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….