1. Shielding Studies using MARS Monte Carlo code Noriaki Nakao (SLAC) Jan. 6, 2005, WORKSHOP Machine-Detector Interface at ILC, SLAC

2. Shielding Calculations by MARS code  J-PARC 3GeV Proton Synchrotron (2001)  SLAC LCLS 14.1GeV electron dump line (2004)

3. J-PARC 3GeV Proton Synchrotron MARS14 (2001) Distributed beam loss using STRUCT (multi-turn tracking code) Beam line structure using MAD-MARS beam line builder Deep penetration calculation using 3-dimensional multi layer technique Prompt & Residual dose rate estimation  Shield thickness adjustment

4. MARS calculation geometry J-PARC 3GeV Synchrotron

5. Tunnel Cross Section at Injection and Collimator Region Vertical Horizontal

6. Beam loss distribution (Injection-collimator region)

7. Beam loss at injection septum vertical Horizontal Injection septum

8. Arc region geometry

9. Magnetic fields Bending Dipole Focusing or Defocusing Quadrupole

10. Flux estimation cells for MARS14 calculation

11. 1st layer Beam line module & Tunnel inside shield 3 dimensional multi layer calculation for deep penetration Leakage particles of previous layer are used as source In 10 times multiplied Store information of the particles leaked from geometry boundary (x,y,z,dx,dy,dz,E,W)

12. Leakage particles of previous layer are used as source of 10 times multiplied (splitting method) Store information of the particles leaked from geometry boundary (x,y,z,dx,dy,dz,E,W) 1st layer Beam line module & Tunnel inside shield 2nd layer Tunnel outside shield 3 dimensional multi layer calculation for deep penetration

13. 1st layer Beam line module & Tunnel inside shield 2nd layer Tunnel outside shield 3rd layer Soil around tunnel Leakage particles of previous layer are used as source of 10 times multiplied (splitting method) Store information of the particles leaked from geometry boundary (x,y,z,dx,dy,dz,E,W) 3 dimensional multi layer calculation for deep penetration

14. 1st layer Beam line module & Tunnel inside shield 2nd layer Tunnel outside shield 3rd layer Soil around tunnel Last layer Soil below ground level Leakage particles of previous layer are used as source of 10 times multiplied (splitting method) Store information of the particles leaked from geometry boundary (x,y,z,dx,dy,dz,E,W) 3 dimensional multi layer calculation for deep penetration Ground level

15. 0.25  Sv/h (0.025mrem/h) 5mSv/h (500mrem/h) Prompt dose rate [mSv/h]

16. SLAC LCLS - 14.1 GeV electron dump line MARS15(2004) Consider - Shielding, magnet, spoiler, collimator - Magnetic field Beam loss at (1) dump or (2) magnet Dose & particle flux distribution (color 2D)

17. Horizontal view Vertical view 30m Overview of MARS15 geometry for LCLS dump line SOIL AIR Concrete Muon shield Muon shield Hutch Beam dump AIR Muon shield Muon shield

18. (1) 14.1 GeV-5kW electrons into the beam dump

20. Residual dose rate [mSv/h] 30 day operation, 1 day cooling Muon flux [1/cm 2 /sec] Muon Flux Residual dose rate and muon flux around Beam dump (14.1GeV 5kW electron beam) Residual dose rate

21. Photon flux [1/cm2/sec] Electron flux [1/cm2/sec] Neutron flux [1/cm2/sec] Prompt dose [mSv/h]

22. (2) 30W electron loss at bending magnet Horizontal Vertical SUS pipe at Bending magnet 1mrad angle

23. Beam loss at SUS pipe of the 1 st -bending magnet)

24. Prompt dose and muon flux (14.1GeV 30W beam loss at 1 st -bending magnet) 100 10 1 rem/h 100 10 1 0.1 mrem/h

25. Summary Shielding studies were performed using MARS code for - J-PARC 3GeV Proton Synchrotron - SLAC LCLS Dump line Detailed structure of shielding, beam line modules, and magnetic fields were taken into account Spatial distributions were obtained for prompt & residual dose rates, and particle flux (e, , , n etc.)