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

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HBD Update:DC Meeting June 2006

Thomas K Hemmickfor the HBD Crew…

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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.

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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: 55Fe 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…

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50mV 100mV 250mV

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

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Gain of Detector (Hutch Test):

• 55Fe source (6 keV X-rays, 109-e’s). Clear peak.• Absolute gain can be determined by comparing the

signal from pulser (known charge) to 55Fe.• Gain = 1 x 104…exactly consistent with publication.• Same pulser that propagated through full chain.

Pad 13 Fe55 Pulse Height Distribution(D V =495 V, DG=+0.5kV/cm )

0

50

100

150

200

250

0 -0.1 -0.2 -0.3 -0.4 -0.5 -0.6 -0.7Pulse Height [V]

Co

un

ts

430mVGain=1x104

Pulser

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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.

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Row-Column Correlation

• “Rows” in phi, “Columns” in Zed.• Offline determines predicted

location of track.• Clear correlation of track

projection with struck pad.

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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

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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.

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Main HBD

• 10 days to finish 1st vessel after PCB.

• 2nd PCB shipping to WIS now.

• First Vessel Ships Middle of Next Week.• Second Vessel Ships End of June.

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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)

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Summary• Need to finish analysis of all data.• Need to understand Factor-of-6.• On track for vessel delivery 1st 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(??)