EAR2 simulation update
Collaboration board meeting06.10.2011
Christina Weiss & Vasilis Vlachoudis
FLUKA Simulation for EAR2 2
Outlook
1. Introduction2. Results
Neutron Fluence Resolution Charged Particle Fluence & γ Background Collimation Implemented Beam Dump Neutron Fluence for Irradiation (@ 1.5 m)
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FLUKA Simulation for EAR2 3
INTRODUCTION
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FLUKA Simulation for EAR2 4
Latest simulations• Geometry in the simulations match the
design of the CE plansEAR2 @ 18.4 m
• Implemented Collimator:1. 2m Fe: conical shape 2. 1m PE borated: straight with 8 cm diameter
• Simulations have been performed for a setup:1. Without additional moderator at the bottom of the neutron tube (97e+6 primaries)
2. With Moderator at the bottom of the tube (52e+6 primaries) : Polyethylene (dmin = 1 cm)
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FLUKA Simulation for EAR2 5
RESULTSNeutron Fluence
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FLUKA Simulation for EAR2 6
Neutron Fluence
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In total the neutron fluence is reduced by about 32 % when using an additional moderator for EAR2
FLUKA Simulation for EAR2 7
Neutron Fluence Comparison to EAR1
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Energy Interval
EAR1 EAR2Without Moderator
Gain
[ n / cm2 / pulse ]
Error[%]
[ n / cm2 / pulse ]
Error[%]
0.1 – 10 eV 5.11e4 0.3 8.01e5 2.6 15.7
0.01 – 1 keV 4.07e4 0.3 1.09e6 1.8 26.8
1 – 100 keV 5.03e4 0.2 1.39e6 1.7 27.6
0.1 – 10 MeV 1.77e5 0.1 2.95e6 1.1 16.7
10 – 100 MeV 2.64e4 0.3 4.03e5 2.7 15.2
> 100 MeV 4.71e4 0.3 8.76e4 5.9 1.9
Total Energy Range
4.68e5 0.08 7.82e6 0.9 16.7
Reference for EAR1 : FLUKA Simulations with fission collimator (d = 8 cm)
FLUKA Simulation for EAR2 8
RESULTSResolution
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FLUKA Simulation for EAR2 9
Time – Energy Relation
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FLUKA Simulation for EAR2 10
Time – Energy Relation
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FLUKA Simulation for EAR2 11
Resolution in comparison with EAR1
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Neutron Energy EAR1 EAR2No Moderator
EAR2With Moderator
FWHM [cm] FWHM [cm] FWHM [cm]
1 eV 3 4 2
1 keV 5.1 8 7
1 MeV 34.1 38 36
Neutron Fluence is reduced by about 32 % if a Moderator in this form is used
Neutron Energy EAR1: 187.5 m EAR2: 18.9 mNo Moderator
EAR2: 18.9 mWith Moderator
ΔE / E ΔE / E ΔE / E
1 eV 3.0e-4 4.3e-3 2.2e-3
1 keV 5.4e-4 8.5e-3 7.5e-3
1 MeV 3.6e-3 4.1e-2 3.9e-2
FLUKA Simulation for EAR2 12
RESULTSCharged Particle Fluence
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FLUKA Simulation for EAR2 13
Charged Particle Fluence
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FLUKA Simulation for EAR2 14
Magnet
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pmax = 1.205 [GeV/c] protons
B = 0.2 [Tm]
Collimator
h = 4.60 [m]
Possible Position for a magnet: Assumed magnet length: l = 1 [m]
FLUKA Simulation for EAR2 15
Photon Fluence
EAR2 EAR1
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FLUKA Simulation for EAR2 16
Arrival Time
EAR2 EAR1
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FLUKA Simulation for EAR2 17
RESULTSCollimation
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FLUKA Simulation for EAR2 18
Neutron Beam Profile
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Collimator:1. 2m Fe: conical shape 2. 1m PE borated: straight with 8 cm diameter
FLUKA Simulation for EAR2 19
RESULTSBeam Dump – Backscattered Neutrons
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FLUKA Simulation for EAR2 20
Beam DumpBackscattered Neutrons
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• 1.5 m of Fe surrounded by• 40 cm of borated PE• 1 mm of Cd at the entrance
FLUKA Simulation for EAR2 21
RESULTSNeutron Fluence at 1.5 m from the target center – Material Irradiation
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FLUKA Simulation for EAR2 22
Neutron Tube has 32 cm diameter at 1.5 m from the target center
Neutron Fluence for Irradiation
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Total: 2.5e10 n / cm^2 / 7e12 ppp
FLUKA Simulation for EAR2 23
Thank you for your attention!
6 October 2011
Energy Interval EAR1 EAR2Without Moderator
Gain
[ n / cm2 / pulse ]
Error[%]
[ n / cm2 / pulse ]
Error[%]
0.1 – 10 eV 5.11e4 0.3 8.01e5 2.6 15.7
0.01 – 1 keV 4.07e4 0.3 1.09e6 1.8 26.8
1 – 100 keV 5.03e4 0.2 1.39e6 1.7 27.6
0.1 – 10 MeV 1.77e5 0.1 2.95e6 1.1 16.7
10 – 100 MeV 2.64e4 0.3 4.03e5 2.7 15.2
> 100 MeV 4.71e4 0.3 8.76e4 5.9 1.9
Total Energy Range
4.68e5 0.08 7.82e6 0.9 16.7
Reference for EAR1 : FLUKA Simulations with fission collimator (d = 8 cm)
Neutron Fluence Comparison