Single shot test beam at PS ! Simulation of a beam loss!

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

2. Can we even imagine a beam „lost“ in IP1 or IP5? Some LHC numbers • Proton energy 7 TeV • Particles per bunch 1011 • Number of bunches 2835 • Stored beam energy 336 MJ • Beam current 0.5 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 imagine a dump failure? General Tracker Meeting 07/2002 Frank Hartmann

3. LHC layout and hint for beamloss reason IP5 • 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 IP6 !!DUMP near to IP5 (CMS)!! General Tracker Meeting 07/2002 Frank Hartmann

4. ! RA EPAC02 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!!??!! General Tracker Meeting 07/2002 Frank Hartmann

5. 8cm Beam conditions at the PS cut • Fast extraction => spill ~ 100 ns duration • Up to 1011 protons per spill(109 to 1010/ 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 General Tracker Meeting 07/2002 Frank Hartmann

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

7. THE WHY!?! • No integral effect expected (worst case = 10 days) • But large instantaneous ionization! 1011MIPS • Will our modules survive a beamloss? • Is our design robust? • Simple YES/NO test! • What is the dynamic behaviour? • Possible failure analysis! ALL PARAMETERS will be dynamically checked slow (10µs) and fast (50ns) (Scopes/FADCs) General Tracker Meeting 07/2002 Frank Hartmann

8. Specific Questions • Will the hybrid survive? • ..............sensor survive? • ..........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? General Tracker Meeting 07/2002 Frank Hartmann

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

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

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

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

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

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

15. Strip parameters Single strip current measurement Scope (measure I) Scope (measure V) Voltage over SiO2 to estimate pinhole development General Tracker Meeting 07/2002 Frank Hartmann

16. Test on hybrid (bare and on module) Parameters: • V250: 2.5V hybrid supply voltage • I250 • V125: 1.25 supply voltage • I125 = 4 parameters (measured with scopes) • (voltages refer to hybrid ground level) • Readout • Standard: APV: Noise, ped, calib General Tracker Meeting 07/2002 Frank Hartmann

17. Readout in situ (APV,module) • Use own Karlsruhe CMS-like readout system (good knowledge of the software) • Prequalification with normal procedures: pedestal, noise, common mode, calibration, LED, laser? • 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 • Later: full qualification (noise,ped,calib,LED)! General Tracker Meeting 07/2002 Frank Hartmann

18. Module parameters • all hybrid parameters • HV + Ileak • 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! General Tracker Meeting 07/2002 Frank Hartmann

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

20. One shot schedule Possible time slots Duration =8 hours (max) 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) General Tracker Meeting 07/2002 Frank Hartmann

21. 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 1011 protons several times varying the bias voltage! • We are aware that the existing program is veryambitious 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 General Tracker Meeting 07/2002 Frank Hartmann