1. Status of Radiation Protection Studies for the Linac4 beam dumps Joachim Vollaire DGS/RP

2. Outline  List of beam dumps for L4 commissioning and operation  Shielding for12 MeV beam dump  Shielding and strategy for 50 – 100 MeV dump  Status of main dump shielding analysis (160 MeV)  Status of LBS/LBE dumps shielding analysis  Conclusions EDMS 11732752L4 BCC meeting # 31, 24/22/2011

3. List of beam dumps for Linac4 EDMS 1173275L4 BCC meeting # 31, 24/22/20113  Temporary beam dumps for commissioning at different energies (12 MeV, 50 MeV and 100 MeV)  Main dump shielding with new layout and operational scenario (160 MeV)  LBS and LBE dumps (160 MeV) in the L4 transfer line (commissioning and measurements)

4. 12 MeV beam dumps EDMS 1173275L4 BCC meeting # 31, 24/22/20114  12 MeV beam (proton instead of H - )  Average current 6.5  A (4.05x10 13 p.s -1 )  Operational scenario (4 weeks 12 h/day) @ 6.5  A (4.06e13 pps) Beam

5. Residual dose rate 12 MeV beam dump EDMS 1173275L4 BCC meeting # 31, 24/22/20115 5 mn cooling time 1h cooling time1day cooling time

6. 50 MeV – 100 MeV beam dump EDMS 1173275L4 BCC meeting # 31, 24/22/20116  Re-location of the beam dump from the 50 MeV to the 100 MeV area  Move the dump with part of its shielding to limit personnel exposure  Best shielding material : lowest residual dose rate and activation of the surrounding structures  Operational scenario:  1 Month of operation @ 800 W/1.6 kW for 50 / 100 MeV

7. Geometry and studied configurations (I) EDMS 1173275L4 BCC meeting # 31, 24/22/20117  Shielding on a “Table”  Concrete bricks below the table (prevent tunnel activation)  Shielding on table would move with the dump…

8. Geometry and studied configurations (II) EDMS 1173275L4 BCC meeting # 31, 24/22/20118  Steel (iron) good for high energy neutrons  Borated poly. (5 %) high thermal neutron capture cross section  Marble low activation, “shield” the shielding Shielding 1Shielding 2Shielding 3 Configuration 1SteelConcreteMarble Configuration 2SteelBorated Poly.Marble Configuration 3Concrete Marble Configuration 4SteelConcrete Configuration 5Borated Poly. Marble Configuration 6Steel Marble Configuration 7SteelMarble

9. Neutron spectra out of the shielding EDMS 1173275L4 BCC meeting # 31, 24/22/20119  Configuration 2 leads to the lowest number of neutrons escaping the shielding  To confirm it is a good shielding looking at residual dose rate around the beam dump

10. Example residual dose rate (8 h cooling) EDMS 117327510 S1S2S3 C.1SSCOMB C.2SSBPMB C.3CO MB C.4SSCO C.5BP MB C.6SS MB C7SSMB Configuration 1Configuration 2 Configuration 3Configuration 4 50 MeV commissioning

11. Example residual dose rate (8 h cooling) EDMS 1173275Meeting, Date11 S1S2S3 C.1SSCOMB C.2SSBPMB C.3CO MB C.4SSCO C.5BP MB C.6SS MB C7SSMB Configuration 5Configuration 6 Configuration 7 50 MeV commissioning

12. Example residual dose rate (1 Week cooling) EDMS 1173275Meeting, Date12 S1S2S3 C.1SSCOMB C.2SSBPMB C.3CO MB C.4SSCO C.5BP MB C.6SS MB C7SSMB Configuration 1Configuration 2 Configuration 3Configuration 4 50 MeV commissioning

13. Example residual dose rate (1 Week cooling) EDMS 1173275L4 BCC meeting # 31, 24/22/201113 S1S2S3 C.1SSCOMB C.2SSBPMB C.3CO MB C.4SSCO C.5BP MB C.6SS MB C7SSMB Configuration 5Configuration 6 Configuration 7 50 MeV commissioning

14. Example residual dose rate (8 h cooling) EDMS 1173275L4 BCC meeting # 31, 24/22/201114 S1S2S3 C.1SSCOMB C.2SSBPMB C.3CO MB C.4SSCO C.5BP MB C.6SS MB C7SSMB Configuration 1 Horizontal cut Configuration 2 Horizontal cut Configuration 3 Horizontal cut Configuration 4 Horizontal cut 50 MeV commissioning

15. Example residual dose rate (8 h cooling) EDMS 1173275L4 BCC meeting # 31, 24/22/201115 S1S2S3 C.1SSCOMB C.2SSBPMB C.3CO MB C.4SSCO C.5BP MB C.6SS MB C7SSMB Configuration 5 Horizontal cut Configuration 6 Horizontal cut Configuration 7 Horizontal cut 50 MeV commissioning

16. Residual dose rate profile (1 day – 1 week) EDMS 1173275L4 BCC meeting # 31, 24/22/201116

17. Residual dose rate profile (1 day – 1 week) EDMS 1173275L4 BCC meeting # 31, 24/22/201117

18. Conclusions on shielding comparison EDMS 1173275L4 BCC meeting # 31, 24/22/201118 Configuration 2 best combination for short cooling times Weight ~ 5000 kg

19. Examples of use of Borated Poly and marble EDMS 1173275L4 BCC meeting # 31, 24/22/201119

20. Dose rate during transport EDMS 1173275L4 BCC meeting # 31, 24/22/201120  Low after week of cooling.  Quick disconnection + shielding (lead) to “plug” the opening in the shielding

21. Dose rate after 100 MeV run EDMS 1173275L4 BCC meeting # 31, 24/22/201121 1 month @ 100 MeV + 1 week CT 1 month @ 50 MeV + 1 week CT

22. Status of main dump study EDMS 1173275L4 BCC meeting # 31, 24/22/201122  New operational scenario and core design  New fellow since 01/10/2011 (Jan Blaha) working on dump shielding CoreCore + shielding (SS/BP/MB)

23. Some preliminary results available EDMS 1173275L4 BCC meeting # 31, 24/22/201123

24. Contact with RP colleagues in JPARC EDMS 1173275L4 BCC meeting # 31, 24/22/201124 M. Vretenar Chamonix

25. Status of LBE/LBS beam dumps EDMS 1173275L4 BCC meeting # 31, 24/22/201125 Gallery and adjacent building Access from Booster side Work carried out by H. Richter

26. Prompt dose calculations EDMS 1173275L4 BCC meeting # 31, 24/22/201126

27. Residual dose rate calculation and optimization EDMS 1173275L4 BCC meeting # 31, 24/22/201127 Residual H*(10)-rate [µSv/h] after commissioning ( 1h ) No optimization1 m deep dumpMarble plate Report being written

28. Conclusions EDMS 1173275L4 BCC meeting # 31, 24/22/201128  Good progress for the commissioning dumps (12 / 50 / 100 MeV)  Main dump shielding still to be specified (assuming 1 core for the entire lifetime of the facility for the time being ?)  LBS dump study being documented.  LBE study to be performed….