Radiation shield of the beam line

1
Radiation shield of the beam line

• M. Yoshida
• Osaka Univ.
• 2006/11/14
• PRISM workshop _at_ Osaka Univ.

2
Radiation limit
3
NP Hall Layout
T1 target (30)
4
Residual dose at T1
R180cm
concrete
J-PARC hadron group
Air
Iron
5
J-PARC hadron group
6
Prompt Dose and Energy Deposition around PRISM
target

• Residual dose on COIL
• 1014 p/sec
• 30day irradiation / 1day cool
• ? 180 mSv/hr
• 1yr irradiation / 0.5yr cool
• ? 15 mSv/hr

7
Solenoid placement for vertical extraction
Service tunnel
Concrete/Iron shield
2200
2000

• Y

3818
1087
Z
Calculation of residual dose on concrete shield
is underway
8
Summary

• Radiation dose should be less than 1 mSv/hr at
  Service pit
• 30 target can shield by 1-meter-thick
  iron/concrete
• PRISM target (1.5 interaction length) would need
  more shield
• Estimation underway