1. 1 HBD Update: DC Meeting June 2006 Thomas K Hemmick for the HBD Crew…

2. 2 Overview of HBD Progress: HBD Prototype Tests: –Excellent Experience; many lessons learned: Install; Cabling; HV; LV; Noise; Gas QA; Gain; Elect; DAQ; LVL-2; Offline; –One Mystery in Data: MIP apparently seen (Forward Bias). Electrons give larger signals (great). All Signals too low…Factor of 6 Mystery. –Learning the surprises now is the PURPOSE of the test… HBD Construction: –HBD #1 nearly complete…Ship next week. –Glove Box installed & Running at Stony Brook.

3. 3 Quick Comments: Installation: smooth…but detector should have “handles” instead of gas pipes for lifting. Cabling: Final cabling plans excellent. (D. Lynch) HV: Continuously at full voltage…never tripped. LV: Fool-proof…low noise means good grounds. Noise: pedestal sigma < 0.5 photo-electrons. Gas QA: Plumbing perfect; detector is ONLY source of contamination…prototype leaks/outgasses some: –20-25 ppm water, 15-20 ppm oxygen; ONLY 3-4 p.e. loss. Gain: 55 Fe source shows published gain. Electronics: Works through Full DAQ. Maybe fastest turn on of new system in PHENIX history?? –A few channels died (while cabling?). Must investigate. DAQ: Reliable. System occasionally needed feeds. LVL-2: SUPERB!! The LVL-2 stream = high purity electrons. Offline: HBD data smoothly included in CNT files…

4. 4 50mV 100mV250 mV 500mV 1000mV 1500mV Calibration: Calibration uses test pulser input of pre-amps read through full electronics chain. Each channel gets gain curve. Online determination shows 0.1 fC/ch. Exactly the same as design value. PadId1 PadId4 PadId5 PadId8

5. 5 Gain of Detector (Hutch Test): 55 Fe source (6 keV X-rays, 109-e’s). Clear peak. Absolute gain can be determined by comparing the signal from pulser (known charge) to 55 Fe. Gain = 1 x 10 4 …exactly consistent with publication. Same pulser that propagated through full chain. 430mV  Gain=1x10 4 Pulser

6. 6 Hadrons and Electrons in Forward Bias Forward bias allows hadrons to make reference signal. MIP apparently seen…electrons give bigger signal. Factor-of-6 Mystery: Calibration says MIP peak should be channel 600 instead of channel 90.

7. 7 Row-Column Correlation “Rows” in phi, “Columns” in Zed. Offline determines predicted location of track. Clear correlation of track projection with struck pad.

8. 8 Forward-1X Gain Reverse-2X GainForward-2X Gain Reverse-1X Gain Electron Hit Finding Electrons are produced in the collision and in the HBD back plane. Should be ~2X as many from behind HBS as in front. In forward and reverse mode electron efficiency roughly right and independent of gain. Forward Reverse

9. 9 HBD In Beam Tests Extremely valuable experience. Detector seems operational and responds differently to hadrons & electrons. Need to complete all data analysis for N0. Factor-of-6 Mystery might be most important discovery (why we did this now). Request for getting HBD “out”: –Return detector to floor (dead turtle position). –Restore to hutch tests. –Main Electronics  Chi.

10. 10 Main HBD 10 days to finish 1 st vessel after PCB. 2nd PCB shipping to WIS now. First Vessel Ships Middle of Next Week. Second Vessel Ships End of June.

11. 11 Glove Box is here and installed. 0.6 ppm water!! Equipping unit for production now. Dry run next week…production after… <1 month per HBD (factor of 2 contingency)

12. 12 Summary Need to finish analysis of all data. Need to understand Factor-of-6. On track for vessel delivery 1 st August (tight but can be done). Pre-amp board needs to be farmed out. FEM Electronics need 3 months after final design (3 weeks from now following post- mortem of dead channels) –End of September… –Not a delay of vessel installation… “May you live in interesting times”. --RFK Chinese Curse(??)