Radiation monitoring: what do we have and what do we need? M. Calviani, M. Brugger, P. Peronnard, J. Saraiva, G. Spiezia (EN/STI) R2E/Availability Workshop October 2014

Summary  Use of the monitoring system  Brief summary of Run I experience  RadMon development  Injectors monitoring  Requirements from users  What would be needed for Run II October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 2

What do we use the monitoring for  Measurement of radiation levels in the machines:  High energy hadron fluence (HEH)  Total ionizing dose (TID) 1.Understanding of the radiation field in the tunnel and shielded areas and support for simulation extrapolation 2.Important service to equipment groups for failure analysis 3.Input/requirement for equipment design October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 3

What would happen if don’t have it  Cannot correlate equipment failure with radiation levels  risk of changing equipment w/o solving the problem  Cannot anticipate need for equipment upgrades – rad-tolerant  Cannot study radiation impact of changing operational parameters  Cannot dissociate the possible radiation source  Limited info on eventual radiation quantity responsible for degradation (TID, NIEL, HEH) October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 4

Types of detectors employed October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 5 RadMons/RadFETs (HEH/cm 2, Gy(SiO2)) Radiation levels close to equipment of interest, non necessary “standard” locations Time profile available Dedicated detectors BLM (Gy – cumulated) Provide loss distribution (dynamic view) Total dose Other detectors with high granularity TLD/HLD (Gy – cumulated) Integral dose at the location of interest Passive dosimetry

LHC RadMon coverage October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 6  LHC  Critical areas (UJ, RR, US, UX, RE, UA)  DS and start of ARC  LSS  Experiments

RadMon locations in DS/ARC October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 7  DS/ARC (from cell 7 to 20)  RadMon are placed below the interconnect between the last MB/MQ of a given cell  Equipment below MB/MQ! MB MQ MB MQMB cell i cell i+1 cell icell i+1  Dedicated LHC-MD  extraction of an operative ratio between BLM dose and expected HEH from RadMons = ~1 SEU count/mGy Tunnel equipment (QPS, CRYO, BLM or EPC)

Experience from Run I (1/5)  Nice summary of Run I observation is available herehere  Radiation levels summarized with the use of different types of detectors (RadMons, BLMs, FGCs, etc.) October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 8

Experience from Run I (2/5)  Lesson:  Important to follow-up machine operational parameters (TCL/RR) October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 9

Experience from Run I (3/5) October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 10  Lessons:  BLM analysis fundamental for the DS/ARC  When BLM/RadMon available, good agreement between them Point 4

Experience from Run I (4/5) October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 11  Very important to follow-up radiation monitoring following operational variations  Sometimes just scaling is risky... Predictions 2012 Observations end 2012 Decreased: TCL closed Increased: tight collimators Increased: higher cum. lumi

Experience from Run I (5/5) October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 12  We should not forget the p-Pb and Pb-Pb runs  Due to the Bound-Free Pair Production (BFPP), even for short runs, radiation levels can be up to 5 times those of a “standard” pp run  DS cells most affected ~7 months ~3 days

Open points in view of Run II October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 13  25 ns operation uncertainties:  Evolution of beam-gas levels during 25 ns operation still to be fully clarified  During Chamonix 2012 it was stated that pressure will not increase more than 2x with respect to 50 ns  However – experience showed that pressure variation depends strongly on real operational parameters Still an open point

Open points in view of Run II  LHC Point 4 and Point 6  UX45: radiation levels in 2012 higher than expected from 2011  triggered TE/CRG relocation activities  How the situation will evolve with 25ns operation?  UX65: still calm, as no special equipment might increase the beam-gas interaction  Monitoring has been improved October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 14

RadMons developments October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 15  During LS1 more than 100 RadMons have been installed in machines  450 in total  Injectors, target area, experimental areas..  LHC: ARC P relocations for R2E  RadMon v5  LHC  RadMon v6  Experimental areas (n_TOF, AD)  Injection lines

RadMons development  Features of v6:  Remote configurability  Self-diagnostic  Radiation resistance 3 times higher  New sensors October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 16  Advantages with respect to v5:  Resolution improved by a factor of 10  Reduced number of tunnel access to change settings  Longer life-time

RadMons development  Overall resolution improvement – factor of 3 to 10  TID limit 3x times larger October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 17 SensorSensitivity *Resolution Range (Prev)(New-V6) Fet rad/mV 300 rad 20 rad 1 Mrad Fet100 Bias 14 rad/mV NA 6 rad 0.4 Mrad BPW (3) 4·10 9 n/cm 2 /mV 3·10 10 n/cm 2 6·10 9 n/cm n/cm 2 BPW (1) 1·10 10 n/cm 2 /mV 7·10 10 n/cm 2 2·10 10 n/cm 2 5·10 14 n/cm 2 Toshiba 2·10 6 n/cm2/count 2·10 8 n/cm 2 2·10 8 n/cm 2 2·10 11 n/cm 2 Cypress 1.5·10 5 (8·10 5 ) n/cm 2 /count NA 1.5·10 7 (8·10 7 ) n/cm 2 4·10 11 n/cm 2

BatMon – versatile instrument October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 18  Where versatile installation is required  E.g. PLC failures in LHC Point 4 and 6 requiring urgent checks 1.Validation of the relocation strategy 2.Measure R-factor in critical area via voltage change 3.Measurement requests for machine studies

Injector’s radiation monitoring  R2E up to 2012 concentrated on the LHC, in order to mitigate radiation effects for Run 1  However issues are present in the injector chain as well, simply “less visible”  In order to guarantee machine availability also in the future, it’s important to dedicate resources on it as well  Info available at injectors.web.cern.ch/ injectors.web.cern.ch/ October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 19

Issues with present radiation monitoring October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 20  BLMs (ACEM – Aluminum Cathode Electron Multipliers)  Saturation in critical areas, of no use for loss distribution  Not calibrated to dose  Ongoing campaign to install LHC-type BLMs in PSB (not PS)  important to be able to evaluate cumulative dose  SPS ionisation chambers – low granularity (1 every 32 meters)  HLD (not online system)  Radiation Surveys  Depends on activation, cannot directly relate to rad levels for equipment

PSB example (RS vs. HLD) October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 21

PS example (RS vs. HLD) October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 22

October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 23

October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 24

Injector monitoring - future October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 25  Requirements:  Appropriate BLM coverage with sufficient granularity in PS/PSB/SPS  RadMon installation extension  Passive dosimetry  Important to follow-up this measurements and improve analysis speed

Requirements from users October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 26  A weekly report was published during 2011/2012, providing radiation levels in critical areas  Service to users in support of the RadWG

Requirements from users October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 27  However:  It was a manual system, requiring full support from the MCWG team  Difficult for users to understand levels if equipment away from the detector location  interpretation/extrapolation from MCWG team needed  Loss scenarios can modify radiation levels distributions  Investment should be made to try to automatize it!

Requirements from users October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 28  An attempt of realizing an online system was performed in collaboration with EN/ICE Dedicated support of EN/ICE requested to revise the system LHC R2E Dashboard  Complex to maintain, since as of now data requires manual manipulation

What will be needed for Run II 1.Reactivation of the MCWG analysis team 2.Dedicated support from the BLM team to provide cumulated doses on a weekly basis 3.RadMon team to continue support the detectors 4.Continue keep track of the detectors inventory (Layout DB?) 5.Support of the groups for fast reporting on equipment failures 6.Continue improving on radiation monitoring in the injectors October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 29

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October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 31 Fundamental to follow-up on these, at the moment done manually!

Conclusions  Monitoring is and will be an important aspects of the R2E (and Availability) activities  In the LHC and in the Injector chain  It is now required as a service rather than studies  Powerful instrument that allow providing a service to equipment owners in understanding radiation-related failures October 2014 M. Calviani: Radiation monitoring - R2E/Availability Workshop 32