horns, hadron production etc. (from hadron production to neutrino beam)
DESCRIPTION
200/9/26 NP02@Kyoto. Horns, Hadron production etc. (from hadron production to neutrino beam). A.K.Ichikawa KEK. Study on horns Changing n -beam energy Hadron production. Study on horns. 2.2m. Brief comment on the horn design status. Till now, in the beam MC simulation, - PowerPoint PPT PresentationTRANSCRIPT
Horns, Hadron production etc. (from hadron production
to neutrino beam)
A.K.Ichikawa
KEK
200/9/26 NP02@Kyoto
• Study on horns
• Changing -beam energy
• Hadron production
Study on horns
Brief comment on the horn design status Till now, in the beam MC simulation,
horns proposed in BNL-E889 was used.
2.2m
• Din = 1.9cm, I=250kA
• Sapphire target (Al2O3, =4g/cm3) D=0.64 cm, L=45cm
1st horn
c.f. K2K Din=3.0cm, I=250kA
In addition, heat load from radiation
Need realistic design work
production –Model-Momentum and angle of
=const.+const./<p>
MARS 50GeV, graphite
=0.038+0.31/p
MARS
50GeV : =0.038+0.31/p
30GeV : =0.038+0.33/p
GFLUKA+GCALOR
50GeV : =0.023+0.33/p
30GeV : =0.025+0.32/p
FLUKA2000
50GeV : =0.026+0.31/p
30GeV : =0.033+0.31/p
Momentum region of ’sw/ BNL-type horn, 2.5°OAB
’s contributing E<1.2GeV
>1.5GeV/c
>1.7GeV/c
4.4m
W/ fixed current,
r x 2 L x 2, Wx2 to obtain same optics.
2.2m
Din = 1.8cm
Din = 3.6cm
Scaling laws
BNL-type horn1
K2K horn1
OAB1o
WBB
w/ K2K horns
Din = 1.8cm
Din = 3cm
1m
Inner conductor 4.6cmI = 250 kA
1.7GeV
2GeV
2.5GeV
3GeV4m
Target in the horn
1m10m
4m
Target outside the horn
6cm, I=250kA
22cm, I=500kA
2.5m 1.4m
1m
36kA/cm2 @t=4mm 24kA/cm2 @t=3mm cf. K2K 35kA/cm2
66cm
One idea for ‘1st horn’
Till now, only 60% flux have been achieved…..
~3m
The other idea for ‘1st horn’
~250kA, Din~4cm ~500kA
Heat Load from Radiation
Graphite =1.8g/cm3
Water t=5mm
Air t=6mm
Inner cond.
Al t=4mm
In total,
34kJ/3.3E14 protons = 10 kW @ 0.3Hz
cf. K2K heat load in the target from the current
= 1.4 kW
(surface area ~x 7)
In the graphite target, 64kJ/3.3E14 protons in total
30mm
60mm
t~14o
ZR
ZR
Strategy to change peak energy
Change the neutrino beam energy
Side View
Top view
To SK/HK OAB 2°
OAB3°
Decay Volume
Unofficial
Dipole magnet
gap 1m×1m×1m
One method is changing the beam axis.
The other…. OAB+Bending Magnet
Oyabu’s talk
Hadron production model
jnubeam : neutrino beam simulation code
developed from K2K code
• DV shape : incorporate actual shape
• target & horns : still BNL-type.
• calculation of -flux at SK for all decays by weighting
• Hadron production model
1. Models built-in Geant3. e.g. GFLUKA..
2. Various models using Input via stdout | stdin.
> MARS | jnubeam
> FLUKA2000 | jnubeam
GFLUKA
MARS
FLUKA2000
OAB2.5o
Ep=50GeV
Graphite 0.74cm 45cm
Comparison of different proton energy and different models @ OAB2.5o
50 GeV
(1021POT)
30 GeV
(1021POT)
30 GeV
(1021 x 5/3POT)
GFLUKA 1.40 0.98 1.64
MARS 1.37 0.91 1.52
FLUKA2000 1.45 0.86 1.43
Absolute flux (E<1.5GeV)
x107/cm2/yr
e #(e)/#( E<1.5GeV)
50 GeV 30 GeV
GFLUKA 1.14% 0.87%
MARS 0.90% 0.86%
FLUKA2000 1.07% 0.83%
(Target is graphite but the dimension is BNL-type.)
Comparison of different proton energy and different models @ OAB2.5o
50 GeV 30 GeV #30 GeV/#50GeV
GFLUKA 63% 57% -9.5%
MARS 66% 61% 7.6%
FLUKA2000 64% 59% 7.8%
NC #NC/#CC(E<1.5GeV)
High Energy tail #(E>1.5GeV)/#(E<1.5GeV)
50 GeV 30 GeV #30GeV/#50GeV
GFLUKA 9.6% 7.6% 21%
MARS 11.5% 9.5% 17%
FLUKA2000 10.7% 8.8% 18%
Effects on SK observable
MARS 50 GeV
!!!! Graphite 45cm !!!!!
MARS 30 GeV
!!!! Graphite 45cm !!!!!
Pbeam=5~120 GeV/c
From R.Raja, NUFACT02
Summary or discussion item
• Horns : realistic design
gathering ideas
• Changing the beam energy
OAB vs OAB+bending
• Hadron production
MIPP
(30 GeV vs 50 GeV)
Supplement
Types for the 1st horn
(a) (b)
(c) (d)
MINOSK2K, CERN, BNL
(2nd horn)(-factory)
Beam DirectionFor both SK and possible HK.
Decay pipe
Event rate at SK MARS 50GeV
!!!Graphite 45cm target!!!