SLAC RP current activities in radiation simulation and possible extension to ILC

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SLAC RP current activities in radiation
simulation and possible extension to ILC

• Fassò, N. Nakao, H. Vincke
• Aug. 2, 2005

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Our tools

• FLUKA and MARS
• Coupled electromagnetic/hadronic cascade
• Electric and magnetic fields
• Complex geometries
• Energy range keV to 1000 TeV
• Standard simulation tools for LHC
• Benchmarking
• Neutron spectrometry
• Activation measurements

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Current and already planned simulation studies in
RP

• LCLS
• shielding
• PPS stoppers
• radiation damage to electronics, permanent
  magnets, diagnostic equipment
• soil, groundwater and air activation,
  penetrations, maze design ..
• ILC
• SC cavity dark current
• radiation damage positron target, dpa
  calculations in collaboration with B. Wirth (LBL)

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FLUKA modelling of the LCLS undulator
Section of the geometry between two segments
AUTOCAD view
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Longitudinal and vertical distribution of total
dose. Max 110 Mrad/day
(assuming an electron intensity of 9.16 1011
electron/s)
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Transversal distribution of dose and neutron flux
At neutron flux max
At dose max
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MARS15 Monte Carlo simulation for LCLS
Arrangement of beam line components and magnetic
fields in MARS15
Secondary particle shower By beam loss at BYD1
bending magnet
14.1 GeV electrons Bending into the beam dump
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Prompt dose distribution in LCLS tunnel by MARS15
14.1GeV 30W beam loss at BYD1-bending magnet
Top view
Vertical
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Residual Dose Rate Activity around Beam Dump
by MARS15
14.1GeV 5kW electron beam
Below 1 mrem/h at top concrete
Along the beam line
Perpendicular to beam line
Attenuation of residual dose rate in concrete and
iron
Residual Dose Rate mSv/h (30-day operation
1-day cooling
3H (Tritium) 22Na activities in soil are
available from MARS15 simulation
results Activity estimation in ground water
Bottom side side
forward 0.22 0.60 0.19
0.69 Bq/cm3
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FLUKA Calculation for LCLS Two mirror system
Cross-sectional view through the FLUKA
geometry. FEE...Front End Enclosure WBORWhite
Beam Optic Room NEHNear Experimental Hall.
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LCLS Two mirror system - contd
Total effective dose rate in mrem/h
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Estimate of induced radioactivity around the FFTB
dump
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Residual radioactivity around the FFTB dump after
180 days of operation (28.5 GeV electrons on
dump, 2kW)
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Previous calculations performed for NLC by RP/SLAC

• Dose to Electronics in the NLC Beam Tunnel RP
  Note 9915
• Soil Groundwater Activation around the Beam
  Delivery System Tunnel RP Note 00-04
• Evaluation of Radiological Consequences from Air
  Activation at NLC BDS Tunnel RP Note 00-05
• Radiation Damage to Electronics Installed in
  Niches of the NLC Beam Tunnel RP Note 0006

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RADIATION DAMAGE TO ELECTRONICS IN THE BEAM
TUNNEL OF THE NEXT LINEAR COLLIDER1
- Non-radiation-hard electronics could be
severely damaged unless sufficiently shielded
against radiation. - Proposal Niches in the beam
tunnel wall which are shielded by layers of
polyethylene.
1 SLAC-PUB-8490
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ILC Possibilities for the next calculations

• Soil, air and groundwater activation
• Machine component activation
• Detector Background
• Shielding (personnel, environment, equipment)
• Dumps, collimators
• SC Quenching
• dose rates in occupied areas
• Anything else ?