EXPERIENCE FROM THE INJECTORS, RADIATION LEVELS & DAMAGE J.P. - - PowerPoint PPT Presentation

EXPERIENCE FROM THE INJECTORS, RADIATION LEVELS & DAMAGE

October 14, 2014 R2E & Availability Workshop

J.P. Saraiva (CERN R2E Project)

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 LAYOUT OPERATION CALCULATIONS MONITORING RADIATION LEVELS FUTURE PRESENT PAST

Equipment Owners

Tunnels: 45 km (-27!) + Experimental Areas Intensities, Losses, Where, Why, Ev… Passive, Active Dosimetry… If no data, Benchmark… RADIATION LEVELS – INJECTOR CHAIN ELECTRONICS: BEST LOCATION/SHIELDING…

r2e–injectors.web.cern.ch

RADIATION LEVELS – OVERVIEW

Radiation levels

RADIATION LEVELS – OVERVIEW

R2E

Single

Event Effects R2E Cumula- tive Damage Material Damage

Radiation levels

1 Gy Gy

RADIATION LEVELS – EVOLUTION

• PS:

 Small impact from LHC beams  CT Extraction -> CNGS & SFTPRO Beam Losses distributed in the ring: up to 8% of the total intensity

(The most contributing process for the overall PS activation)

Run 1 (2010-2012)

77% Nominal Peak Luminosity (7.7x1033 cm-2s-1)

Run 2 (2015-2017)

~1 x Nominal Peak Luminosity (1x1034 cm-2s-1)

Run 3 (2019-2021)

2 x LHC Nominal Peak Luminosity

HL-LHC (2024-2026)

5 -> 10 x Nominal Luminosity, 250 -> 300fb-1y-1

• PSB: Magnets realignment campaign
• PS: MT Extraction  Beam losses: 2%

(10-2014: North Area beam (SFTPRO) delivered using CT)

• CNGS
• LINAC 2 -> LINAC 4
• PSB H- injection: 50 -> 160 MeV

(Same impact from low losses @ 160MeV than higher losses @ 50 MeV?)

• PS injection: 1.4 -> 2 GeV

 Smaller beams in transverse dimensions

• Injectors:

 Small impact expected from LHC beams (losses < 5%)  Permanent demand for intensity in- crease from experiments (e.g. ISOLDE) Prompt Dose not expected to increase significantly

 



   



PICK-UP AMPLIFIERS_TT2

e.g., PU pre-amplifiers in TT2 near the vacuum chamber: Average Lifetime of 1 year (~1 kGy/y)

Pre-amps UES208

Radiation kills Electronics

Consequences:

• Operation: lack of information;
• Radiation exposure to replace

broken equipment.

PICK-UP AMPLIFIERS_PS

• J. Belleman

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

Radiation kills Electronics

PICK-UP AMPLIFIERS_PS

10 cm GAP next to the support girder

New electronics (power supplies + amplifiers) installed during LS1: ETL (LEIR), PSB, PS, TT2 Amplifiers must stand as close as possible to the detector (L4: ~8m; circular machines: ~15m) Before LS1: Problems: with the NIM power supplies and the amplifiers.

WIRE GRIDS_PS COMPLEX

WIRE GRIDS_PS

[Gy/y] TID

SEM Grids amplifiers relocated inside the trench during the LS1 Dose reduction up to a factor of 1000

Inside the trench

GRADIENTS_PS

Reduction factor:~10 between Vacuum chamber & Tunnel walls

GRADIENTS_PS

BEST LOCATION IN THE PS RING:

~1.5m below the floor (DOSE REDUCTION up to 1000) Pick-Ups pre-amps + SEM Grids amps (LS1) inside the trench



[kGy/y]

[Gy/y]

PS ALCOVES

SS77-78

PS ALCOVES (RF ELECTRONICS)

SS77 SS78

PS ALCOVES (RF ELECTRONICS)

TID [Gy/y]

Significant Radiation Levels in the ALCOVE: TID: ~10 Gy/y HEH: ~1010 cm-2y-1

(With concrete & Fe shielding!)

BEAM DIAGNOSTIC INSTRUMENTATION

Standard (glass) Optical Items (camera lenses, viewports…)

BTP.BTV10 viewport (3 years of operation)

 Get brown under radiation  Light Transmission Loss to the Detector

• S. Burger

S/N degradation:

• Noise : Electronics
• Signal : Optics

UNDER RADIATION:

Quartz materials used to avoid 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

 Complete transition to Solid-State Electronics must occur, soon or later!

CERN-made

• rad. hard camera
• Max. TID:  106

Gy!

Cameras with active components (Max. TID: from 100 to 105 Gy)

• S. Burger

(from internal stocks, e.g. some electronics for electrostatic pick-ups; Beam TV)

INDOOR LOCALIZATION SYSTEM_PSB

Beacons for the TETRA system installed in the Injector Chain during LS1 PS PSB Radiation levels near the tunnel walls, e.g. PSB?

INDOOR LOCALIZATION SYSTEM_PSB

TID [kGy/y] /10 /40 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 FLUKA GEOMETRY:

• F. Torre

INTEGRATION:

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]

• L. Bläckberg

FLUKA geometry

FUTURE WORK – BENCHMARK_PSB

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

FLUKA geometry:

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

(tcool  2 months)

 dependent on the induced activation  BLMs cannot be used (saturation…)

FLUKA calculations - Parameters

Source loss term:

Inelastic nuclear interactions of primary beam particles with residual gas nuclei in the vacuum chamber

PS

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

Radiation Survey

• vs. BLMs (ACEM)

Saturation (8-bit ADC) CT extraction

• S. Gilardoni 2010