1. General Tracker Meeting 07/2002 Frank Hartmann 1 Joint venture of CMS and ATLAS Single shot test beam at PS! Simulation of a beam loss! Joint ad venture of CMS and ATLAS

2. General Tracker Meeting 07/2002 Frank Hartmann Can we imagine a dump failure? Some LHC numbers Proton energy 7 TeV Particles per bunch 10 11 Number of bunches 2835 Stored beam energy336 MJ Beam current0.5 A Failure: magnet quench; power converter fail, etc.  dipole or quadrupol failure  decaying B-field  need to dump Revolution time: 90µs Abort gap: 3,17µs Kicker rise time: 3µs Can we even imagine a beam „ lost“ in IP1 or IP5?

3. General Tracker Meeting 07/2002 Frank Hartmann !!DUMP near to IP5 (CMS)!! Mika Huhtinen: Single module prefire:very unlikely Assumption only one of the 14 abort kicker fires  4*10^13 protons lost in IP 5 Unsynchronized abort: very likely Assumption one of the dump kickers does not hit the abort gab  bunch swept out for ~3µs; some deviated bunches continue in the machine  1*10^12 protons lost in IP 5 MC: STRUCT;MARS;FLUKA IP5 IP6 LHC layout and hint for beamloss reason

4. General Tracker Meeting 07/2002 Frank Hartmann Improbable things are not impossible! Both prefire and unsynchronized accidents happend at the TEVATRON! BUT: Less critical at the TEVATRON! They are improbable at LHC!!??!! ! RA EPAC02

5. General Tracker Meeting 07/2002 Frank Hartmann Beam conditions at the PS 8cm cut Fast extraction => spill ~ 100 ns duration Up to 10 11 protons per spill (10 9 to 10 10 / cm²) 24 GeV protons Beam spot: Starting 2-3cm diameter beam spot, but we expect to be able to tweak the last quadrapole to have cigar shaped beam spot. –We are currently investigating if a 10cm diameter spot possible? Dosimetry to be handled by T7 group (secondary emission counter, gold or nickel foils). beam available for 8 hour shift, installation 1.5 days beam conditions fixed: 26.7.02

6. General Tracker Meeting 07/2002 Frank Hartmann T7 Area

7. General Tracker Meeting 07/2002 Frank Hartmann THE WHY!?! No integral effect expected (worst case = 10 days) But large instantaneous ionization! 10 11 MIPS 1.Will our modules survive a beamloss? –Is our design robust? –Simple YES/NO test! 2.What is the dynamic behaviour? –Possible failure analysis! ALL PARAMETERS will be dynamically checked slow (10µs) and fast (50ns) (Scopes/FADCs)

8. General Tracker Meeting 07/2002 Frank Hartmann Specific Questions 1.Will the hybrid survive? 2...............sensor survive? 3...........complete module survive?  Disentanglement of components!! How many beam losses are digestable? Check for bias voltage dependencies? Which component of the components breaks, if any?

9. General Tracker Meeting 07/2002 Frank Hartmann Setup  cooling box available (-10°C) (thanks to ATLAS)  2 devices per carrier  devices premounted in carrier incl. patch panel

10. General Tracker Meeting 07/2002 Frank Hartmann Carrier 3 ready in KA

11. General Tracker Meeting 07/2002 Frank Hartmann Scenario 1.Place carrier (DUT) in cold box 2.Full characterization in situ 3.SINGLE 100ns beam spill 4.Full characterization in situ 5.2.-4. with different conditions 6.Place new carrier (DUT)...(3 boxes=times).....etc. Full characterization in home lab; hopefully NO failure analysis

12. General Tracker Meeting 07/2002 Frank Hartmann 3 carriers / tests 1 st carrier: HPK-sensor + hybrid (flex) Vbias ramp : one shot per ramp point (0..100V in steps of 20V and 100..400V in 50V-steps) 2 nd carrier: ST-sensor + good TEC module 3 rd carrier: HPK-sensor + KA prototype TEC module (some pinholes, current..) after ~30 consecutive beam dumps: detect if the module is still alive!

13. General Tracker Meeting 07/2002 Frank Hartmann Parameters on sensors Readoutstrips 1.Ionisation: completely destroy field configuration/depletion! 2.Sensor is short circuited!  worst case 400V on CC!! 3.Furtunately the power supplies will not react on that time scale! 4.Still: Dynamics are complicated and we will try to measure them! HV: voltage&current! Voltage over CC: Pinholes? CCbreak>120V (also check for potential on APV) Single strip current! (also check for Rpoly) +400V 0V HV: voltage&current! Single strip current! (also check for Rpoly) Voltage over CC: Pinholes? CCbreak>120V (also check for potential on APV)

14. General Tracker Meeting 07/2002 Frank Hartmann Sensor parameter • HV: bias voltage • I leak : global leakage current • V AC_DC : Voltage between AC and DC-pads of several groups of strips. 2 or 3 groups are planned! • I DC_biasresistor : also done for 2 or 3 groups of strips • I guard : current possibly induced in the guard ring = 9 parameters (3 groups) sensors on PCB (circuit discussed with RH)  all parameters measured with scopes or FADCs

15. General Tracker Meeting 07/2002 Frank Hartmann Strip parameters Single strip current measurement Voltage over SiO 2 to estimate pinhole development Scope (measure I) Scope (measure V)

16. General Tracker Meeting 07/2002 Frank Hartmann Test on hybrid (bare and on module) Parameters: • V 250 : 2.5V hybrid supply voltage • I 250 • V 125 : 1.25 supply voltage • I 125 = 4 parameters (measured with scopes) ( voltages refer to hybrid ground level) Readout • Standard: APV: Noise, ped, calib

17. General Tracker Meeting 07/2002 Frank Hartmann Readout in situ (APV,module) Use own Karlsruhe CMS-like readout system (good knowledge of the software) 1. Prequalification with normal procedures: pedestal, noise, common mode, calibration, LED, laser? 2. TRIGGER: increase of sensor leakage current send APV reset when APV tickmarks are found: send software triggers and search for header monitor baseline behaviour if header is found Laser response? LED response 3. Later: full qualification (noise,ped,calib,LED)!

18. General Tracker Meeting 07/2002 Frank Hartmann Module parameters • all hybrid parameters • HV + I leak • Full readout • LED and perhaps laser response = 6 parameters (measured with scopes) Reminder: one SINGLE shot  full qualification! Carrier 2&3: Sensor+module will sum up to 30 scope channels!

19. General Tracker Meeting 07/2002 Frank Hartmann Readout adventure Readout over 30m of cables! 1.Optical readout: Most promising and probably the only reasonable –Still parts missing –So far NO experience in KA 2.Cat. 7 network cable (needed anyhow for control) (backup 1) 3.PC in the „hot“ area, controlled via LAN (backup2) Cables have to be installed! Power supply combined effort with ATLAS

20. General Tracker Meeting 07/2002 Frank Hartmann Set up of One-shot beam Time required =1.5 days Conditional on successful replacement of PS power supply and re-establishment of slow extraction beam line FIRST 100ns beam extraction ever done at the PS (standard ~ms) Possible time slots Duration =8 hours (max) One shot schedule

21. General Tracker Meeting 07/2002 Frank Hartmann Summary Our electronics plus detectors should be prepared to survive fast pulses with several orders of magnitude higher particle rates than in nominal conditions. We „SHOOT“ a hybrid, 2 modules, 3 sensors with 10 11 protons several times varying the bias voltage! We are aware that the existing program is very ambitious and the available time is tight, therefore help is welcome! Additional ideas/devices like a CCU is feasible, if additional groups join the venture! Scopes still needed! The project is a joint adventure of CMS & ATLAS The LHCC referee welcomes the project