dose measurements s. roesler (dgs-rp) collimation wg – ir3 passive absorbers 4 june 2012

Dose Measurements

S. Roesler(DGS-RP)

Collimation WG – IR3 passive absorbers4 June 2012

2

Outline


- Measurements 1) Ambient dose equivalent

• manual radiation survey (AD6 survey instrument), TS1 25/04/12• PMI readings

2) Absorbed dose• high level dosimetry (RPL dosimeters), 2011 (preliminary)

Thanks to: F.Jaquenod, C.Tromel, J.Tummer, H.Vincke

- Comparison IR3 vs IR7

- Scaling to nominal operational parameters and comparison to simulations for IR7

3Collimation WG – IR3 passive absorbers4 June 2012

IR3 – Ambient dose equivalent (survey 25/04/12)

Survey: 25/04/12Survey: 25/04/12

4Collimation WG – IR3 passive absorbers4 June 2012Survey: 25/04/12Survey: 25/04/12



12 µSv/h 6.5 µSv/h6.3 µSv/h 5.1 µSv/h

IR3 – Ambient dose equivalent (PMI readings 31/01/12)


IR3 – Absorbed dose (2011)

4.2 kGy (LSXL3-19) 5.2 kGy (LSXR3-19)



1.8 kGy (LSXL3-18) 1.8 kGy (LSXR3-18)



300 Gy(LSXL3-16)



5.2 kGy (LSXL3-13) 1.9 kGy (LSXR3-14)


Survey: 25/04/12Survey: 25/04/12




10.0 kGy (LSXL7-24) 9.2 kGy (LSXR7-22)



6.6 kGy (LSXL7-18) 5.6 kGy (LSXR7-18)


IR3 vs. IR7 – Absorbed dose D3 (2011)

10.0 kGy (LSXL7-24) 9.2 kGy (LSXR7-22)

4.2 kGy (LSXL3-19) 5.2 kGy (LSXR3-19)

IR3

IR7


IR3 vs. IR7 – Absorbed dose Q5 (2011)

IR3

IR7

6.6 kGy (LSXL7-18) 5.6 kGy (LSXR7-18)

5.2 kGy (LSXL3-13) 1.9 kGy (LSXR3-14)

18

IR7-Right

January 2011 January 2012 January 2013(Jan.2011 x fac.15)

January 2017(Jan.2011 x fac.54)

Element Contact AisleContact

B1/B2Aisle(1m)

Contact Aisle Contact Aisle

TCP.D6 10.0 1.2 31/76 6 150.0 18.0 540.0 65.0

TCP.C6 18.0 2.5 275/345 16 270.0 38.0 970.0 135.0

TCP.B6 31.0 3.1 300/560 40 465.0 47.0 1670.0 170.0

TCAPA 70.0 3.0 1100/860 35 1050.0 45.0 3780.0 160.0

TCAPB 13.0 1.2 145/203 13 195.0 18.0 700.0 65.0

TCSG.A6 8.0 1.5 450/450 28 120.0 23.0 430.0 80.0

TCAPC 65.0 2.5 870/840 16 975.0 38.0 3510.0 135.0

Dose equivalent rates (μSv/h)

Measurements Extrapolations


IR7 – Scaling to nominal parameters

19

Dose equivalent rates (μSv/h) (about two months cooling)

IR7-Right January 2013 Nominal(Jan.2013 x factor 3.6)

Element Contact Aisle Contact Aisle

TCP.D6 150.0 18.0 540.0 65.0

TCP.C6 270.0 38.0 970.0 135.0

TCP.B6 465.0 47.0 1670.0 170.0

TCAPA 1050.0 45.0 3780.0 160.0

TCAPB 195.0 18.0 700.0 65.0

TCSG.A6 120.0 23.0 430.0 80.0

TCAPC 975.0 38.0 3510.0 135.0

S.Roesler et al., EDMS 863919

• reasonable agreement for passive absorber • dose rate somewhat lower than predicted for first secondary collimator (due to initial settings?)



20

Dose equivalent rates (μSv/h)

IR3-Right January 2011 January 2012January 2013

(Jan.2011 x fac.15)January 2017

(Jan.2011 x fac.54)

Element Contact AisleContactB1/B2

Aisle(1m)

Contact Aisle Contact Aisle

TCP 13.0 0.3 180/88 6 195.0 4.5 702.0 16.0

TCAPA 24.0 0.7 440/360 8 360.0 11.0 1300.0 38.0

TCSG.5 7.5 0.2 195/172 12 113.0 3.0 405.0 11.0

MQWA.C 9.0 270/176 5 135.0 490.0

Measurements Extrapolations



21

Summary


• measurement results exist from 1) PMI ionization chambers (ambient dose equivalent) 2) dedicated radiation surveys (ambient dose equivalent) 3) HLD (absorbed dose in air)• direct comparison with simulation results for the operational conditions of 2011 not (yet) available, scaling of measured residual dose rates to nominal operational parameters indicated rough agreement (within factor 2-5) with simulations for IR7

• measurements show asymmetry between beam 1 and 2 for both IR3 and 7, doses higher by about a factor of two for beam 1• residual dose rates higher in IR7 as compared to IR3 (factor of 10 for passive absorber in in front of D3), ratio between both probably different for number of lost protons due to different layouts (e.g., number and location of collimators and absorbers)• absorbed doses upstream of D3 and Q5 yokes (at the locations of the dosimeters!) higher for IR7 (factor of 2-5), conclusions on peak dose requires simulations

dose measurements s. roesler (dgs-rp) collimation wg – ir3 passive absorbers 4 june 2012

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