Radiation monitoring and follow up during LHC commissioning Presented by T. Wijnands (TS/LEA) Contributions : SC/RP, AB-ATB, CMS BRM group, speakers at the 6th LHC Radiation workshop All proposals presented here are open for debate !

Outline Radmon for equipment groups Radiation Monitoring (including Radmon) for LHC commissioning 5 March 2008 ELTC days

RADMON radiation monitors T. Wijnands, C. Pignard, D. McFarlane, A. Nyul, A. Prevenas (2 FTEs + 2 Technical Students) CERN, TS Department 5 March 2008 ELTC days

RadMon Radiation Monitors 350 RadMon devices in LHC tunnel, underground areas, caverns To measure radiation levels at the location of equipment on line To check radiation levels against simulations To verify performance of equipment under irradiation To provide early warnings and feedback to EICs in case of danger 5 March 2008 ELTC days

RadMon devices Integrated radiation sensors – 200 Gy Remote radiation sensors – 200 kGy 5 March 2008 ELTC days

Radmon system Tunnel Monitors are all installed and commissioned CMS, ATLAS, CNGS installations before “summer” 2008 Standard AB/CO controls infrastructure Fixed displays (equip monitor) PM Timing TIMBER, METER for logging ROOT Expert program In CCC : Dose rate (dose) Hadron flux (fluence) 1 MeV neutron fluence We are very confident that all this will work because it did so in the SPS (3 years), CDF-Tevatron (1 year), CNGS, Proton Test beams, Neutron test beams, Nuclear reactors, Gamma sources …. 5 March 2008 ELTC days

TSL :174 MeV Neutron Irradiation LHC BLM chamber RADMON D. Kramer, M. Stockner, C. Pignard, T. Wijnands 5 March 2008 ELTC days

Example SPS : high radiation along M2 beam line Bending Magnet M2 beam line wrong 5 March 2008 ELTC days

Outline Radmon for equipment groups Radiation Monitoring (including Radmon) for LHC commissioning 5 March 2008 ELTC days

LHC Radiation Monitoring systems Several systems, various groups, different objectives : RAMSES BLMs Radmons Passive dosimetry BCM/BSC (experiments) See presentations in 6th LHC radiation workshop : http://indico.cern.ch/conferenceDisplay.py?confId=20366 5 March 2008 ELTC days

Radiation measurements at startup We prefer a joined approach for LHC radiation issues : global rather then individual solutions share experience in the field share shiftwork increase measurement resolution shorter turnaround time in case of radiation problems Discussed with D. Forkel-Wirth, S. Roesler, H. Vincke, A. Ferrari, R. Hall Wilton, … 5 March 2008 ELTC days

How to get organized ? Front Office Back Office LHC Operations 1 x EIC with experience in radiation matters 1 x Radiation expert Front Office Simulations Shielding and Monitoring MC Simulations Shielding Analysis Radiation data Modify monitoring Feedback to EICs Radiation Damage Effects Performance equipment under radiation Radtol equipment designs Radiation Tests New System architectures Back Office 5 March 2008 ELTC days

When do we care about radiation in the CCC ? In general : Increase in beam intensity Optics change Change in energy Collisions Phase Description Radiation Areas to check A.1 Injection and first turn yes UJ88, UJ22, UA87, UA23 A.2 Circulating pilot no ARC, UX45, IR7 A.3 450 GeV initial commissioning UA67, UA63, UP62, UP68 A.4 450 GeV optics ARC, DS A.5 Increasing intensity Help ! A.6 2 beam operation - colliding beams at 450 GeV LSS1, LSS5, RRs, UX15, UXC55 A.7 Snap-back and ramp IR3 A.8 Bringing beams into collision A.9 7 TeV optics A.10 Squeeze LSS, RRs A.11 Physics runs UJ14, UJ16, UJ53, UJ57 5 March 2008 ELTC days

What can go wrong ? measured > or < expected No further increase in beam intensity Try to find and eliminate the cause in CCC Inform equipments groups concerned Monitor error rates in equipment Perform detailed (MC) analysis (to be able to compare simulations & measurements) Improve local radiation monitoring Slowly further increase beam intensity measured >> or << expected This may halt the LHC for several months (i.e CNGS) ! Find the cause Design shielding and/or change equipment architecture 5 March 2008 ELTC days

Example : beam on TI8 TED UA Shielding TI8 TED UX85 UJ88 Simulation by H. Vincke SC/RP 5 March 2008 ELTC days

Radiation measurements at end TI8 UJ88 TI8 4R8 UA87 UJ88 UA87 Next to TDI 5 March 2008 ELTC days

TI8 Radiation measurements 4 x 72 x 3e10 on TI8 TED Few tens of counts on Radmons in UJ88 (nbr 8,7,6) Nothing (?) on Radmons in UA87 (nbr 5,4,3) IAMs for integrated dose (< 1 rad) BLMs for loss patterns (spatial & temporal) What can go wrong ? Few 106 hadrons above 20 MeV in UA87 What to do ? Reinforce UA87 shielding Fill up all holes Perform MC simulations Modify radiation monitoring Study equipment failures 5 March 2008 ELTC days

Summary Recommend to use available Radiation diagnostics (including Radmons) in LHC operation Combining BLM, RAMSES, Radmon, BCM/BSC, passive measurements will prove beneficial for all concerned So far everyone is willing to contribute but consolidation (i.e. manpower) is required Proposal is to distinguish between: Radiation damage effects Simulation, shielding and data analysis Radiation diagnostician in charge in CCC 5 March 2008 ELTC days

Conclusions Radiation issues in the LHC will much more complex : Large amount of equipment will be exposed Some (electronic) equipment very sensitive MC simulations of the machine are incomplete Locating the radiation source may prove difficult Consequences of damage to equipment considerable We recommend to start now and to put the infrastructure in place : To reduce impact on LHC operations To minimize the problems related to activation What could be done if we start now : Review simulations, assumptions, back up solutions, radtol designs … Improve radiation measurements in critical areas Detailed plan for LHC commissioning phase 5 March 2008 ELTC days