Local Shielding around the PS Straight Section75 ?
description
Transcript of Local Shielding around the PS Straight Section75 ?
![Page 1: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/1.jpg)
S. Damjanovic, CERN 1
Local Shielding around the PS Straight Section75 ?
Sanja Damjanovic, DGS-RP
LIU-PS Meeting, CERN, June 11, 2013
![Page 2: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/2.jpg)
S. Damjanovic, CERN 2
FLUKA Geometry of the Local Shielding around Dummy Septum 15
beam direction
SS15
SS16
Soil, Stainless Steel, Aluminum, Concrete, Air, Steel l
Local shielding in SS15
PS Ejection Region with dummy septum 15
MMU14 MMU15
![Page 3: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/3.jpg)
S. Damjanovic, CERN 3
Details of the Local Shielding around the Dummy Septum
- longitudinal dimension: 100 cm
- lateral dimension: 200 cm
- vertical dimension: 220 cm
Proposal: implement similar shielding around SS75 in order to - reduce the exposure of electronics in the RF alcove next to SS77 - reduce the prompt dose rate at the emergency exit towards EA
![Page 4: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/4.jpg)
S. Damjanovic, CERN 4
FLUKA Geometry of a possible Local Shielding around SS75
Soil, Stainless Steel, Aluminum, Concrete, Steel
beam direction
SS75
PS Sector 8
SS76
local shielding
around SS75
RF Alcove
local shielding in SS75
MMU74
MMU75
MMU74
![Page 5: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/5.jpg)
S. Damjanovic, CERN 5
FLUKA Geometry of the PS Sector 8 including the RF Alcove
Soil, Stainless Steel, Aluminum, Concrete, Steel, Iron l
RF alcove
BE/RF1
BE/RF2
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
SS77 - RF cavity 40MHzSS76 - RF cavity
10MHzSS75-local shielding
![Page 6: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/6.jpg)
6
- for MTE operation, about 13% of the total beam loss (2%) between SS75 and SS80 (with 11% of 13% in SS75)
Assumptions for the Simulation
- 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
- 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
- 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
6S. Damjanovic, CERN
83% of total loss in Sector 8 measured by BLM in SS75
![Page 7: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/7.jpg)
Continuous Transfer (CT) ejection – beam losses
CT lossesMTE losses
For CT operation highest beam losses in the region of SS31 (electrostatic septum) Large losses also in SS16 and SS75
PS Report CERN-ATS-2011-007 (2011)
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
SS75
![Page 8: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/8.jpg)
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-
High Energy (Ek>20 MeV) Hadron Fluence - Single Event Error -
to answer the question these quantities should be followed
![Page 9: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/9.jpg)
S. Damjanovic, CERN 9
Dose [Gy/y] distribution w/o and with local shielding in SS75 2-dim projections of Dose in y-z plane averaged over Δx=2 m height
Comparing the color codes, dose inside the RF alcove the same with and w/o local shielding around SS75
Dose [G
y/year]
SS75 w/o local shielding
Distance along y-axis (cm)
Dis
tanc
e al
ong
z-ax
is (c
m)
SS75 locally shielded
z-beam direction, x-vertical, y-horizontal direction
for a nominal MTE operation year with 2.3×10+17 lost p in the region between SS75 and SS80
SS
75
local shielding can hardly reduce downstream radiation (like for SS15)
![Page 10: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/10.jpg)
S. Damjanovic, CERN 10
Detailed comparison of Dose distribution inside the RF Alcove
2-dim projections of Dose in y-z plane averaged over Δx=2 m height
SS75 w/o local shielding SS75 locally shielded
Dose [G
y/year]
Distance along y-axis (cm)
Dis
tanc
e al
ong
z-ax
is (c
m)
BE/RF2
BE/RF1
options RF1 - Dose [Gy/year] RF2 - Dose [Gy/year]
Option I – w/o Local Shielding around SS75 2.7±0.2 5.4±0.3
Option II – with Local Shielding around SS75 2.9±0.2 5.0±0.3
Option III – without present block in front of alcove 4.0±0.3 7.7±0.3
Hardly any reduction of the dose in the two BE/RF crates with the additional local shielding around SS75
Present shielding block reduces the dose inside the BE/RF1 and RF2 only by factors of 1.3 and 1.5, resp.
for a nominal MTE operation year with 2.3×10+17 lost p in the region between SS75 and SS80
![Page 11: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/11.jpg)
S. Damjanovic, CERN 11
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
options RF1 - Dose [Gy/year] RF2 - Dose [Gy/year]
all sources contribution from source in SS75 all sources contribution from
source in SS75
w/o Local Shielding around SS75 2.7 1.1 5.4 2.5
with Local Shielding around SS75 2.9 1.2 5.0 2.0
Lack of any shielding effect also visible in the isolated contribution from SS75
![Page 12: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/12.jpg)
S. Damjanovic, CERN 12
Distribution of high energy (Ek>20 MeV) hadron fluence w/o and with local shielding in SS75
2-dim projections in y-z plane averaged over Δx=2 m height
As for the dose, no effect of the shielding in the RF alcove
Distance along y-axis (cm)
for a nominal MTE operation year with 2.3×10+17 lost p distributed between SS75 and SS80
h [1/cm2/year]
SS75 w/o local shielding
Dis
tanc
e al
ong
z-ax
is (c
m)
SS75 locally shielded
![Page 13: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/13.jpg)
S. Damjanovic, CERN 13
Detailed comparison of HE hadron fluence inside the RF Alcove
2-dim projectionsin y-z plane averaged over Δx=2 m height
SS75 w/o local shielding SS75 locally shielded
h [1/cm2/year]
Distance along y-axis (cm)
Dis
tanc
e al
ong
z-ax
is (c
m)
BE/RF2
BE/RF1
options RF1 - h [1/cm2/year] RF2 - h [1/cm2/year]
Option I – w/o Local Shielding around SS75 8.3×109 1.3×1010
Option II – with Local Shielding around SS75 8.3×109 1.3×1010
Option III – without present block in front of alcove 9.3×109 2.1×1010
No reduction of the hadron fluence in the two BE/RF crates with the additional local shielding around SS75
for a nominal MTE operation year with 2.3×10+17 lost p in the region between SS75 and SS80
Present shielding block reduces the h-fluence inside the BE/RF1 and RF2 only by factors of 1.1 and 1.6, resp.
![Page 14: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/14.jpg)
S. Damjanovic, CERN 14
Distribution of 1MeV-eq neutron fluence w/o and with local shielding in SS75
2-dim projections in y-z plane averaged over Δx=2 m height
for a nominal MTE operation year with 2.3×10+17 lost p distributed between SS75 and SS80
1MeV-eq n [1/cm
2/year]
SS75 w/o local shielding
Distance along y-axis (cm)
Dis
tanc
e al
ong
z-ax
is (c
m)
SS75 locally shielded
Again no effect of the shielding in the RF alcove
![Page 15: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/15.jpg)
S. Damjanovic, CERN 15
Detailed comparison of 1MeV-eq neutron fluence in the RF Alcove
2-dim projectionsin y-z plane averaged over Δx=2 m height
SS75 w/o local shielding SS75 locally shielded 1MeV-eq n [1/cm
2/year]
Distance along y-axis (cm)
Dis
tanc
e al
ong
z-ax
is (c
m)
BE/RF2
BE/RF1
options RF1 – 1MeV-eq neutron [1/cm2/year]
RF2 – 1MeV-eq neutron [1/cm2/year]
Option I – w/o Local Shielding around SS75 9.7×1010 1.2×1011
Option II – with Local Shielding around SS75 9.5×1010 1.2×1011
Option III – without present block in front of alcove 1.2×1011 1.9×1011
No reduction of the 1MeV-eq neutron fluence in the two RF crates with the additional local shielding around SS75
for a nominal MTE operation year with 2.3×10+17 lost p in the region between SS75 and SS80
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.
![Page 16: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/16.jpg)
Fluence Spectra scored in the volume of the two BE/RF crates
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)
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 around SS75 cannot reduce the exposure of the electronics inside the RF technical alcove
![Page 17: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/17.jpg)
Can the local shielding around SS75 efficiently reduce the prompt dose rate at the emergency exit towards the EA location (exit door D113)?
![Page 18: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/18.jpg)
S. Damjanovic, CERN 18
Stray radiation w/o and with local shielding in SS75 2-dim projections of Dose Rate in y-z plane averaged over Δx=2 m height
Dose R
ate [mS
v/h]
SS75 w/o local shielding
Distance along y-axis (cm)
Dis
tanc
e al
ong
z-ax
is (c
m)
SS75 locally shielded
z-beam direction, x-vertical, y-horizontal direction
for beam loss rate 2.54×10+10 p/s between SS75 and SS80
MM
U75Chicane
How much is the stray radiation reduced at the entrance to the Chicane ?
![Page 19: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/19.jpg)
S. Damjanovic, CERN 19
Stray radiation w/o and with local shielding in SS75 2-dim projections of Dose Rate in y-z plane averaged over Δx=2 m height
Dose R
ate [mS
v/h]
SS75 w/o local shielding
Distance along y-axis (cm)
Dis
tanc
e al
ong
z-ax
is (c
m)
SS75 locally shielded
z-beam direction, x-vertical, y-horizontal direction
for beam loss rate 2.54×10+10 p/s between SS75 and SS80
MM
U75Chicane
How much is the stray radiation reduced at the entrance to the Chicane ?
![Page 20: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/20.jpg)
S. Damjanovic, CERN 20
Dose Rates along the tunnel wall – side towards the EA
Prompt radiation at the entrance to the chicane reduced by only ~20%
1 dim projections along z (beam direction) averaged over Δy=40 cm from the tunnel wall
(already downstream enough to not get any benefit) is
![Page 21: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/21.jpg)
Addendum Remarks on the present concrete shielding block
S. Damjanovic, CERN 21
![Page 22: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/22.jpg)
S. Damjanovic, CERN 22
Dose [Gy/y] distribution w and w/o concrete block 2-dim projections of Dose in y-z plane averaged over Δx=2 m height
Comparing the color codes, the dose inside the RF alcove similar with and w/o concrete block – size and position of the block ineffective
Dose [G
y/year]
SS75 w/o local shielding
Distance along y-axis (cm)
Dis
tanc
e al
ong
z-ax
is (c
m)
SS75 locally shielded
z-beam direction, x-vertical, y-horizontal direction
for a nominal MTE operation year with 2.3×10+17 lost p in the region between SS75 and SS80
![Page 23: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/23.jpg)
S. Damjanovic, CERN 23
Distribution of high energy (Ek>20 MeV) hadron fluence with and w/o concrete block in front of the RF Alcove
2-dim projections in y-z plane averaged over Δx=2 m height
Comparing the color codes, the h-fluence inside the RF alcove similar with and w/o concrete block
Distance along y-axis (cm)
for a nominal MTE operation year with 2.3×10+17 lost p distributed between SS75 and SS80
h [1/cm2/year]
SS75 w/o local shielding
Dis
tanc
e al
ong
z-ax
is (c
m)
SS75 locally shielded
![Page 24: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/24.jpg)
S. Damjanovic, CERN 24
Distribution of 1MeV-eq neutron fluence with and w/o concrete block in front of the RF Alcove
2-dim projections in y-z plane averaged over Δx=2 m height
Comparing the color codes, the 1MeV-eq neutron fluence inside the RF alcove similar with and w/o block
for a nominal MTE operation year with 2.3×10+17 lost p distributed between SS75 and SS80
1MeV-eq n [1/cm
2/year]
SS75 w/o local shielding
Distance along y-axis (cm)
Dis
tanc
e al
ong
z-ax
is (c
m)
SS75 locally shielded
![Page 25: Local Shielding around the PS Straight Section75 ?](https://reader035.fdocuments.net/reader035/viewer/2022062305/56816105550346895dd04b78/html5/thumbnails/25.jpg)
S. Damjanovic, CERN 25
h [1/cm2/y] RF1 - h [1/cm2/year] RF2 - h [1/cm2/year]
Option I – w/o Local Shielding around SS75 8.3×109 1.3×1010
Option II – with Local Shielding around SS75 8.3×109 1.3×1010
Option III – without present block in front of alcove 9.3×109 2.1×1010
1MeV-eq neutron [1/cm2/y] RF1 – 1MeV-eq neutron [1/cm2/year]
RF2 – 1MeV-eq neutron [1/cm2/year]
Option I – w/o Local Shielding around SS75 9.7×1010 1.2×1011
Option II – with Local Shielding around SS75 9.5×1010 1.2×1011
Option III – without present block in front of alcove 1.2×1011 1.9×1011
Dose RF1 - Dose [Gy/year] RF2 - Dose [Gy/year]
Option I – w/o Local Shielding around SS75 2.7±0.2 5.4±0.3
Option II – with Local Shielding around SS75 2.9±0.2 5.0±0.3
Option III – without present block in front of alcove 4.0±0.3 7.7±0.3
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.