1. HBD Report Craig Woody BNL DC Meeting January 7, 2009

2. C.Woody, DC Meeting, 1/7/092 All LV, signal, and test pulse cables are connected on both halves of the detector (two uninstrumented sectors are not powered) HV cables are not plugged in waiting for some additional checking of the calibration of the 1471N HV modules in the lab - 5 out of 6 modules were calibrated at UVC, but one (which was in use at Stony Brook) was not; we would like to get this one and two other spares calibrated before the run - New HV program is running on the HV server in CR and is being extensively tested before connecting HV to the HBD Internal RTDs and pressure sensors (for measuring P/T) are connected and are being read out and recorded Heater system is connected but not activated, but could be turned on if we decide we want to use it Electrical

3. C.Woody, DC Meeting, 1/7/093 Preamp cooling system is up and running and thermocouples are being read out to monitor readout board temperatures Preamps and DCMs have been powered up and read out Pedestals have been measured and noise levels look good (a few noisy modules which we will investigate) Will use full 12 sample DCM program for standalone data taking and calibration. Switch to 3 sample program (which Chi will provide) for standard data taking Hall probe sensors for measuring inner magnetic field have arrived and should be installed with a few weeks Electronics

4. C.Woody, DC Meeting, 1/7/094 ADC Pedestal Sigmas Typical Uninstrumented WorstNext worse T.Sakaguchi

5. C.Woody, DC Meeting, 1/7/095 Both halves of the detector are under argon flow at ~ 2.5 lpm. Can increase to ~ 5 lpm during the run. H 2 O and O 2 levels look good as measured by the water and oxygen sensors: ~ 5 ppm O 2 ~ 7 ppm H 2 O Gas transmission monitor is up and running and has been used to measure the gas transparency. However, there is currently a discrepancy between the H 2 O levels as measured by the transmission monitor and the sensors. O 2 levels agree fairly well. Gas System

6. C.Woody, DC Meeting, 1/7/096 H 2 O and O 2 Levels from Sensors O 2 sensors replaced Switched to CF 4

7. C.Woody, DC Meeting, 1/7/097 H 2 O and O 2 Levels from Transmission Monitor (2.5hrs. of flow thru cells) Could we possibly be seeing some other contaminant than H 2 O and O 2 ?

8. C.Woody, DC Meeting, 1/7/098 All GEM modules were tested inside the IR up to 500 V in CF 4 and found to hold voltage the same as at Stony Brook Light sensitivity of the photocathodes was measured inside the IR and no significant change was observed from what was measured at Stony Brook –CF 4 gas flow –Used Scintillation Cube to illuminate small area of photocathode –Used 55 Fe to measure gas gain in same region as PC measurement Detector

9. C.Woody, DC Meeting, 1/7/099 Photocathode Light Sensitivity Test USB PHENIX Fe55 (pad17) Scintillation (pad17) (Trig’d with SBD) Scintillation (pad17) (Trig’d with SBD) Vin=4100V DG: ~1kV/cm Gain~2900 Vin=4000V DG: ~1kV/cm Gain~2400 Npe=4.6 Npe=4.4 DG: = 0 kV/cm (jumper) DG: ~ 0 kV/cm (2 PS’s) West Detector

10. C.Woody, DC Meeting, 1/7/0910 Photocathode Light Sensitivity Test East Detector (no trigger signal from SBD) USB PHENIX Fe55 (pad17) Vin=4000V DG: ~1kV/cm Gain~4600 Fe55 (pad17) Vin=4100V DG: ~1kV/cm Gain~9000 Scintillation (pad17) (Self-Trig’d ) Npe=3.6 DG: ~ 0 kV/cm (2 PS’s) Scintillation (pad17) (Self-Trig’d ) Npe=3.7 DG: ~ 0 kV/cm (2 PS’s)

11. C.Woody, DC Meeting, 1/7/0911 Initial HV settings – HBD West

12. C.Woody, DC Meeting, 1/7/0912 Initial HV settings – HBD East

13. C.Woody, DC Meeting, 1/7/0913 Online calibration is basically ready (based on Run 7) Calibration  setting gain and reverse bias voltage Scan reverse bias voltage for each module to optimize hadron blindness vs photon efficiency (does not require tracking) Use signal from scintillation light to measure gas gain for each pad –Requires tracking (PC1 and DC) to eliminate tail from dE/dx Looking into possibly doing this without tracking but no conclusion yet –Does not require final HBD clustering algorithm. Hub-and-Spoke algorithm is basically working, but will continue to evolve and improve until needed for production With Au+Au in Run 7, gain calibration was done using ~40 CPUs in counting room and ~ 1 TB of disk –Required ~ 5M Au+Au events –Expect to need ~ 50M pp events equivalent Calibration

14. C.Woody, DC Meeting, 1/7/0914 Start flowing CF 4 when shifts start ~ Jan 27 th First collisions ~ Feb 20 th – time in detector Start with moderate gain (~ 2000) and perform series of HV scans to optimize drift gap voltages for all modules –This can be done in standalone mode using only number of pad hits per module (does not require tracking) –Series of short runs (~ 1M events each) with different drift gap voltages at fixed gain Collect large statistics (~ 50M events) to accurately measure gain of each pad using scintillation (requires tracking) Repeat for several gain settings (will use to adjust for P/T variations) Estimated time for all scans and gain calibrations ~ 1 week (or more…) Assume start of physics ~ March 2 th Take data in ± field configuration for 1 week Leave detector in for rest of pp run. Use as an additional Cherenkov counter for high P T electron id Run Scenario

15. C.Woody, DC Meeting, 1/7/0915 Backup Slides

16. C.Woody, DC Meeting, 1/7/0916 ADC Pedestal Means & Sigmas ~ 4 chs ~ 1.4 chs (typ) ~ 5 chs uninstrumented T.Sakaguchi