done by ionization stopping - for higher energy done by loose of protons by nuclear reactions

Such experimentaldependenciesA Letourneau et al NIM B170(2000)299(Ep=04 08 12 18 25 GeV)R = 75 cm

(MCNPX simulations)

σTOT (p+Pb) ~ 15 b rarr L = 100 cm rarr 07

0

20

40

60

80

100

120

140

160

0 1 2 3 4 5

Proton energy [GeV]

Ne

utr

on

s p

er

pro

ton R=5 cm L=100 cm

R=50 cm L=100 cm

Systematization of experimental data for lead target

Overview of experimental lead target results K van der Meer NIM B217 (2004) 202(main part of used lead targets have R ~ 5 cm)

Simulations (MCNPX 26C) of integral neutron production on ldquousualrdquo (R = 5cm L = 100 cm) target and target with saturated neutron production

Using MCNPX calculation we recalculated experimental results on the same target size(correction are usually only a few percent exception are only data of Vasilkov with very large target)

Dependency of integral neutron number on beam energy

Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX

SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120

R = 5 cm L = 100 cm

0

10

20

30

40

50

60

0 1 2 3Proton Energy [GeV]

Neu

tro

ns

per

pro

ton

D West E Wood

JS Fraser et al

RG Vasilkov et al 1

RG Vasilkov et al 2

MSZucker et al

our

MA Lone et al

D Hilscher et al

K van der Meer et al

B Lott et al

YuVRyabov et al

A Letourneau et al

MCNPX Simulations

Experimenal data fit

Our simple lead target result

EPT set-up ndash lead plus uranium

U-target (radius=50cm length=150cm)

0

50

100

150

200

250

300

350

0 1 2 3 4 5 6

Proton energy [GeV]

Nu

mb

er o

f n

eutr

on

s escape

capture

total

U-target (radius=optimal length=optimal)

0

50

100

150

200

250

0 1 2 3 4 5 6

Proton energy [MeV]

Num

ber o

f neu

tron

s

escape

Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm

15 GeV

0

10

20

30

40

50

60

70

80

0 50 100 150

target thickness [cm]

neu

tro

ns

per

pro

ton

5

10

15

20

25

30

35

40

45

50

Strong influence of neutron capture

For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons

EPT set-up ndash dependency of integral neutron number on beam energy

Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)

More or less good description of integral neutron production by MCNPX simulation

Beam energynucleon Beam energy per particle

0

10

20

30

40

50

60

70

80

90

0 05 1 15 2 25 3

Beam energy [GeV]

Ne

utr

on

s p

er

pro

ton

Only lead target

EPT experiment -protons

EPT experiment -deuterons

EPT simulation -protons

EPT simulation -deuterons

Pb maximal

Uranium

Pb target -experimental

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV

Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

00

05

10

15

20

25

0 5 10 15Radial distance from target axis [cm]

ex

p

yie

ld

sim

y

ield

20 GeV

15 GeV

10 GeV

07 GeV

High energy neutrons ndash threshold neutron reactions

We see clear dependence of MCNPX description quality on beam energy

Normalized to this foils

197Au(n4n)194Au ETHR=245 MeV

1

15

2

25

3

35

4

45

1 10 100 1000

Neutron energy [MeV]

1 GeV 07 GeV

15 GeV 07 GeV

20 GeV 07 GeV

1E-4

1E-3

1E-2

1E-1

1E+0 1E+1 1E+2 1E+3 1E+4

Neutron Energy [MeV]

Nu

mb

er o

f n

eutr

on

s

07 GeV

1 GeV

15 GeV

2 GeV

Neutron energy spectra for different beam energy

(longitudinal distance radial distance 3 cm)

Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV

Possible source of experiment simulation differences

Conclusions and outlooks

bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments

bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container

bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination

bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target

bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy

bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month

bull Experiments collected nice set of data for systematic benchmark comparison

The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala

Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all

We use activation foils from Au Bi In and Ta

Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)

measurements of cross-sections of (nxn)-reactions (with x up to 9)

The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV

Proposal was sent to EFNUDAT PAC for October meeting

• Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12
• Conclusions and outlooks
• Slide 14

The homogenous field of neutrons with energy 1 eV ndash 01 MeV is produced inside container

Example of simulated (MCNPX) neutron spectra inside shielding container with set-up ldquoEnergy + transmutationrdquo(spectrum on the top of U blanket 11 cm from the front)

Container with polyethylene

size 100106111 cm3 weight 950 kg Cd layer at inner walls ndash 1 mm thickness

Reaction 197Au(nγ)198Au ndash only by moderated neutrons from container

Dependence mainly on integral number of neutrons escaping target blanket set-up

Moderation ndash many times scattered neutrons rarr direction information is loosed

Shielding box with polyethylene (the Cd layer is used for thermal neutrons absorption)

Small changes with position

near the center ndash the best situation

We use gold foils

Similar to water bath method in novel variant (K van der Meer NIM B217 (2004) 202)

00

02

04

06

08

10

12

0 10 20 30 40 50

Distance from the target front [cm]

Ex

pe

rim

en

tS

imu

lati

on

00

02

04

06

08

10

12

14

16

18

0 2 4 6 8 10

Foil number

Exp

erim

ent

Sim

ula

tio

ns

0E+00

1E-04

2E-04

3E-04

4E-04

5E-04

6E-04

7E-04

0 10 20 30 40 50Distance from the target front [cm]

Pro

du

ctio

n r

ates

per

pro

ton

an

d f

oil

g

ram

Gold foils - 198Au production inside polyethylene shielding

EPT set-up inside (Ep = 15 GeV) Simple lead target inside (Ep = 0885 GeV)

(determination of ratio between experimental and simulated data for different foils)

Determination of integral number of produced neutrons

Experimental integral neutron number = obtained ratio simulated integral number of neutrons

0

10

20

30

40

50

60

70

80

90

100

0 50 100 150 200

Target thickness [cm]

neut

rons

per

pro

ton

05 GeV

1 GeV

15 GeV

2 GeV

25 GeV

3 GeV

35 GeV

4 GeV

45 GeV

5 GeV

050

100150200250300350400

0 1 2 3 4 5 6Proton energy [GeV]

Ioni

satio

n ra

nge

[cm

]

Neutron production on lead target ndash dependency on target sizes

R = 5 cm

L = 50 cm E = 1 GeV

0

5

10

15

20

25

30

35

0 10 20 30 40 50 60Radius [cm]

neu

tro

ns

per

pro

ton

Saturation ndash for lower beam energy done by ionization stopping - for higher energy done by loose of protons by nuclear reactions

Such experimentaldependenciesA Letourneau et al NIM B170(2000)299(Ep=04 08 12 18 25 GeV)R = 75 cm

(MCNPX simulations)

σTOT (p+Pb) ~ 15 b rarr L = 100 cm rarr 07

0

20

40

60

80

100

120

140

160

0 1 2 3 4 5

Proton energy [GeV]

Ne

utr

on

s p

er

pro

ton R=5 cm L=100 cm

R=50 cm L=100 cm

Systematization of experimental data for lead target

Overview of experimental lead target results K van der Meer NIM B217 (2004) 202(main part of used lead targets have R ~ 5 cm)

Simulations (MCNPX 26C) of integral neutron production on ldquousualrdquo (R = 5cm L = 100 cm) target and target with saturated neutron production

Using MCNPX calculation we recalculated experimental results on the same target size(correction are usually only a few percent exception are only data of Vasilkov with very large target)

Dependency of integral neutron number on beam energy

Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX

SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120

R = 5 cm L = 100 cm

0

10

20

30

40

50

60

0 1 2 3Proton Energy [GeV]

Neu

tro

ns

per

pro

ton

D West E Wood

JS Fraser et al

RG Vasilkov et al 1

RG Vasilkov et al 2

MSZucker et al

our

MA Lone et al

D Hilscher et al

K van der Meer et al

B Lott et al

YuVRyabov et al

A Letourneau et al

MCNPX Simulations

Experimenal data fit

Our simple lead target result

EPT set-up ndash lead plus uranium

U-target (radius=50cm length=150cm)

0

50

100

150

200

250

300

350

0 1 2 3 4 5 6

Proton energy [GeV]

Nu

mb

er o

f n

eutr

on

s escape

capture

total

U-target (radius=optimal length=optimal)

0

50

100

150

200

250

0 1 2 3 4 5 6

Proton energy [MeV]

Num

ber o

f neu

tron

s

escape

Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm

15 GeV

0

10

20

30

40

50

60

70

80

0 50 100 150

target thickness [cm]

neu

tro

ns

per

pro

ton

5

10

15

20

25

30

35

40

45

50

Strong influence of neutron capture

For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons

EPT set-up ndash dependency of integral neutron number on beam energy

Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)

More or less good description of integral neutron production by MCNPX simulation

Beam energynucleon Beam energy per particle

0

10

20

30

40

50

60

70

80

90

0 05 1 15 2 25 3

Beam energy [GeV]

Ne

utr

on

s p

er

pro

ton

Only lead target

EPT experiment -protons

EPT experiment -deuterons

EPT simulation -protons

EPT simulation -deuterons

Pb maximal

Uranium

Pb target -experimental

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV

Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

00

05

10

15

20

25

0 5 10 15Radial distance from target axis [cm]

ex

p

yie

ld

sim

y

ield

20 GeV

15 GeV

10 GeV

07 GeV

High energy neutrons ndash threshold neutron reactions

We see clear dependence of MCNPX description quality on beam energy

Normalized to this foils

197Au(n4n)194Au ETHR=245 MeV

1

15

2

25

3

35

4

45

1 10 100 1000

Neutron energy [MeV]

1 GeV 07 GeV

15 GeV 07 GeV

20 GeV 07 GeV

1E-4

1E-3

1E-2

1E-1

1E+0 1E+1 1E+2 1E+3 1E+4

Neutron Energy [MeV]

Nu

mb

er o

f n

eutr

on

s

07 GeV

1 GeV

15 GeV

2 GeV

Neutron energy spectra for different beam energy

(longitudinal distance radial distance 3 cm)

Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV

Possible source of experiment simulation differences

Conclusions and outlooks

bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments

bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container

bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination

bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target

bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy

bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month

bull Experiments collected nice set of data for systematic benchmark comparison

The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala

Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all

We use activation foils from Au Bi In and Ta

Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)

measurements of cross-sections of (nxn)-reactions (with x up to 9)

The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV

Proposal was sent to EFNUDAT PAC for October meeting

• Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12
• Conclusions and outlooks
• Slide 14

Small changes with position

near the center ndash the best situation

We use gold foils

Similar to water bath method in novel variant (K van der Meer NIM B217 (2004) 202)

00

02

04

06

08

10

12

0 10 20 30 40 50

Distance from the target front [cm]

Ex

pe

rim

en

tS

imu

lati

on

00

02

04

06

08

10

12

14

16

18

0 2 4 6 8 10

Foil number

Exp

erim

ent

Sim

ula

tio

ns

0E+00

1E-04

2E-04

3E-04

4E-04

5E-04

6E-04

7E-04

0 10 20 30 40 50Distance from the target front [cm]

Pro

du

ctio

n r

ates

per

pro

ton

an

d f

oil

g

ram

Gold foils - 198Au production inside polyethylene shielding

EPT set-up inside (Ep = 15 GeV) Simple lead target inside (Ep = 0885 GeV)

(determination of ratio between experimental and simulated data for different foils)

Determination of integral number of produced neutrons

Experimental integral neutron number = obtained ratio simulated integral number of neutrons

0

10

20

30

40

50

60

70

80

90

100

0 50 100 150 200

Target thickness [cm]

neut

rons

per

pro

ton

05 GeV

1 GeV

15 GeV

2 GeV

25 GeV

3 GeV

35 GeV

4 GeV

45 GeV

5 GeV

050

100150200250300350400

0 1 2 3 4 5 6Proton energy [GeV]

Ioni

satio

n ra

nge

[cm

]

Neutron production on lead target ndash dependency on target sizes

R = 5 cm

L = 50 cm E = 1 GeV

0

5

10

15

20

25

30

35

0 10 20 30 40 50 60Radius [cm]

neu

tro

ns

per

pro

ton

Saturation ndash for lower beam energy done by ionization stopping - for higher energy done by loose of protons by nuclear reactions

Such experimentaldependenciesA Letourneau et al NIM B170(2000)299(Ep=04 08 12 18 25 GeV)R = 75 cm

(MCNPX simulations)

σTOT (p+Pb) ~ 15 b rarr L = 100 cm rarr 07

0

20

40

60

80

100

120

140

160

0 1 2 3 4 5

Proton energy [GeV]

Ne

utr

on

s p

er

pro

ton R=5 cm L=100 cm

R=50 cm L=100 cm

Systematization of experimental data for lead target

Overview of experimental lead target results K van der Meer NIM B217 (2004) 202(main part of used lead targets have R ~ 5 cm)

Simulations (MCNPX 26C) of integral neutron production on ldquousualrdquo (R = 5cm L = 100 cm) target and target with saturated neutron production

Using MCNPX calculation we recalculated experimental results on the same target size(correction are usually only a few percent exception are only data of Vasilkov with very large target)

Dependency of integral neutron number on beam energy

Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX

SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120

R = 5 cm L = 100 cm

0

10

20

30

40

50

60

0 1 2 3Proton Energy [GeV]

Neu

tro

ns

per

pro

ton

D West E Wood

JS Fraser et al

RG Vasilkov et al 1

RG Vasilkov et al 2

MSZucker et al

our

MA Lone et al

D Hilscher et al

K van der Meer et al

B Lott et al

YuVRyabov et al

A Letourneau et al

MCNPX Simulations

Experimenal data fit

Our simple lead target result

EPT set-up ndash lead plus uranium

U-target (radius=50cm length=150cm)

0

50

100

150

200

250

300

350

0 1 2 3 4 5 6

Proton energy [GeV]

Nu

mb

er o

f n

eutr

on

s escape

capture

total

U-target (radius=optimal length=optimal)

0

50

100

150

200

250

0 1 2 3 4 5 6

Proton energy [MeV]

Num

ber o

f neu

tron

s

escape

Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm

15 GeV

0

10

20

30

40

50

60

70

80

0 50 100 150

target thickness [cm]

neu

tro

ns

per

pro

ton

5

10

15

20

25

30

35

40

45

50

Strong influence of neutron capture

For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons

EPT set-up ndash dependency of integral neutron number on beam energy

Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)

More or less good description of integral neutron production by MCNPX simulation

Beam energynucleon Beam energy per particle

0

10

20

30

40

50

60

70

80

90

0 05 1 15 2 25 3

Beam energy [GeV]

Ne

utr

on

s p

er

pro

ton

Only lead target

EPT experiment -protons

EPT experiment -deuterons

EPT simulation -protons

EPT simulation -deuterons

Pb maximal

Uranium

Pb target -experimental

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV

Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

00

05

10

15

20

25

0 5 10 15Radial distance from target axis [cm]

ex

p

yie

ld

sim

y

ield

20 GeV

15 GeV

10 GeV

07 GeV

High energy neutrons ndash threshold neutron reactions

We see clear dependence of MCNPX description quality on beam energy

Normalized to this foils

197Au(n4n)194Au ETHR=245 MeV

1

15

2

25

3

35

4

45

1 10 100 1000

Neutron energy [MeV]

1 GeV 07 GeV

15 GeV 07 GeV

20 GeV 07 GeV

1E-4

1E-3

1E-2

1E-1

1E+0 1E+1 1E+2 1E+3 1E+4

Neutron Energy [MeV]

Nu

mb

er o

f n

eutr

on

s

07 GeV

1 GeV

15 GeV

2 GeV

Neutron energy spectra for different beam energy

(longitudinal distance radial distance 3 cm)

Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV

Possible source of experiment simulation differences

Conclusions and outlooks

bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments

bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container

bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination

bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target

bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy

bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month

bull Experiments collected nice set of data for systematic benchmark comparison

The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala

Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all

We use activation foils from Au Bi In and Ta

Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)

measurements of cross-sections of (nxn)-reactions (with x up to 9)

The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV

Proposal was sent to EFNUDAT PAC for October meeting

• Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12
• Conclusions and outlooks
• Slide 14

0

10

20

30

40

50

60

70

80

90

100

0 50 100 150 200

Target thickness [cm]

neut

rons

per

pro

ton

05 GeV

1 GeV

15 GeV

2 GeV

25 GeV

3 GeV

35 GeV

4 GeV

45 GeV

5 GeV

050

100150200250300350400

0 1 2 3 4 5 6Proton energy [GeV]

Ioni

satio

n ra

nge

[cm

]

Neutron production on lead target ndash dependency on target sizes

R = 5 cm

L = 50 cm E = 1 GeV

0

5

10

15

20

25

30

35

0 10 20 30 40 50 60Radius [cm]

neu

tro

ns

per

pro

ton

Saturation ndash for lower beam energy done by ionization stopping - for higher energy done by loose of protons by nuclear reactions

Such experimentaldependenciesA Letourneau et al NIM B170(2000)299(Ep=04 08 12 18 25 GeV)R = 75 cm

(MCNPX simulations)

σTOT (p+Pb) ~ 15 b rarr L = 100 cm rarr 07

0

20

40

60

80

100

120

140

160

0 1 2 3 4 5

Proton energy [GeV]

Ne

utr

on

s p

er

pro

ton R=5 cm L=100 cm

R=50 cm L=100 cm

Systematization of experimental data for lead target

Overview of experimental lead target results K van der Meer NIM B217 (2004) 202(main part of used lead targets have R ~ 5 cm)

Simulations (MCNPX 26C) of integral neutron production on ldquousualrdquo (R = 5cm L = 100 cm) target and target with saturated neutron production

Using MCNPX calculation we recalculated experimental results on the same target size(correction are usually only a few percent exception are only data of Vasilkov with very large target)

Dependency of integral neutron number on beam energy

Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX

SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120

R = 5 cm L = 100 cm

0

10

20

30

40

50

60

0 1 2 3Proton Energy [GeV]

Neu

tro

ns

per

pro

ton

D West E Wood

JS Fraser et al

RG Vasilkov et al 1

RG Vasilkov et al 2

MSZucker et al

our

MA Lone et al

D Hilscher et al

K van der Meer et al

B Lott et al

YuVRyabov et al

A Letourneau et al

MCNPX Simulations

Experimenal data fit

Our simple lead target result

EPT set-up ndash lead plus uranium

U-target (radius=50cm length=150cm)

0

50

100

150

200

250

300

350

0 1 2 3 4 5 6

Proton energy [GeV]

Nu

mb

er o

f n

eutr

on

s escape

capture

total

U-target (radius=optimal length=optimal)

0

50

100

150

200

250

0 1 2 3 4 5 6

Proton energy [MeV]

Num

ber o

f neu

tron

s

escape

Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm

15 GeV

0

10

20

30

40

50

60

70

80

0 50 100 150

target thickness [cm]

neu

tro

ns

per

pro

ton

5

10

15

20

25

30

35

40

45

50

Strong influence of neutron capture

For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons

EPT set-up ndash dependency of integral neutron number on beam energy

Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)

More or less good description of integral neutron production by MCNPX simulation

Beam energynucleon Beam energy per particle

0

10

20

30

40

50

60

70

80

90

0 05 1 15 2 25 3

Beam energy [GeV]

Ne

utr

on

s p

er

pro

ton

Only lead target

EPT experiment -protons

EPT experiment -deuterons

EPT simulation -protons

EPT simulation -deuterons

Pb maximal

Uranium

Pb target -experimental

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV

Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

00

05

10

15

20

25

0 5 10 15Radial distance from target axis [cm]

ex

p

yie

ld

sim

y

ield

20 GeV

15 GeV

10 GeV

07 GeV

High energy neutrons ndash threshold neutron reactions

We see clear dependence of MCNPX description quality on beam energy

Normalized to this foils

197Au(n4n)194Au ETHR=245 MeV

1

15

2

25

3

35

4

45

1 10 100 1000

Neutron energy [MeV]

1 GeV 07 GeV

15 GeV 07 GeV

20 GeV 07 GeV

1E-4

1E-3

1E-2

1E-1

1E+0 1E+1 1E+2 1E+3 1E+4

Neutron Energy [MeV]

Nu

mb

er o

f n

eutr

on

s

07 GeV

1 GeV

15 GeV

2 GeV

Neutron energy spectra for different beam energy

(longitudinal distance radial distance 3 cm)

Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV

Possible source of experiment simulation differences

Conclusions and outlooks

bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments

bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container

bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination

bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target

bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy

bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month

bull Experiments collected nice set of data for systematic benchmark comparison

The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala

Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all

We use activation foils from Au Bi In and Ta

Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)

measurements of cross-sections of (nxn)-reactions (with x up to 9)

The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV

Proposal was sent to EFNUDAT PAC for October meeting

• Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12
• Conclusions and outlooks
• Slide 14

0

20

40

60

80

100

120

140

160

0 1 2 3 4 5

Proton energy [GeV]

Ne

utr

on

s p

er

pro

ton R=5 cm L=100 cm

R=50 cm L=100 cm

Systematization of experimental data for lead target

Overview of experimental lead target results K van der Meer NIM B217 (2004) 202(main part of used lead targets have R ~ 5 cm)

Simulations (MCNPX 26C) of integral neutron production on ldquousualrdquo (R = 5cm L = 100 cm) target and target with saturated neutron production

Using MCNPX calculation we recalculated experimental results on the same target size(correction are usually only a few percent exception are only data of Vasilkov with very large target)

Dependency of integral neutron number on beam energy

Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX

SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120

R = 5 cm L = 100 cm

0

10

20

30

40

50

60

0 1 2 3Proton Energy [GeV]

Neu

tro

ns

per

pro

ton

D West E Wood

JS Fraser et al

RG Vasilkov et al 1

RG Vasilkov et al 2

MSZucker et al

our

MA Lone et al

D Hilscher et al

K van der Meer et al

B Lott et al

YuVRyabov et al

A Letourneau et al

MCNPX Simulations

Experimenal data fit

Our simple lead target result

EPT set-up ndash lead plus uranium

U-target (radius=50cm length=150cm)

0

50

100

150

200

250

300

350

0 1 2 3 4 5 6

Proton energy [GeV]

Nu

mb

er o

f n

eutr

on

s escape

capture

total

U-target (radius=optimal length=optimal)

0

50

100

150

200

250

0 1 2 3 4 5 6

Proton energy [MeV]

Num

ber o

f neu

tron

s

escape

Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm

15 GeV

0

10

20

30

40

50

60

70

80

0 50 100 150

target thickness [cm]

neu

tro

ns

per

pro

ton

5

10

15

20

25

30

35

40

45

50

Strong influence of neutron capture

For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons

EPT set-up ndash dependency of integral neutron number on beam energy

Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)

More or less good description of integral neutron production by MCNPX simulation

Beam energynucleon Beam energy per particle

0

10

20

30

40

50

60

70

80

90

0 05 1 15 2 25 3

Beam energy [GeV]

Ne

utr

on

s p

er

pro

ton

Only lead target

EPT experiment -protons

EPT experiment -deuterons

EPT simulation -protons

EPT simulation -deuterons

Pb maximal

Uranium

Pb target -experimental

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV

Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

00

05

10

15

20

25

0 5 10 15Radial distance from target axis [cm]

ex

p

yie

ld

sim

y

ield

20 GeV

15 GeV

10 GeV

07 GeV

High energy neutrons ndash threshold neutron reactions

We see clear dependence of MCNPX description quality on beam energy

Normalized to this foils

197Au(n4n)194Au ETHR=245 MeV

1

15

2

25

3

35

4

45

1 10 100 1000

Neutron energy [MeV]

1 GeV 07 GeV

15 GeV 07 GeV

20 GeV 07 GeV

1E-4

1E-3

1E-2

1E-1

1E+0 1E+1 1E+2 1E+3 1E+4

Neutron Energy [MeV]

Nu

mb

er o

f n

eutr

on

s

07 GeV

1 GeV

15 GeV

2 GeV

Neutron energy spectra for different beam energy

(longitudinal distance radial distance 3 cm)

Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV

Possible source of experiment simulation differences

Conclusions and outlooks

bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments

bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container

bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination

bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target

bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy

bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month

bull Experiments collected nice set of data for systematic benchmark comparison

The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala

Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all

We use activation foils from Au Bi In and Ta

Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)

measurements of cross-sections of (nxn)-reactions (with x up to 9)

The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV

Proposal was sent to EFNUDAT PAC for October meeting

• Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12
• Conclusions and outlooks
• Slide 14

Dependency of integral neutron number on beam energy

Beam energy lt 1 GeV good description using MCNPX gt 1 GeV overestimation using MCNPX

SimulationExperiment 05 GeV ndash 101 10 GeV ndash 113 20 GeV ndash 115 30 GeV - 120

R = 5 cm L = 100 cm

0

10

20

30

40

50

60

0 1 2 3Proton Energy [GeV]

Neu

tro

ns

per

pro

ton

D West E Wood

JS Fraser et al

RG Vasilkov et al 1

RG Vasilkov et al 2

MSZucker et al

our

MA Lone et al

D Hilscher et al

K van der Meer et al

B Lott et al

YuVRyabov et al

A Letourneau et al

MCNPX Simulations

Experimenal data fit

Our simple lead target result

EPT set-up ndash lead plus uranium

U-target (radius=50cm length=150cm)

0

50

100

150

200

250

300

350

0 1 2 3 4 5 6

Proton energy [GeV]

Nu

mb

er o

f n

eutr

on

s escape

capture

total

U-target (radius=optimal length=optimal)

0

50

100

150

200

250

0 1 2 3 4 5 6

Proton energy [MeV]

Num

ber o

f neu

tron

s

escape

Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm

15 GeV

0

10

20

30

40

50

60

70

80

0 50 100 150

target thickness [cm]

neu

tro

ns

per

pro

ton

5

10

15

20

25

30

35

40

45

50

Strong influence of neutron capture

For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons

EPT set-up ndash dependency of integral neutron number on beam energy

Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)

More or less good description of integral neutron production by MCNPX simulation

Beam energynucleon Beam energy per particle

0

10

20

30

40

50

60

70

80

90

0 05 1 15 2 25 3

Beam energy [GeV]

Ne

utr

on

s p

er

pro

ton

Only lead target

EPT experiment -protons

EPT experiment -deuterons

EPT simulation -protons

EPT simulation -deuterons

Pb maximal

Uranium

Pb target -experimental

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV

Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

00

05

10

15

20

25

0 5 10 15Radial distance from target axis [cm]

ex

p

yie

ld

sim

y

ield

20 GeV

15 GeV

10 GeV

07 GeV

High energy neutrons ndash threshold neutron reactions

We see clear dependence of MCNPX description quality on beam energy

Normalized to this foils

197Au(n4n)194Au ETHR=245 MeV

1

15

2

25

3

35

4

45

1 10 100 1000

Neutron energy [MeV]

1 GeV 07 GeV

15 GeV 07 GeV

20 GeV 07 GeV

1E-4

1E-3

1E-2

1E-1

1E+0 1E+1 1E+2 1E+3 1E+4

Neutron Energy [MeV]

Nu

mb

er o

f n

eutr

on

s

07 GeV

1 GeV

15 GeV

2 GeV

Neutron energy spectra for different beam energy

(longitudinal distance radial distance 3 cm)

Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV

Possible source of experiment simulation differences

Conclusions and outlooks

bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments

bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container

bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination

bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target

bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy

bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month

bull Experiments collected nice set of data for systematic benchmark comparison

The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala

Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all

We use activation foils from Au Bi In and Ta

Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)

measurements of cross-sections of (nxn)-reactions (with x up to 9)

The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV

Proposal was sent to EFNUDAT PAC for October meeting

• Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12
• Conclusions and outlooks
• Slide 14

EPT set-up ndash lead plus uranium

U-target (radius=50cm length=150cm)

0

50

100

150

200

250

300

350

0 1 2 3 4 5 6

Proton energy [GeV]

Nu

mb

er o

f n

eutr

on

s escape

capture

total

U-target (radius=optimal length=optimal)

0

50

100

150

200

250

0 1 2 3 4 5 6

Proton energy [MeV]

Num

ber o

f neu

tron

s

escape

Maximal number of escaped neutrons from target for R = 20 cm L = 150 cm

15 GeV

0

10

20

30

40

50

60

70

80

0 50 100 150

target thickness [cm]

neu

tro

ns

per

pro

ton

5

10

15

20

25

30

35

40

45

50

Strong influence of neutron capture

For some diameter maximal number of escaping neutrons for larger target decreasing number of escaping neutrons

EPT set-up ndash dependency of integral neutron number on beam energy

Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)

More or less good description of integral neutron production by MCNPX simulation

Beam energynucleon Beam energy per particle

0

10

20

30

40

50

60

70

80

90

0 05 1 15 2 25 3

Beam energy [GeV]

Ne

utr

on

s p

er

pro

ton

Only lead target

EPT experiment -protons

EPT experiment -deuterons

EPT simulation -protons

EPT simulation -deuterons

Pb maximal

Uranium

Pb target -experimental

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV

Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

00

05

10

15

20

25

0 5 10 15Radial distance from target axis [cm]

ex

p

yie

ld

sim

y

ield

20 GeV

15 GeV

10 GeV

07 GeV

High energy neutrons ndash threshold neutron reactions

We see clear dependence of MCNPX description quality on beam energy

Normalized to this foils

197Au(n4n)194Au ETHR=245 MeV

1

15

2

25

3

35

4

45

1 10 100 1000

Neutron energy [MeV]

1 GeV 07 GeV

15 GeV 07 GeV

20 GeV 07 GeV

1E-4

1E-3

1E-2

1E-1

1E+0 1E+1 1E+2 1E+3 1E+4

Neutron Energy [MeV]

Nu

mb

er o

f n

eutr

on

s

07 GeV

1 GeV

15 GeV

2 GeV

Neutron energy spectra for different beam energy

(longitudinal distance radial distance 3 cm)

Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV

Possible source of experiment simulation differences

Conclusions and outlooks

bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments

bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container

bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination

bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target

bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy

bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month

bull Experiments collected nice set of data for systematic benchmark comparison

The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala

Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all

We use activation foils from Au Bi In and Ta

Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)

measurements of cross-sections of (nxn)-reactions (with x up to 9)

The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV

Proposal was sent to EFNUDAT PAC for October meeting

• Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12
• Conclusions and outlooks
• Slide 14

EPT set-up ndash dependency of integral neutron number on beam energy

Clearly visible is saturation of number of neutrons per energy unit near 1 GeV proton energy (energy per nucleon)

More or less good description of integral neutron production by MCNPX simulation

Beam energynucleon Beam energy per particle

0

10

20

30

40

50

60

70

80

90

0 05 1 15 2 25 3

Beam energy [GeV]

Ne

utr

on

s p

er

pro

ton

Only lead target

EPT experiment -protons

EPT experiment -deuterons

EPT simulation -protons

EPT simulation -deuterons

Pb maximal

Uranium

Pb target -experimental

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV

Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

0

10

20

30

40

50

60

0 1 2 3

Beam energy [GeV]

neu

tro

ns

per

1 G

eV Protons - experiment

Protons - simulation

Deuterons - experiment

Deuterons - simulation

00

05

10

15

20

25

0 5 10 15Radial distance from target axis [cm]

ex

p

yie

ld

sim

y

ield

20 GeV

15 GeV

10 GeV

07 GeV

High energy neutrons ndash threshold neutron reactions

We see clear dependence of MCNPX description quality on beam energy

Normalized to this foils

197Au(n4n)194Au ETHR=245 MeV

1

15

2

25

3

35

4

45

1 10 100 1000

Neutron energy [MeV]

1 GeV 07 GeV

15 GeV 07 GeV

20 GeV 07 GeV

1E-4

1E-3

1E-2

1E-1

1E+0 1E+1 1E+2 1E+3 1E+4

Neutron Energy [MeV]

Nu

mb

er o

f n

eutr

on

s

07 GeV

1 GeV

15 GeV

2 GeV

Neutron energy spectra for different beam energy

(longitudinal distance radial distance 3 cm)

Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV

Possible source of experiment simulation differences

Conclusions and outlooks

bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments

bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container

bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination

bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target

bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy

bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month

bull Experiments collected nice set of data for systematic benchmark comparison

The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala

Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all

We use activation foils from Au Bi In and Ta

Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)

measurements of cross-sections of (nxn)-reactions (with x up to 9)

The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV

Proposal was sent to EFNUDAT PAC for October meeting

• Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12
• Conclusions and outlooks
• Slide 14

00

05

10

15

20

25

0 5 10 15Radial distance from target axis [cm]

ex

p

yie

ld

sim

y

ield

20 GeV

15 GeV

10 GeV

07 GeV

High energy neutrons ndash threshold neutron reactions

We see clear dependence of MCNPX description quality on beam energy

Normalized to this foils

197Au(n4n)194Au ETHR=245 MeV

1

15

2

25

3

35

4

45

1 10 100 1000

Neutron energy [MeV]

1 GeV 07 GeV

15 GeV 07 GeV

20 GeV 07 GeV

1E-4

1E-3

1E-2

1E-1

1E+0 1E+1 1E+2 1E+3 1E+4

Neutron Energy [MeV]

Nu

mb

er o

f n

eutr

on

s

07 GeV

1 GeV

15 GeV

2 GeV

Neutron energy spectra for different beam energy

(longitudinal distance radial distance 3 cm)

Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV

Possible source of experiment simulation differences

Conclusions and outlooks

bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments

bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container

bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination

bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target

bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy

bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month

bull Experiments collected nice set of data for systematic benchmark comparison

The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala

Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all

We use activation foils from Au Bi In and Ta

Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)

measurements of cross-sections of (nxn)-reactions (with x up to 9)

The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV

Proposal was sent to EFNUDAT PAC for October meeting

• Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12
• Conclusions and outlooks
• Slide 14

1

15

2

25

3

35

4

45

1 10 100 1000

Neutron energy [MeV]

1 GeV 07 GeV

15 GeV 07 GeV

20 GeV 07 GeV

1E-4

1E-3

1E-2

1E-1

1E+0 1E+1 1E+2 1E+3 1E+4

Neutron Energy [MeV]

Nu

mb

er o

f n

eutr

on

s

07 GeV

1 GeV

15 GeV

2 GeV

Neutron energy spectra for different beam energy

(longitudinal distance radial distance 3 cm)

Higher beam energy rarr bigger contribution of neutrons with energy 7 MeV ndash 60 MeV

Possible source of experiment simulation differences

Conclusions and outlooks

bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments

bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container

bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination

bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target

bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy

bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month

bull Experiments collected nice set of data for systematic benchmark comparison

The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala

Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all

We use activation foils from Au Bi In and Ta

Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)

measurements of cross-sections of (nxn)-reactions (with x up to 9)

The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV

Proposal was sent to EFNUDAT PAC for October meeting

• Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12
• Conclusions and outlooks
• Slide 14

Conclusions and outlooks

bull EPT set-up and JINR Dubna accelerators are nice tools for ADTT benchmark experiments

bull Higher energy (E gt 05 MeV) neutron background is suppressed but low energy neutron background is produced by shielding container rarr study of low energy neutron production is possible only without shielding container

bull Low energy neutrons are produced by thermal and resonance region Inside container homogenous neutron field is produced It is possible to use it for integral number of produced neutron determination

bull Our obtained systematic for EPT set-up is possible to compare with systematic obtained for simple lead target

bull Spatial distribution of high energy neutrons is also described by simulation qualitatively quit well but there are quantitative differences We see clear dependence of description quality on beam energy

bull Low energy deuteron experiments (see O Svoboda talk) are consistent with our proton beam data We are waiting for first higher energy (4 GeV) deuteron experiment next month

bull Experiments collected nice set of data for systematic benchmark comparison

The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala

Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all

We use activation foils from Au Bi In and Ta

Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)

measurements of cross-sections of (nxn)-reactions (with x up to 9)

The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV

Proposal was sent to EFNUDAT PAC for October meeting

• Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12
• Conclusions and outlooks
• Slide 14

The Proposal of High-energy Neutron Cross-section Measurements at TSL in Uppsala

Significant voids in the cross-section libraries of (nxn)-reactions in many materialsFor example gold only (n2n)-reaction was measured in detail (n4n) reaction was measured only for energies lt 40 MeV Other (nxn) reactions with x gt 4 were not studied at all

We use activation foils from Au Bi In and Ta

Neutron beam at TSL in Uppsala is quasi-monoenergetic in the 11-174 MeV range (standard energies 11 22 47 95 143 174 MeV)

measurements of cross-sections of (nxn)-reactions (with x up to 9)

The neutron flux density is up to 5 105cm-2s-1 About the half of intensity is in the peakwith FWHM ~ 2-6 MeV

Proposal was sent to EFNUDAT PAC for October meeting

• Systematic studies of neutrons produced in the PbU assembly irradiated by relativistic protons and deuterons
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12
• Conclusions and outlooks
• Slide 14