EXPERIENCE FROM THE INJECTORS, RADIATION LEVELS & DAMAGE J.P. Saraiva (CERN R2E Project) October 14, 2014 R2E & Availability Workshop
OUTLINE 1. Radiation Levels – Overview & Expected Evolution 2. Electronic Devices along the Injector Chain 3. FLUKA Calculations 4. Conclusions & Future work
R2E Project – INJECTOR CHAIN REQUESTS Equipment Owners RADIATION LEVELS – INJECTOR CHAIN Intensities, Losses, Tunnels: 45 km (-27!) If no data, Passive, Active Dosimetry… Where, Why, Ev … + Experimental Areas Benchmark… LAYOUT OPERATION MONITORING CALCULATIONS PAST ELECTRONICS: BEST PRESENT RADIATION LEVELS LOCATION/SHIELDING… FUTURE
r2e – injectors.web.cern.ch
RADIATION LEVELS – OVERVIEW Radiation levels
RADIATION LEVELS – OVERVIEW Radiation levels 1 Gy Gy R2E R2E Single Cumula- Material Event tive Damage Effects Damage
RADIATION LEVELS – EVOLUTION Run 1 (2010-2012) Run 2 (2015-2017) 77% Nominal Peak Luminosity (7.7x10 33 cm -2 s -1 ) ~1 x Nominal Peak Luminosity (1x10 34 cm -2 s -1 ) • PS : • PSB : Magnets realignment campaign Small impact from LHC beams • PS : MT Extraction Beam losses: 2% CT Extraction -> CNGS & SFTPRO (10-2014: North Area beam Beam Losses distributed in the ring: (SFTPRO) delivered using CT) up to 8% of the total intensity • CNGS (The most contributing process for the overall PS activation) Run 3 (2019-2021) HL-LHC (2024-2026) 2 x LHC Nominal Peak Luminosity 5 -> 10 x Nominal Luminosity, 250 -> 300fb -1 y -1 • Injectors : • LINAC 2 -> LINAC 4 Small impact expected from LHC • PSB H - injection: 50 -> 160 MeV beams (losses < 5%) (Same impact from low losses @ 160MeV Permanent demand for intensity in- than higher losses @ 50 MeV?) crease from experiments (e.g. ISOLDE) • PS injection: 1.4 -> 2 GeV Prompt Dose not expected to Smaller beams in transverse dimensions increase significantly
PICK-UP AMPLIFIERS_TT2 Pre-amps Radiation kills Electronics e.g., PU pre-amplifiers in TT2 near the vacuum chamber: Average Lifetime of 1 year UES208 (~1 kGy/y) Consequences: - Operation: lack of information; - Radiation exposure to replace broken equipment.
PICK-UP AMPLIFIERS_PS Radiation kills Electronics Prompt dose near the PS vacuum chamber can easily reach tens/hundreds kGy/y Cable capacitance kills the signal Electronics must stand as close as possible to the beam line J. Belleman
PICK-UP AMPLIFIERS_PS 10 cm GAP next to the support girder
WIRE GRIDS_PS COMPLEX Before LS1: Problems: with the NIM power supplies and the amplifiers. Amplifiers must stand as close as possible to the detector (L4: ~8m; circular machines: ~15m) New electronics (power supplies + amplifiers) installed during LS1: ETL (LEIR), PSB, PS, TT2
WIRE GRIDS_PS TID [Gy/y] Dose reduction up to a factor of 1000 Inside the trench SEM Grids amplifiers relocated inside the trench during the LS1
GRADIENTS_PS Reduction factor: ~ 10 between Vacuum chamber & Tunnel walls
GRADIENTS_PS [Gy/y] [kGy/y] BEST LOCATION IN THE PS RING: Pick-Ups pre-amps + ~1.5m below the floor SEM Grids amps (LS1) (DOSE REDUCTION up to 1000) inside the trench
PS ALCOVES SS77-78
PS ALCOVES (RF ELECTRONICS) SS78 SS77
PS ALCOVES (RF ELECTRONICS) TID [Gy/y] Significant Radiation Levels in the ALCOVE: TID: ~10 Gy/y HEH: ~10 10 cm -2 y -1 (With concrete & Fe shielding!)
BEAM DIAGNOSTIC INSTRUMENTATION Standard (glass) Optical Items (camera lenses, viewports…) Get brown under radiation Light Transmission Loss to the Detector UNDER RADIATION: S/N degradation: - Noise : Electronics - Signal : Optics S. Burger Quartz materials used to avoid BTP.BTV10 viewport (3 years of operation) this issue ( Budget Impact)
VACUUM TUBE-BASED ELECTRONICS - Much more radiation-resistant than semiconductors - Obsolete technology / some tubes not produced anymore - Still being used along the Injection Chain (from internal stocks, e.g. some electronics for electrostatic pick-ups; Beam TV) CERN-made rad. hard camera Max. TID: 10 6 Gy! S. Burger Cameras with active components (Max. TID: from 100 to 10 5 Gy) Complete transition to Solid-State Electronics must occur, soon or later!
INDOOR LOCALIZATION SYSTEM_PSB Beacons for the TETRA system installed in the Injector Chain during LS1 Radiation levels near the tunnel walls, e.g. PSB? PSB PS
INDOOR LOCALIZATION SYSTEM_PSB TID [kGy/y] / 40 / 10 Dose Reduction Factors: 40 & 10 Vacuum Chamber -> Tunnel Walls A more radiation tolerant beacon is under development for the Injectors
CONCLUSIONS ELECTRONICS along the Injectors rise constantly; RADIATION -> ELECTRONICS vs. CABLE LENGTH -> SIGNAL; PROMPT DOSE & ACTIVATION along the Injectors not expected to increase significantly for next runs; RADIATION LEVELS : Higher in the Inj. than LHC -> SEE & CUMULATIVE EFFECTS are of Concern: - Equipment Lifetime/Maintenance; - Radiation Exposure to Personnel …
FUTURE WORK – LINAC 4 FLUKA CALCULATIONS RADIATION LEVELS along L4 INTEGRATION: FLUKA GEOMETRY: F. Torre
FUTURE WORK – BENCHMARK_SPS Monitoring vs. FLUKA calculation studies are being carried out for PSB & SPS. - 21 dosimeters installed (08-2014) in 1 semi-period [external + internal walls + vacuum chamber] FLUKA geometry L. Bläckberg
FUTURE WORK – BENCHMARK_PSB FLUKA geometry: Monitoring vs. FLUKA calculation studies are being carried out for PSB & SPS. (first results: end of 2014) - 60 dosimeters installed (04-2014) in Periods 08 & 10 [external + internal walls + vacuum chambers (4 rings)] - PSB FLUKA geometry performed in 07-2014 PSB_Internal wall PSB_External wall
THANKS TO ALL WHO HAVE CONTRIBUTED!! EN – STI / CV / EL, DGS – RP, BE – ABP / OP / BI / RF / CO, GS – ASE, TE – MPE …
BACKUP
FLUKA calculations - Parameters PS Proton beam momentum : 14 GeV/c Beam loss profile : According to the Radiation Survey of 02/2013 (t cool 2 months) dependent on the induced activation BLMs cannot be used (saturation…)
FLUKA calculations - Parameters PS Source loss term: Inelastic nuclear interactions of primary beam particles with residual gas nuclei in the vacuum chamber Source routine: A. Lechner, R. Kwee, “FLUKA source routine for sampling beam- gas interactions”, 2013 Normalization assumptions: Beam losses distributed in the PS : 8% (CT Extraction) Annual beam intensity (2012): 8.2E+19 p Annual intensity of CT extracted beams (2012): 5.4E+19 p
FLUKA calculations - Parameters CT extraction Radiation Survey vs. BLMs (ACEM) Saturation (8-bit ADC) S. Gilardoni 2010
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