SPS dose forecast for foreseen safety installations Elisa Guillermain elisa.guillermain@cern.ch

What is needed and why ?

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

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

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 1529667 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

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 65-100mm max. Branch: Ø 25-32mm max. Sprinkler heads May 2016

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

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

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)

Dose monitoring in SPS

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…

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 2011-2013 From beginning 2011 up to LSI start (mid 02.2013) – 2 years Data 2014-2015 From 02.2014 to 02.2015 -> No ! – Exposed for 2 years ? 1 year ? In the following : Two years data, whole 2014 and whole 2015

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 !

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

Current situation in SPS

RPL and BLM since LS1 – Doses 2014+2015

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

SPS Intensity In SPS, dose proportional to beam intensity. RP data from MSWG 04.03.2016 presentation R2E data from R2E injector chain website 2010-2012 : 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

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 2014+2015 for both RPL and BLM

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 ??

Scaling with distance

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

Scaling with distance from beam line TID Fluency / 4,5 / 10 / 4,5 / 10 From CERN-ACC-NOTE-2015-0042

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

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 !

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

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) ?

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

Yearly dose since LS1 At beam level

Yearly dose since LS1 Estimated, at transport wall

The future

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 ?

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.

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

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 ?

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 ? LSS1 x ? LSS2 x ? LSS3 x ? LSS4 x ? LSS5 x ? LSS6 x ? Increase in intensity is unknown Influence of modification / upgrade of the machine on the dose is unknown Increase factors are not know !

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 ?

Option 3 : Linear Scaling with time

5 years at beam level

10 years at beam level

20 years at beam level

40 years at beam level

1 year at transport wall

5 years at transport wall

10 years at transport wall

20 years at transport wall

40 years at transport wall

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 ?

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

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 !

Thanks for your attention !

Radiation survey

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. 2014+2015 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 (2014+2015)/2 for RPL ? Use of data 2014 + 2015 for all dose monitoring systems ? Use of 2014 +2015 data for BLM and for RPL ?

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

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