TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Thijs Wijnands (CERN TS Department) Challenges Status Future Interfacing with the LHC accelerator

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Outline  Beam losses and radiation levels in the LHC –Beam lost in equipment and material –Operational aspects –Examples : Point 7, IR1 & IR5  Protection, diagnostics –Post Mortem –BCMs, BLMs –Radiation Monitors  Examples –CMS, LHCb –Radiation at CDF

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Reminder  Complexity of the LHC –Small operational margins –Stored energy high (350 MJ per beam) –Small aperture for beams  Beam losses –Only beam dump can stand a full beam dump –A few mJ is sufficient to quench SC magnets (eq. energy of 1000 protons at 7 TeV) –Many radiation sensitive electronic equipment in tunnel (ARCs and DS) and in UX caverns +- 3  ~1.3 mm 56.0 mm Beam in vacuum chamber with beam screen at 7 TeV Courtesy : R. Schmidt (AB-CO)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Beam losses in materials Design approach for material very close to the beam  Proton losses lead to particle cascades in materials  Main concern is radiation induced heat  Simulations to compute the heat deposition  Select appropriate materials that do not melt Vacuum tank with two jaws installed Ex : LHC Phase I collimator Courtesy : R. Assmann & collimation team (AB-ATB)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Beam losses in electronic equipment Design approach for electronic equipment in tunnel/caverns  Proton losses lead to particle cascades in materials  Main concern is ionisation (Single Events, Dose)  Simulations to compute the hadron flux and Dose  Select appropriate electronic components/materials  Use (and test) radiation tolerant designs Antifuse FPGA (Actel A54SX16, A54SX72A) WorldFIP fieldbus communication (MicroFIP CC131) TMR and “command response” SEE free & TID : 120 kRad in LHC Test Area 7000 cards to be installed in the LHC tunnel Ex : Signal Conditioner for Cryogenic instrumentation M. Rodriguez Ruiz (AT-ACR)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Where are the halo particles lost ? LHC aperture  Mechanical aperture : a mech  Protection devices : a prot  Secondary collimators : a sec  Primary collimators : a prim LHC Design : a prim < a sec < a prot < a mech S. Radaelli (AB-ABP)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Operational settings and constraints Consider a ‘trimmed’ (orbit, tune, chromaticity, …) machine :  Pre-set before fill : –Beam intensity –Trigger level BCMs, BLMs –Max. background level  Tunable during fill: –Collimator jaw positions –Local orbit corrections  Diagnostics –beam losses, radiation monitors –luminosity, backgrounds  Adjustable during stop/shutdown –Shielding –Vacuum quality

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg  Modify the collimator setting … … this is a long, lengthy and iterative tuning job ! –Many collimators/beam (54 movable devices = 108 jaws) –Many BLMs (~3500) and radiation monitors (~300) at many locations  Reduce beam intensity … How to reduce radiation in a specific area ? Careful to avoid an immediate beam dump ! Quench SC magnet Radiation damage equipment From : J. Wenninger in Chamonix Workshop 2003

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Performance limitation ? Risk of SC magnet quenchRisk of Radiation Damage Max. loss rate in collimatorLowHigh Min. loss rate in collimatorHighLow

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Example : IR7 – betatron cleaning section  Improved collimator design –Improved tolerance collimators (material, heat, mechanical …) –Increased loss rates in the LSS Pt7 –Higher radiation levels in Pt7  Radiation issues that came up for Point 7: –Activation of air –Radiation damage to signal cables, optical fibres –Radiation damage to electronic equipment (UJ76 and RRs) –High remnant dose rate during maintenance works –…

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg IR7 – radiation levels to equipment 1 year in RR77 : Dose : 1 Gy Neutrons : 1 x 10 9 cm -2 Hadrons : 1 x 10 8 cm -2 1 year in UJ76 : Dose : 1 Gy Neutrons : 5 x 10 9 cm -2 Hadrons : 5 x 10 8 cm -2 P. Collier (AB-OP)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg IR7 – radiation levels on tunnel wall Shielding Chicane Dose Rate [Gy/year] K. Tsoulou (AB-ATB)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg IR7 – optical fibres in “hot zone” in Pt7 Doped a-SiO2 fibres from Draka Compteq Ltd. Optical Fibres in LHC tunnel  Standard Doped a-SiO2 fibres  Ge-doped and Ge-P-doped  Dose rate ~20 kGy/year  600 fibres through IR7 “hot zone”  Total 2000 km/fibres concerned A. Presland (AB-ATB), L. De Jonge (TS-EL)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg IR7 - radiation damage to optical fibres 1 kGy gives 12 dB Attenuation in Ge-doped SM fibres as function of the total accumulated dose (Co-60 source) after a complete annealing at room temperature Radiation hard optical fibres  5 prototype radhard fibres presently produced by DRAKA Ltd  Extensive radiation testing of samples by Fraunhofer Institute in Germany  First results expected on CERN Radiation Day on 29 November 2005 Radiation Damage  Degradation of blowing tubes no measurable effect up to 350 kGy  Attenuation of light may reach limit in ~1 year

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Example : High Luminosity interaction regions High Luminosity interaction points :  Total particle production in IP –Inelastic –Single diffractive [p < acceptance] –Single diffractive [p > acceptance] –Elastic  SD & Elastic come barreling down the beam pipe, along with some inelastic debris  Inelastic on cavern walls Total cross-section 110 mbarns From : M. Lamont, CERN Radiation Workshop 2004

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Beam induced power deposition – UX caverns Installation of main support tube of forward shielding in ATLAS cavern TX1S shielding and TAS Total power in TAS = 270 W Total power produced in IP 1200 W F. Butin (TS-LEA)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Beam induced power deposition – Straight Section Collision Cross- section DestinationPower Inelastic60 mbarnIRs [TAS, triplet, D1, TAN]680 W Single diffractive 2.4 mbarn Dispersion Suppressors in IR [δp,min(0.01) < δp < δp,max(0.25)] 220 W Single diffractive 9.6 mbarnMomentum Cleaning60 W Elastic40 mbarn Betatron Cleaning (plus some  blow-up) 230 W From : M. Lamont, CERN Radiation Workshop 2004

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Radiation in DS and RRs RR 53 or RR13 at 270 meters from IP Reduce risk of radiation damage downstream of DI-TAN area  To avoid quenching of magnets in D2-Q7 region : –TCL.2 collimator in front of D2 (for LHC upgrade) –TCL.5 collimator in front of Q5 (at startup)  To avoid radiation damage to electronics in RR –Staged concrete shielding to reduce contribution from D1-TAN area (8 tonnes !) –Shield between Q5 and TCL.5 to reduce contribution from TCL.5

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Staged concrete shielding to protect RRs Shielding RRs around Pt1&5 J.B. Jeanneret, I. Baishev, LHC-LJ-ES IP1 or IP5 TAN D1

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg meters from IP RR53 with 6 kA & 600 A power converters RR 53 : Dose : < 1 Gy/year Neutrons : 1 x 10 9 cm -2 / year Hadrons : 1 x 10 8 cm -2 / year Power Converters in RR 53 : 6 kA : 13 4 kA: A: A: 18 Total : 47 converters Beam induced power deposition – DS and RRs Courtesy : D. Nisbet (AB-PO)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Performance limitation ? Risk of SC magnet quench & Radiation Damage Detector Background Min. loss rate in LSSLowHigh Max. loss rate in LSSHighLow

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Post Mortem If the dump is triggered by a BLM or the QPS … … that’s can happen - we will just fill again ! But if the dump is triggered by one the experiments … … everyone wants to know what happened !

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Post Mortem Diagnostics  Radiation Monitors close to beam –Time resolution 1 turn (BLM-S), 1 bunch (BCM) –Spatial resolution ~100 BLMs in IR1&5, ~4 BCMs in CMS –WHERE was the beam lost ?  Radiation Monitors at cavern or tunnel wall –Time resolution data at 50 Hz or less –Spatial resolution 300 monitors in LHC tunnel and caverns 25 monitoring boards inside CMS detector – WHERE did the lost beam end up ?

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Monitoring devices for protection  Beam Condition Monitor –Detector protection device –Protection of sub detectors from adverse beam conditions  Beam Loss Monitors –Machine protection device –Avoid quenches of SC magnets Main concern is radiation induced heat Diamond Detectors for the BCM These monitors can trigger the beam dump !! A. McPherson (PH-CMM)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Monitoring Devices for diagnostic purposes  RADMON monitors in tunnel & caverns –Damage to machine equipment –Measure dose and hadron flux at location of equipment  RADMON monitors inside detectors –Damage to (sub) detectors –Measure dose and hadron fluence at location of inner sub-detectors Main concern is radiation damage effects RADMON Monitoring device for tunnel and cavern walls RADMON Monitoring device for CMS RADMON monitors – 2 types C. Pignard (TS-LEA), F. Ravotti (TS-LEA)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg RADMON Monitoring Device for Tunnel & Caverns  Radiation tolerant design (200 Gy)  Remote readout over several km via fieldbus (WorldFIP) at 1 Mbit/s  Up to 50 Hz Measurements of –Dose, Dose rate –1 Mev Eq. Neutrons fluence –Hadron (E>20 MeV) flux and fluence V4.1 Radiation Monitor Development time : 3 years first series in Q4 2005

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Radiation Sensors for RADMON monitors  Dose sensor : RADFET –Trapped charge in gate oxide –  V at constant current proportional to Dose –Low sensitivity to neutrons, high energy hadrons  Hadron sensor : Toshiba TC554001AF –Radiation induced voltage spikes over a reversed biased p-n junction –Number of “0-1 or 1-0” in SRAM direct proportional to the hadron fluence (E> 20 MeV) –Low sensitivity to dose, low energy hadrons  Neutron sensor : SIEMENS BPW34 –Conductivity variation at forward injection –  V at constant current proportional to 1 MeV eq. n –Low sensitivity to dose, high energy hadrons TOSHIBA TC554001AF-70L SIEMENS BPW34RADFETS

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Results SPS campaign LHC Test Facility (TCC2) LHC Radiation Test Facility (TCC2) Dose rate 1 to 20 Gy per day 1 MeV neutrons 8 x cm -2 Gy MeV hadrons 4 x 10 9 cm -2 Gy -1 LHC ARCs Dose rate 10 Gy per year 1 MeV neutrons5 x cm -2 Gy MeV hadrons 3 x 10 9 cm -2 Gy -1

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg RADMON - Hadron flux measurements Cumulative effects :  Sensitivity increased at higher dose (but can be used up to 200 Gy)  Certain bits stuck at “0” after ~160 Gy (but can be annealed out at 100 ºC – 4hrs) SEU cross section :  x cm -2 /bit depending on bias  Identical to neutron cross sections  No latch up 112 Gy160 Gy 60 MeV protons 60 MeV protons at CYCLONE - UCL Louvain la Neuve 60 MeV protons at OPTIS Facility - PSI Villingen

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg RADMON monitors – Dose in SPS target area Manufacturer B RADFET 500 nm Dose measurements : 137 Gy [Si]: RADFET 93 Gy [C 3 H 7 NO 2 ] : Alanine 80Gy [Air]: PMI Ionisation Chamber 102Gy [Air]: FHT191N Ionisation Chamber Remnant dose Rate : ~1000 times less compared to ‘beam on’

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg RADMON Monitors – Hadron Flux in SPS target area SEU counter Toshiba TC554001AF-70L 20 MeV hadrons 1 x 10 9 cm -2 Gy -1 (FLUKA) 20 MeV hadrons2.3 x 10 9 cm -2 Gy -1 (Radiation Monitor) Radiation Monitor Fluence measurements: 20 MeV hadrons 3.1 x cm -2 (SEU Counter) Compare Fluence : Dose ratio with simulations SPS stopped SPS cycle 100 Hz data acquisition ! x 10 10

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Example : CMS caverns and LSS5 UX cavern : ~18 Radiation monitors CMS detector : ~4 BCMs, 4 Radiation monitors Straight sections until RRs 24 Radiation Monitors 64 Beam Loss Monitors

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Example : LHCb cavern and US85 LHCb cavern 5 radiation monitors for cryo plant 4 radiation monitors for equipment US85 UX85 Long Straight sections 23 radiation monitors 58 beam loss monitors A-L Perrot (TS-LEA), G. Corti (PH-LBD)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Example : Radiation in CDF Collision Hall  Low voltage power supply failures –12 power supplies lost in single day (St. Catherine’s Day) –catastrophic component failure –SEE in interface boards  Physics backgrounds –Missing ET distributions –High calorimeter occupancy  Radiation –Detector damage/lifetime  Silicon detector “incidents”/concerns –Beam related failures Initial Operational Problems at Fermilab Acknowledgements : R. Tesarek (FNAL), R. Yarema (FNAL)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg CDF Power Supply Failures antiprotonsprotons Failure Characteristics – Position Dependent – Beam Related – Catastrophic (Single Event Burn Out) – Switching supplies only – Average failure rate ~3/week – Once 12 supplies failed in 1 day Failure Locations SVX ReadoutCOT Readout N S EW SVX Readout COT Readout

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Radiation from backgrounds ? Plug Calorimeter Wall Calorimeter 2” gap torroid steel Gaps in shielding aligned with backgrounds ?

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Radiation from inner triplets ?  Counter measurements showed low beta quads form a line source of charged particles.  Power supply failure analysis shows largest problem on the west (proton) side of the collision hall. antiprotons protons

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg CERN Radiation monitors in CDF (1)  Collaboration with CDF to detect and mitigate radiation damage (in particular Single Event Errors) in electronic equipment in the collision hall FIB boards – see M. STANITZKI Tuesday 10:10 AM

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg CERN Radiation monitors in CDF (2)  Linux gateway connected to backbone  Operational Data made visible via ACNET  4 Monitors taking data every 20 ms  Measurements : –Dose –1 MeV Neutron fluence –Hadron Flux, fluence Linux Gateway RADMON with TLD dosimeters attached for cross check

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Preliminary data from CDF – hadron flux (1) protons antiprotons SEU counts after 7 weeks

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Preliminary data from CDF – hadron flux (2)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Preliminary Data from CDF – Dose (1) protons antiprotons Dose [rad] after 7 weeks

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Preliminary data from CDF – Dose (2)

TS/LEA, CERN, 1211 Geneva 23 Thijs Wijnands TS/LEA/RADLECC Workshop Heidelberg Conclusions  LHC will be “self-limited” –Operational margins small –Stored energy high –A lot of sensitive material & equipment in tunnel/caverns  Operational challenge : distribute beam losses correctly – Avoid quenching magnets (in particular SC magnets close to IP) – Avoid radiation damage (radiation induced heat, radiation effects) – Keep detector backgrounds low  Radiation damage : we are reasonably well prepared –~80% of equipment and material is sufficient radiation tolerant –complete (time & space resolution) monitoring system –procedure to assure radiation tolerance (staged shielding, radtol component database, radtol designing, radiation tests..)