Target/Beam Interaction

M. Apollonio, A. Dobbs - IC

27/11/2008 1MICE Target Workshop - IC

Motivations:• optimise secondary production minimising

dangerous losses in ISIS

• assess better orientation/shape of the shaft for secondary production

• a work at “four hands”:• A. Dobbs, ORBIT simulation of ISIS ring /

interaction with target / comparison with data taken from MICE shifts,

• MA, G4Beamline simulation of secondary production with a set of shafts

27/11/2008 2MICE Target Workshop - IC

ORBIT Results

27/11/2008 3MICE Target Workshop - IC

A. Dobbs

25/11/08 ORBIT Results, Adam Dobbs 4

Target Orientations (variable depths)

•“Short-Fat” – 1mm along z – axis, 10mm along x - axis

• “Long-Thin” – 10mm along z – axis, 1mm along x – axis (true orientation)

•“Reduced” – 1mm along z – axis, 1mm along x - axis

27/11/2008 4MICE Target Workshop - IC

x

y

s

25/11/08 ORBIT Results, Adam Dobbs 5

Injection losses MICE target

losses MICE target

losses

Short-Fat: 27mm above axis, -1 to 10ms

27/11/2008 5MICE Target Workshop - IC

zoom last 2 ms

25/11/08 ORBIT Results, Adam Dobbs 6

Long-Thin: 27mm above axis, -1 to 10ms(NB: present config)

27/11/2008 6MICE Target Workshop - IC

25/11/08 ORBIT Results, Adam Dobbs 7

Short-Fat: 27mm above axis, 8 to 10ms

27/11/2008 7MICE Target Workshop - IC

25/11/08 ORBIT Results, Adam Dobbs 8

Long-Thin: 27mm above axis, 8 to 10ms

27/11/2008 8MICE Target Workshop - IC

25/11/08 ORBIT Results, Adam Dobbs 9

Long-Thin: 26mm above axis, 8 to 10ms

27/11/2008 9MICE Target Workshop - IC

25/11/08 ORBIT Results, Adam Dobbs 10

Long-Thin: 27mm above axis, 250 rotation, 8 to 10ms

NB At present there remains an ambiguity in the direction of the rotation, clockwise or anti-clockwise. If / when this is resolved it will be published in an updated version of this document.

27/11/2008 10MICE Target Workshop - IC

25/11/08 ORBIT Results, Adam Dobbs 11

Reduced (1mm^2): 27mm above axis, 8 to 10ms

27/11/2008 11MICE Target Workshop - IC

25/11/08 ORBIT Results, Adam Dobbs 12

Reduced: 26mm above axis, 8 to 10ms

27/11/2008 12MICE Target Workshop - IC

25/11/08 ORBIT Results, Adam Dobbs 13

Reduced: 25mm above axis, 8 to 10ms

27/11/2008 13MICE Target Workshop - IC

25/11/08 ORBIT Results, Adam Dobbs 14

Reduced: 24mm above axis, 8 to 10ms

27/11/2008 14MICE Target Workshop - IC

Circular-solid 6mm radius: 27mm above axis, 8 to 10ms

27/11/2008 15MICE Target Workshop - IC

G4Beamline Studies

27/11/2008 16MICE Target Workshop - IC

M. Apollonio

27/11/2008 17MICE Target Workshop - IC

- is there a better shape for the target or orientation?- how many secondaries (pi) do we get at the Q1 bore (per impinging proton?)- what about materials?

ISIS p trajectory

Q1-

2-3

25o

MICE TGT

10 mm

10 mm

XZ

25 deg

Q1-TGTaxis

25 deg

lostto Q1

secondariesproduction20<theta<30propagation toplane Aacos(Pz/Ptot)>20&& acos(Pz/Ptot)<30

rotation &propagation to plane B

A A

B

C

shift & align with Q1-TGT axis

LONG SLIM

18

25 deg

25 deg

FAT SHORT

TILTED TGT10o / 25o

27/11/2008 19MICE Target Workshop - IC

25 deg

Cylinder: OD=6mm/ID=4.7 mm

Materials:Ti Be Al

27/11/2008 20MICE Target Workshop - IC

Tgt_long_slim_rot0: y:x Nprimaries=100M

27/11/2008 21MICE Target Workshop - IC

A

Tgt_long_slim: y:x rotation 25 deg + shift 4.226

27/11/2008 22MICE Target Workshop - IC

B

NB: this particles (ROOT file) are shooting towards Q1and can be usedas an input beam for further simulations

27/11/2008 23MICE Target Workshop - IC

at Q1 plane in Q1 bore

C

27/11/2008 24MICE Target Workshop - IC

27/11/2008 25MICE Target Workshop - IC

27/11/2008 MICE Target Workshop - IC

config POT POT/mm2 Dx H BaseArea V Q1 Q1/(POT/mm2)rho(mm) (mm) (mm^2) (mm^3) g cm-3

cyl_Ti 2.50E+08 1.04E+07 6 4 10.92457 43.69827 7351 7.06E-04 4.54cyl_Be 1.00E+08 4.17E+06 6 4 10.92457 43.69827 1792 4.30E-04 1.85cyl_Al 1.00E+08 4.17E+06 6 4 10.92457 43.69827 2059 4.94E-04 2.70long_slim 5.00E+08 1.25E+08 1 4 10 40 79817 6.39E-04 4.54short_fat 5.00E+08 1.25E+07 10 4 10 40 8184 6.55E-04 4.54tilt_25 1.00E+08 4.81E+06 5.2 4 10 40 3092 6.43E-04 4.54tilt_10 1.00E+08 9.19E+06 2.72 4 10 40 6010 6.54E-04 4.54

expectedp n pi+ pi- mu+ mu- gam e+e- TOT A/rho pi+

cyl_Ti 3.68E-04 2.67E-04 2.04E-05 6.82E-06 6.24E-06 1.92E-06 3.43E-05 1.34E-06 7.06E-04 10.54 2.04E-05cyl_Be 2.38E-04 1.30E-04 1.15E-05 3.36E-06 7.44E-06 2.16E-06 3.82E-05 2.40E-07 4.30E-04 4.88 9.42E-06cyl_Al 2.74E-04 1.60E-04 1.51E-05 3.12E-06 8.16E-06 3.60E-06 2.93E-05 7.20E-07 4.94E-04 10.00 1.93E-05long_slim 3.34E-04 2.36E-04 2.05E-05 6.39E-06 5.57E-06 1.54E-06 3.25E-05 1.52E-06 6.39E-04short_fat 3.43E-04 2.44E-04 2.06E-05 5.36E-06 6.16E-06 1.60E-06 3.27E-05 1.36E-06 6.55E-04tilt_25 3.23E-04 2.49E-04 1.44E-05 5.62E-06 1.12E-05 1.66E-06 3.41E-05 3.95E-06 6.43E-04tilt_10 3.41E-04 2.46E-04 1.47E-05 4.90E-06 1.08E-05 1.96E-06 3.14E-05 3.37E-06 6.54E-04

Q1 breakdown (/POT/mm2)

27/11/2008 27MICE Target Workshop - IC

CONCLUSIONS

- neither the shape nor the orientation of a target seem to alter significantly the production of secondaries to Q1- the overall material volume intercepted by the beam is the main parameter (reasonable) - material other than Ti (lower A/rho) generate less secondaries (in particular pions)-a good balance should be found between weight / mechanical stiffness / andpion production-a hollow cylinder is a good solution, certainly does not worsen the performances ofthe present configuration