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Local Shielding around the PS Straight Section75 ? . Sanja Damjanovic, DGS-RP . LIU-PS Meeting, CERN, June 11, 2013 . FLUKA Geometry of the Local Shielding around Dummy Septum 15. PS Ejection Region with dummy septum 15 . SS16. SS15. b eam direction.
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Local Shielding around the PS Straight Section75 ? Sanja Damjanovic, DGS-RP LIU-PS Meeting, CERN, June 11, 2013 S. Damjanovic, CERN
FLUKA Geometry of the Local Shielding around Dummy Septum 15 PS Ejection Region with dummy septum 15 SS16 SS15 beam direction Soil,Stainless Steel, Aluminum, Concrete,Air, Steel l MMU15 MMU14 Local shielding in SS15 S. Damjanovic, CERN
Details of the Local Shielding around the Dummy Septum - lateral dimension: 200 cm - longitudinal dimension: 100 cm Proposal: implement similar shielding around SS75 in order to - vertical dimension: 220 cm - reduce the exposure of electronics in the RF alcove next to SS77 - reduce the prompt dose rate at the emergency exit towards EA S. Damjanovic, CERN
FLUKA Geometry of a possible Local Shielding around SS75 PS Sector 8 RF Alcove SS76 beam direction SS75 local shielding around SS75 Soil,Stainless Steel, Aluminum, Concrete,Steel MMU75 MMU74 MMU74 local shielding in SS75 S. Damjanovic, CERN
FLUKA Geometry of the PS Sector 8 including the RF Alcove SS77 - RF cavity 40MHz SS76 - RF cavity 10MHz SS75-local shielding BE/RF1 RF alcove BE/RF2 Soil,Stainless Steel, Aluminum, Concrete, Steel, Iron l existing concrete shielding block in front of the RF alcove: 160 cm long and 80 cm wide; BE/RF crates locally shielded by iron blocks S. Damjanovic, CERN
Assumptions for the Simulation - proton beam momentum of p=14 GeV - MTE operation at full beam intensity of 1013 p/s; total beam losses 2% - beam losses distributed according to the BLM measurements 83% of total loss in Sector 8 measured by BLM in SS75 - for MTE operation, about 13% of the total beam loss (2%) between SS75 and SS80 (with 11% of 13% in SS75) - absolute normalization: multiply the FLUKA results extracted per primary with the measured beam loss rate of 2.5×1010 p/s (0.25% of the primary 1013 p/s) for the annual estimate assume 2550 effective hours per year • For the simulation in the PS Sector 8 use the (normalized) beam loss distribution along sections SS75, 76, 77, 78, 79 and 80 measured by the BLMs as an input to the FLUKA simulations 6 S. Damjanovic, CERN
Continuous Transfer (CT) ejection – beam losses PS Report CERN-ATS-2011-007 (2011) CT losses MTE losses For CT operation highest beam losses in the region of SS31 (electrostatic septum) Large losses also in SS16 and SS75 SS75 Similar distribution of losses between SS75-80 with higher absolute values for the CT Conclusions to be drawn later for MTE operation would also be valid for CT
Can the local shielding around SS75 efficiently reduce the exposure of the electronics inside the RF technical alcove next to SS77 ? Physical Dose -long term ionizing damage- 1MeV-Eq Neutron Fluence -Displacement Damage- to answer the question these quantities should be followed High Energy (Ek>20 MeV) HadronFluence - Single Event Error -
Dose [Gy/y] distribution w/o and with local shielding in SS75 SS75 w/o local shielding 2-dim projections of Dose in y-z plane averaged over Δx=2 m height SS75 locally shielded for a nominal MTE operation year with 2.3×10+17 lost p in the region between SS75 and SS80 Distance along z-axis (cm) Dose [Gy/year] z-beam direction, x-vertical, y-horizontal direction SS75 Distance along y-axis (cm) Comparing the color codes, dose inside the RF alcove the same with and w/o local shielding around SS75 local shielding can hardly reduce downstream radiation (like for SS15) S. Damjanovic, CERN
Detailed comparison of Dose distribution inside the RF Alcove SS75 w/o local shielding SS75 locally shielded 2-dim projections of Dose in y-z plane averaged over Δx=2 m height for a nominal MTE operation year with 2.3×10+17 lost p in the region between SS75 and SS80 BE/RF2 Dose [Gy/year] Distance along z-axis (cm) BE/RF1 Hardly any reduction of the dose in the two BE/RF crates with the additional local shielding around SS75 Distance along y-axis (cm) Present shielding block reduces the dose inside the BE/RF1 and RF2 only by factors of 1.3 and 1.5, resp. S. Damjanovic, CERN
Dose distribution – solely contribution from the losses inside SS75 for a nominal MTE operation year with 0.8×2.3×10+17 lost p in the SS75 Lack of any shielding effect also visible in the isolated contribution from SS75 S. Damjanovic, CERN
Distribution of high energy (Ek>20 MeV) hadronfluence w/o and with local shielding in SS75 SS75 w/o local shielding SS75 locally shielded 2-dim projections in y-z plane averaged over Δx=2 m height Distance along z-axis (cm) h [1/cm2/year] for a nominal MTE operation year with 2.3×10+17 lost p distributed between SS75 and SS80 Distance along y-axis (cm) As for the dose, no effect of the shielding in the RF alcove S. Damjanovic, CERN
Detailed comparison of HE hadron fluence inside the RF Alcove SS75 w/o local shielding SS75 locally shielded 2-dim projectionsin y-z plane averaged over Δx=2 m height for a nominal MTE operation year with 2.3×10+17 lost p in the region between SS75 and SS80 BE/RF2 h [1/cm2/year] Distance along z-axis (cm) BE/RF1 No reduction of the hadronfluence in the two BE/RF crates with the additional local shielding around SS75 Distance along y-axis (cm) Present shielding block reduces the h-fluence inside the BE/RF1 and RF2 only by factors of 1.1 and 1.6, resp. S. Damjanovic, CERN
Distribution of 1MeV-eq neutron fluence w/o and with local shielding in SS75 SS75 w/o local shielding SS75 locally shielded 2-dim projections in y-z plane averaged over Δx=2 m height Distance along z-axis (cm) 1MeV-eq n [1/cm2/year] for a nominal MTE operation year with 2.3×10+17 lost p distributed between SS75 and SS80 Distance along y-axis (cm) Again no effect of the shielding in the RF alcove S. Damjanovic, CERN
Detailed comparison of 1MeV-eq neutron fluence in the RF Alcove SS75 w/o local shielding SS75 locally shielded 2-dim projectionsin y-z plane averaged over Δx=2 m height for a nominal MTE operation year with 2.3×10+17 lost p in the region between SS75 and SS80 BE/RF2 Distance along z-axis (cm) 1MeV-eq n [1/cm2/year] BE/RF1 No reduction of the 1MeV-eq neutron fluence in the two RF crates with the additional local shielding around SS75 Distance along y-axis (cm) Present shielding block reduces the 1MeV-eq-n-fluence inside the BE/RF1 and RF2 only by factors of 1.3 and 1.5, resp. S. Damjanovic, CERN
Fluence Spectra scored in the volume of the two BE/RF crates Local shielding around SS75 cannot reduce the exposure of the electronics inside the RF technical alcove Small effects of the present concrete block: reduction by factors 1.2 and 1.6 for the BE/RF1 and RF2 ,resp (see remarks below). Local shielding of two BE/RF crates by the Fe walls most effective way to reduce the exposure of the electronics (up to a factor of 10; see my slides shown at 10th MCWG meeting 04/2012)
Can the local shielding around SS75 efficiently reduce the prompt dose rate at the emergency exit towards the EA location (exit door D113)?
Stray radiation w/o and with local shielding in SS75 SS75 w/o local shielding 2-dim projections of Dose Rate in y-z plane averaged over Δx=2 m height SS75 locally shielded for beam loss rate 2.54×10+10 p/s between SS75 and SS80 Distance along z-axis (cm) Dose Rate [mSv/h] MMU75 Chicane z-beam direction, x-vertical, y-horizontal direction Distance along y-axis (cm) How much is the stray radiation reduced at the entrance to the Chicane ? S. Damjanovic, CERN
Stray radiation w/o and with local shielding in SS75 SS75 w/o local shielding 2-dim projections of Dose Rate in y-z plane averaged over Δx=2 m height SS75 locally shielded for beam loss rate 2.54×10+10 p/s between SS75 and SS80 Chicane Distance along z-axis (cm) MMU75 Dose Rate [mSv/h] z-beam direction, x-vertical, y-horizontal direction Distance along y-axis (cm) How much is the stray radiation reduced at the entrance to the Chicane ? S. Damjanovic, CERN
Dose Rates along the tunnel wall – side towards the EA 1 dim projections along z (beam direction) averaged over Δy=40 cm from the tunnel wall Prompt radiation at the entrance to the chicane reduced by only ~20% (already downstream enough to not get any benefit) is S. Damjanovic, CERN
Addendum Remarks on the present concrete shielding block S. Damjanovic, CERN
Dose [Gy/y] distribution w and w/o concrete block SS75 w/o local shielding 2-dim projections of Dose in y-z plane averaged over Δx=2 m height SS75 locally shielded for a nominal MTE operation year with 2.3×10+17 lost p in the region between SS75 and SS80 Distance along z-axis (cm) Dose [Gy/year] z-beam direction, x-vertical, y-horizontal direction Distance along y-axis (cm) Comparing the color codes, the dose inside the RF alcove similar with and w/o concrete block – size and position of the block ineffective S. Damjanovic, CERN
Distribution of high energy (Ek>20 MeV) hadronfluence with and w/o concrete block in front of the RF Alcove SS75 w/o local shielding SS75 locally shielded 2-dim projections in y-z plane averaged over Δx=2 m height Distance along z-axis (cm) h [1/cm2/year] for a nominal MTE operation year with 2.3×10+17 lost p distributed between SS75 and SS80 Distance along y-axis (cm) Comparing the color codes, the h-fluence inside the RF alcove similar with and w/o concrete block S. Damjanovic, CERN
Distribution of 1MeV-eq neutron fluence with and w/o concrete block in front of the RF Alcove SS75 w/o local shielding SS75 locally shielded 2-dim projections in y-z plane averaged over Δx=2 m height Distance along z-axis (cm) 1MeV-eq n [1/cm2/year] for a nominal MTE operation year with 2.3×10+17 lost p distributed between SS75 and SS80 Distance along y-axis (cm) Comparing the color codes, the 1MeV-eq neutron fluence inside the RF alcove similar with and w/o block S. Damjanovic, CERN
Small effects of the present concrete block: exposure of the electronics reduced only by factors of 1.2 and 1.6 for the BE/RF1 and RF2 ,resp. S. Damjanovic, CERN