Quality Assurance of HPDs
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Transcript of Quality Assurance of HPDs
Quality Assurance of HPDs
Arjan .H.Heering Rochester, October 20’01
DC measurements-uniformity-bias behavior-HV and gain-leakage current of each pixel
AC measurements -Capacitance and depletion-AC and DC Crosstalk- signal to noise for single p.e.
HPD Quality Assurance
-DEP HV 1 hour under 15 kVleakage currentQuantum efficiency > 11%Pluse shapedark noise spectrum
-Minnesota
-DatabaseAll data from each tube will be accessible through the web
QA flow for each HPD in Minnesota
HV connector and 1Gohm resistor2 weeks of HV testing under 13 KVDEP
Alignment measurement
DC measurements in darkroom
AC measurement in 2 dedicated room
Alignment QA
Custom Alignment ring
FNAL Interface Cart and packaging
Alignment procedure
-We reference the HPD on the ceramic carrier
- All carriers are within 80 microns, square
-we have send go/no go Jigs to DEP (0.003 inch difference)
-we use 3 sizes (0.001 difference) of carriers
- the best fit will be used for alignment measurement
-x ,y , rot offset from normal is measured (+-10micron)
-each HPD get a compensated offset ring for:-size-x-offset-y-offset-rotation offset
-Alignment is measured again before shipment toFNAL
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X-offset in microns
before
after
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Y-offset in microns
before
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01234567
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
Rotation-offset in mrad
before
after
HPD alignment before and after correction(8 tubes corrected)
2002 Test Beam HPDs
Minnesota will send the first production HPDs to FNAL
Delivery:
March 1 : 10 HPDs (HB)April 1: 10 HPDs (HE)May 1: 10 HPDs (HO?)
-Interface Carts Production start 1/1 2002We need the final routing forHE and HB( HO?)
- Cookies and alignment Support plates are already over budgetCan we use production ODUs for HE?