1. SPS dose forecast for foreseen safety installations
Elisa Guillermain

2. What is needed and why ?

3. Concerned Projects Sprinkler system Fire safety system TETRA beacons
Emergency lights
Safety system in the SPS
At the transport wall / ceiling

4. Safety system – Emergency lights
All around the SPS ring
(and will be installed in all CERN tunnels)
LED emergency lights approx. every 14 meters to be tested, at height 1,2 meters at the transport side wall
Also : In the caverns and high height areas
LED emergency lights at height 2,4 meters minimum
April 2016

5. Fire safety system – Fire doors
Exact position being currently defined
In between ring and TAs
In between LSS and arc
In between sextants
Temporary position available in EDMS
Position might vary ± 10 meters
Maximum 450 m in between two doors
Also, doors for compartmentalization of high dose area: Will include fire safety elements ?? To double check with Michael !
At fire doors : Magnets, switches, flashes, junction boxes to be tested
August 2016

6. Fire safety system - Sprinkler system
In the LSS, up to first fire doors
In both levels of the TAs
In shafts
Sprinkler heads at highest point in the ceiling (if possible) every 3 meters (more or less..) to be tested
Main pipe: Ø mm max.
Branch: Ø 25-32mm max.
Sprinkler heads
May 2016

7. Fire safety system – Emergency glass break and speakers
All around the SPS ring
Glue to be tested for connection of pipes all over the ring
Glass break every 56 meters to be tested
Speakers every 28 meters to be tested
Will have same positions than emergency lights
Speaker
Glass
break
August 2016

8. Geolocalisation system – TETRA beacons
All around the SPS ring
About 120 in the ring
(and 1000 installed all over CERN)
System already installed
Exact positions are available
May 2016

9. Why estimate forecasted doses in SPS ?
For all these system:
Check if the equipment will survive in the hot areas of SPS
If yes, for how long ?
Starting after LS2 (2021), for 5, 10, 20, 40 years lifetime !
Also : check the equipment suitability for the low doses area.
Dose steps during the irradiation test need to be representative of most dose conditions in the SPS.
Would the equipment be suitable for low dose area, even if not for high doses ? Install some equipment only where the expected dose is suitable with their radiation resistance ?
Irradiation tests shall be performed in short schedule, mainly for the fire safety system, including sprinklers, because the procurement process is to be launched soon (MS + PE)

10. Dose monitoring in SPS

11. Monitoring : BLM in SPS BLM placement At the beam line level
Upstream quadrupoles (position 08)
Additional positions exists
Some of the BLM were moved below magnets (before 2010 ? Not 100% sure), but this is not taken into account here
Data available for each whole year,
From 2010 up to 2015 (included)
Is this BLM type reliable ? Seems that yes…

12. Monitoring : RPL in SPS
RPL placement:
At the beam line level (coils), downstream quadrupoles (position 20)
At the cable trays level, upstream quadrupoles (position 08),
Additional positions in the LSS,
At the beam line level and at cable tray level (position estimated)
Some missing location in Sextant 6
RPL at coils n° 23, 24, 25
RPL at trays n° 09T and 10T
Data
From beginning 2011 up to LSI start (mid ) – 2 years
Data
From to > No ! – Exposed for 2 years ? 1 year ?
In the following : Two years data, whole 2014 and whole 2015

13. BLM and RPL in SPS ring Cable tray RPL position 08 Cable tray RPL
Beam line RPL
position 20
BLM
position 08
Beam line RPL
position 20
BLM
position 08
Particle shower more important upstream the quadrupole..?
Because there is a ‘’no magnet space’’ before the quadrupoles…
But is the radiation significantly higher there ?
Double check with radiation survey measurements !

14. Other monitoring systems
RadMon
Data to be received
At extraction LSS2…( At beam level ..?)
100 Gy to 140 Gy/ month
1 kGy/year to 1,5 kGy/year
RadFet ?
BatMons ?
Other than dose
BCT (Beam current transformers, for beam intensity measurement)
Radiation survey

15. Current situation in SPS

16. RPL and BLM since LS1 – Doses 2014+2015

17. RPL and BLM - Yearly dose since LS1
Beam level monitors only

18. SPS Intensity In SPS, dose proportional to beam intensity.
RP data from MSWG presentation
R2E data from R2E injector chain website
: Intensity higher due to CNGS operation
In the following, RP data is used
Year
From RP
From R2E
Difference
2009
4.45E+19
2010
49.71E+18
5.54E+19
5.69E+18
2011
54.87E+18
5.79E+19
3.03E+18
2012
48.72E+18
4.87E+19
-2E+16
2013 (1.5 months of operation before LS1)
5.54E+16
5.35E+16
-1.9E+15
2014
3.4E+18
3.44E+18
4E+16
2015
17.6E+18

19. Comparison BLM 2014 / 2015 - Doses/part
From BLM data, it seem ok to consider that 2014 and 2015 were similar in terms of dose / particles…
Then ok to use data for both RPL and BLM

20. RPL and BLM since LS1 Doses/part for period 2014+2015
Assuming constant dose / particle
Assessing the accelerated particles for the coming years
Estimate the dose in the future
But : How to know the intensity in the future years ??

21. Scaling with distance

22. SPS Tunnel cross section
Installation zone of
foreseen systems
SPS beam line
≈ 150 cm
≈ 175 cm
Tray RPL
≈ 100 cm
≈ 30 cm
Decrease factor at the transport wall and at the ceiling considered to be the same (?)
Coil RPL
And BLM

23. Scaling with distance from beam line
TID
Fluency
/ 4,5
/ 10
/ 4,5
/ 10
From CERN-ACC-NOTE

24. BLM and RPL in SPS ring Cable tray RPL position 08 Cable tray RPL
Beam line RPL
position 20
BLM
position 08
Beam line RPL
position 20
BLM
position 08

25. Scaling with distance from beam line
Comparison of the data from the RPL at the coils and the RPL at the trays
Average 2011 / 2013 is 25
Average 2014 / 2015 is 30
RPL at coils are position 20
RPL at trays are position 08
Data not reliable !

26. BLM and RPL in SPS ring Cable tray RPL position 08 Cable tray RPL
Beam line RPL
position 20
BLM
position 08
Beam line RPL
position 20
BLM
position 08

27. Scaling with distance from beam line
Comparison of the data from the BLM and the RPL at the trays
Average value is 18 (dose from LS1)
Data can de considered as reliable ?
Although the data from two different systems are compared (BLM / RPL) ?

28. Scaling with distance from the beam line
First step: determination of a single scaling factor…
In reality, the scaling factor strongly depends on the exact position, of the specific element at that position..!
Info already available for Points 1, 5 and 7 ?
BLM / RPL data :
Mean factor ʺbeam -> cable tray ʺ is 18
Ranging from 0.1 to 500…
In the following, decrease factor of 10
As advised by MC WG
Considered to be ʺworst caseʺ condition
Open questions
Is this the same decrease factor in the ARCs and in the LSSs ??
For both the transport side wall and the ceiling

29. Yearly dose since LS1
At beam level

30. Yearly dose since LS1
Estimated, at transport wall

31. The future

32. Option 1 : Rough estimate
Assuming
1 MGy/year at the maximum in the SPS (LSS2)
2014 / 2015 data is 520 kGy max at beam level
Then, factor decrease of 10 at ceiling / transport side wall :
100 kGy/year
Conservative scaling with time (Long shutdowns not taken in account !) :
5 years 500kGy
10 years 1 MGy
20 years 2 MGy
40 years 4 MGy
But is dose expected to increase ? -> Option 2
Global increase over the years ?
Specific increase in some areas ?

33. What will influence the dose ?
Intensity : In SPS, dose proportional to intensity
In areas where the losses are dominated by the beam/gas interaction only ! (?)
ARCs only ?
LINAC4 will increase intensity in SPS for HL-LHC purposes
From MC WG : by a factor 4 ?
From LINAC4 project website :
‘’ The new LINAC is expected to increase the beam brightness out of the PSB by a factor of 2’’
SPS for HL-LHC
Now : 1,2E+11 protons/ bunch, 144 bunches
HL-LHC : 2,5E+11 protons / bunch, 288 bunches (Increase of a factor 4 !)
HL-LHC: expected losses in SPS is 10 % (in intensity ?)
But (from James Ridewood, feedback from losses SPS WG)
Dose used to be proportional to intensity, now saturates after a certain intensity due to optics modification / improvement.

34. What will influence the dose ?
Beam dump
Moved out of LSS1 : Dose expected to decrease
How much ?
Moved to the LSS5 (ECA5), with an heavy shielding :
Is dose expected to increase a little or not at all ?
High Energy Hadrons fluence in ECA 5 ~1e5 HEH/cm2/yr (close to ground level 1-2e5 HEH/cm2/yr)
Worst case scenario: Full beam loss at high intensity

35. What will influence the dose ?
SHIP experiment in North area (extraction line LSS2)
Increase of the dose expected due to slow extraction.
ʺAn increase in the intensity for the slow “dirty” extraction as would be used for SHIP might be more consequential for dose rates than the foreseen increase in bunch intensities for LHC….but I might be wrong’’
Injected / extracted intensity depends from the user.
LHC is ‘’peanuts’’, North area is responsible for more radiations !
CRAB cavities in SPS 6
Influence is too low for specific material damage
The issue concerns staff safety only…
New collimator system
Foreseen during LS2, in the aim of reducing the losses
The losses at the collimator ? Everywhere else ?
In which location ?

36. Option 2 : Best case / Worst case
Influence on dose
Best case
Worst case
Intensity increase
(LINAC4, HL-LHC)
Everywhere ? in the Arcs only ?
x ?
SHIP
in LSS2 : x ?
Beam dump
in LSS1 : x ?
in LSS5 : x ?
In LSS5 : x ?
New collimator
Where ? : x ?
Crab cavities
in LSS6 : x ?
TOTAL
Arcs x ?
LSS x ?
LSS x ?
LSS x ?
LSS x ?
LSS x ?
LSS x ?
Increase in intensity is unknown
Influence of modification / upgrade of the machine on the dose is unknown
Increase factors are not know !

37. Predicting the future ?
Input from SLA WG (SPS losses and activation working group) ?
Event ʺFollow-up of general radiation increase in the SPS ʺ (October 2015):
ʺThere are been an increase of the dose per accelerated proton in between 2012 / 2015 ʺ
ʺFactor 5 in activation in 2015 is real (two independent measurements): ~3 from intensity, ~1.5 from specific losses ʺ
Input from RP (Julia Trummer, Helmut Vincke) ?
Inputs from OP (James Ridewood, Karel Cornelis) ?
Need a crystal ball ?

38. Option 3 : Linear Scaling with time

39. 5 years at beam level

40. 10 years at beam level

41. 20 years at beam level

42. 40 years at beam level

43. 1 year at transport wall

44. 5 years at transport wall

45. 10 years at transport wall

46. 20 years at transport wall

47. 40 years at transport wall

48. Estimated accumulated doses at transport wall
Area
Dose / year
5 years dose
10 years dose
20 years dose
40 years dose
Arcs
Below 200 Gy
800 Gy in Arc1+
1 kGy
4 kGy
2 kGy
8 kGy
16 kGy
32 kGy
LSS1
10 kGy
50 kGy
100 kGy
200 kGy
400 kGy
LSS2
55 kGy
275 kGy
550 kGy
1,1 MGy
2,2 MGy
LSS3
300 Gy
1,5 kGy
3 kGy
6 kGy
12 kGy
LSS4
125 Gy
625 Gy
1,25 kGy
2,5 kGy
5 kGy
LSS5
350 Gy
1,75 kGy
3,5 kGy
7 kGy
14 kGy
LSS6
175 Gy
875 Gy
Crab cavities study (LSS6) :
250 Gy/year at beam pipe ?
25 Gy/ year on the floor ?
RadMon in LSS2
1 kGy/year to 1,5 kGy/year ?

49. Proposal for irradiation test dose steps
Area
Dose / year
5 years dose
10 years dose
20 years dose
40 years dose
Arcs
Below 200 Gy
800 Gy in Arc1+
1 kGy
4 kGy
2 kGy
8 kGy
16 kGy
32 kGy
LSS1
10 kGy
50 kGy
100 kGy
200 kGy
400 kGy
LSS2
55 kGy
275 kGy
550 kGy
1,1 MGy
2,2 MGy
LSS3
300 Gy
1,5 kGy
3 kGy
6 kGy
12 kGy
LSS4
125 Gy
625 Gy
1,25 kGy
2,5 kGy
5 kGy
LSS5
350 Gy
1,75 kGy
3,5 kGy
7 kGy
14 kGy
LSS6
175 Gy
875 Gy
2 kGy, 10 kGy, 50 kGy, 500 kGy, 1 MGy, 3 MGy

50. Still open questions Radiation levels in the TAs, at both levels ?
Installation of RadFets or BatMons in TA2 ?
Would require at least one year of integration !
In PA6 for Crab cavities : 1 Gy/year
Radiation levels in the shafts
Fabrice Malacrida contacted -> Not suitable !
Possibility of installing RadFets ?
Fire doors positions
Shall get back when the exact position is defined
Or give inputs so that the doors are not placed at worst positions
Some LSS limits seems to accumulated quite high radiation levels !

51. Thanks for your attention !

52. Radiation survey

53. SPS Schedule Use of 2014 +2015 data for BLM and for RPL ?
LS1 : SPS shut down from Feb.2013 up to Feb.2014
During LS1, some SPS elements were changed or moved, leading to a modification of the machine performance (beam optics modified), etc…
After LS1, BE-OP tuned the magnets, leading to a different beam optics than before LS1.
Dose monitoring data
BLM data is yearly
RPL data is for two years (ex together)
Data before 2014 not considered in this study because machine optic / performance was modified since then
Best to use only 2015 data since optimum machine stings after first months after LS1?
Use of 2015 data for BLM and ( )/2 for RPL ?
Use of data for all dose monitoring systems ?
Use of data for BLM and for RPL ?

54. SPS Geometry SPS geometry 6 sextants of 1152 m
With 36 periods of 32 meters
2 periods = 1 cell (QF-MBA-MBA-MBB-MBB-QD-MBB-MBB-MBA-MBA)
Periods divided in 100 elements numbers
6910 meters in total
BLM positions given in sextant, period, element
Idem for RPL
Transformed in meters for plotting
Similar as DCUM in LHC, but not existent for SPS

55. SPS areas LSS1 Beam dump Injection from PS with TT10 LSS2
Extraction to North area with TT20
LSS3
LSS4
Extraction to LHC or CNGS / AWAKE with TT40
LSS5
LSS6
Extraction to LHC or HiRadMat with TT60