Status of Radiation Protection Studies for the Linac4 beam dumps Joachim Vollaire DGS/RP.
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Transcript of Status of Radiation Protection Studies for the Linac4 beam dumps Joachim Vollaire DGS/RP.
Status of Radiation Protection Studies for the Linac4 beam dumps
Joachim Vollaire
DGS/RP
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 11732752 L4 BCC meeting # 31, 24/22/2011
L4 BCC meeting # 31, 24/22/2011
List of beam dumps for Linac4
EDMS 11732753
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)
L4 BCC meeting # 31, 24/22/2011
12 MeV beam dumps
EDMS 11732754
12 MeV beam (proton instead of H-) Average current 6.5 mA (4.05x1013
p.s-1) Operational scenario (4 weeks 12
h/day) @ 6.5 mA (4.06e13 pps)
Beam
Beam
L4 BCC meeting # 31, 24/22/2011
Residual dose rate 12 MeV beam dump
EDMS 11732755
5 mn cooling time
1h cooling time 1day cooling time
L4 BCC meeting # 31, 24/22/2011
50 MeV – 100 MeV beam dump
EDMS 11732756
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
L4 BCC meeting # 31, 24/22/2011
Geometry and studied configurations (I)
EDMS 11732757
Shielding on a “Table” Concrete bricks below the table (prevent tunnel
activation) Shielding on table would move with the dump…
L4 BCC meeting # 31, 24/22/2011
Geometry and studied configurations (II)
EDMS 11732758
Steel (iron) good for high energy neutrons Borated poly. (5 %) high thermal neutron capture
cross section Marble low activation, “shield” the shielding
Shielding 1 Shielding 2 Shielding 3
Configuration 1 Steel Concrete Marble
Configuration 2 Steel Borated Poly. Marble
Configuration 3 Concrete Concrete Marble
Configuration 4 Steel Concrete Concrete
Configuration 5 Borated Poly. Borated Poly. Marble
Configuration 6 Steel Steel Marble
Configuration 7 Steel Marble Marble
L4 BCC meeting # 31, 24/22/2011
Neutron spectra out of the shielding
EDMS 11732759
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
Example residual dose rate (8 h cooling)
EDMS 117327510
S1 S2 S3
C.1 SS CO MB
C.2 SS BP MB
C.3 CO CO MB
C.4 SS CO CO
C.5 BP BP MB
C.6 SS SS MB
C7 SS MB MB
Configuration 1 Configuration 2
Configuration 3 Configuration 4
50 MeV commissioning
Example residual dose rate (8 h cooling)
EDMS 1173275Meeting, Date11
S1 S2 S3
C.1 SS CO MB
C.2 SS BP MB
C.3 CO CO MB
C.4 SS CO CO
C.5 BP BP MB
C.6 SS SS MB
C7 SS MB MB
Configuration 5 Configuration 6
Configuration 7
50 MeV commissioning
Example residual dose rate (1 Week cooling)
EDMS 1173275Meeting, Date12
S1 S2 S3
C.1 SS CO MB
C.2 SS BP MB
C.3 CO CO MB
C.4 SS CO CO
C.5 BP BP MB
C.6 SS SS MB
C7 SS MB MB
Configuration 1 Configuration 2
Configuration 3 Configuration 4
50 MeV commissioning
L4 BCC meeting # 31, 24/22/2011
Example residual dose rate (1 Week cooling)
EDMS 117327513
S1 S2 S3
C.1 SS CO MB
C.2 SS BP MB
C.3 CO CO MB
C.4 SS CO CO
C.5 BP BP MB
C.6 SS SS MB
C7 SS MB MB
Configuration 5 Configuration 6
Configuration 7
50 MeV commissioning
L4 BCC meeting # 31, 24/22/2011
Example residual dose rate (8 h cooling)
EDMS 117327514
S1 S2 S3
C.1 SS CO MB
C.2 SS BP MB
C.3 CO CO MB
C.4 SS CO CO
C.5 BP BP MB
C.6 SS SS MB
C7 SS MB MB
Configuration 1Horizontal cut
Configuration 2Horizontal cut
Configuration 3Horizontal cut
Configuration 4Horizontal cut
50 MeV commissioning
L4 BCC meeting # 31, 24/22/2011
Example residual dose rate (8 h cooling)
EDMS 117327515
S1 S2 S3
C.1 SS CO MB
C.2 SS BP MB
C.3 CO CO MB
C.4 SS CO CO
C.5 BP BP MB
C.6 SS SS MB
C7 SS MB MB
Configuration 5Horizontal cut
Configuration 6Horizontal cut
Configuration 7Horizontal cut
50 MeV commissioning
L4 BCC meeting # 31, 24/22/2011
Residual dose rate profile (1 day – 1 week)
EDMS 117327516
L4 BCC meeting # 31, 24/22/2011
Residual dose rate profile (1 day – 1 week)
EDMS 117327517
L4 BCC meeting # 31, 24/22/2011
Conclusions on shielding comparison
EDMS 117327518
Configuration 2best combination for short cooling
timesWeight ~ 5000 kg
L4 BCC meeting # 31, 24/22/2011
Examples of use of Borated Poly and marble
EDMS 117327519
L4 BCC meeting # 31, 24/22/2011
Dose rate during transport
EDMS 117327520
Low after week of cooling. Quick disconnection + shielding (lead) to
“plug” the opening in the shielding
L4 BCC meeting # 31, 24/22/2011
Dose rate after 100 MeV run
EDMS 117327521
1 month @ 100 MeV + 1 week CT
1 month @ 50 MeV + 1 week CT
L4 BCC meeting # 31, 24/22/2011
Status of main dump study
EDMS 117327522
New operational scenario and core design New fellow since 01/10/2011 (Jan Blaha)
working on dump shielding
Core Core + shielding (SS/BP/MB)
L4 BCC meeting # 31, 24/22/2011
Some preliminary results available
EDMS 117327523
L4 BCC meeting # 31, 24/22/2011
Contact with RP colleagues in JPARC
EDMS 117327524
M. Vretenar Chamonix
L4 BCC meeting # 31, 24/22/2011
Status of LBE/LBS beam dumps
EDMS 117327525
Gallery and adjacent building
Access from Booster side
Work carried out by H. Richter
L4 BCC meeting # 31, 24/22/2011
Prompt dose calculations
EDMS 117327526
L4 BCC meeting # 31, 24/22/2011
Residual dose rate calculation and optimization
EDMS 117327527
Residual H*(10)-rate [µSv/h] after commissioning (1h)
No optimization 1 m deep dump Marble plate
Report being written
L4 BCC meeting # 31, 24/22/2011
Conclusions
EDMS 117327528
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….