Difference between revisions of "Detectors"
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Revision as of 16:44, 7 January 2014
- The detectors are described in the following POLOG Entry:
- The Acrylic Light Guide is 0.125 inch x 1 inch wide x 2 inch long (data sheet: media:Light_Guide.pdf).
- The Plastic Scintillator for the DE detector is an EJ-212 machine finish of the size 1 mm x 1 inch x 1 inch (data sheet: media:EJ-212.pdf).
- The Plastic Scintillator Rod for the E detector is an EJ-200 (data sheet: media:EJ-200.pdf) of the size 3 inch diameter x 2.5 inch long painted with EJ-510 (data sheet: media:EJ-510.pdf) with one end clear.
- The 1-inch PMT is R6427 (media:PMT_R6427.pdf) in an H7415 Assembly.
- The 3-inch PMT is R6091 (media:PMT_R6091.pdf) in an H6559 Assembly.
- ΔE Detector PMT HV:
- E Detector PMT HV:
- ΔE Detector 792 Dual Delay Module (media:792ds.pdf):
- ΔE Detector 705 Octal Discriminator Veto Thresholds (media:705ds.pdf):
- ΔE Detector 715 Constant Fraction Timing Discriminator Thresholds (media:715ds.pdf):
Shaping Delay = 2 ns
- E Detector 715 Constant Fraction Timing Discriminator Thresholds (media:715ds.pdf):
Shaping Delay = 4 ns
Mott Electronics Logic Setup Procedure
The above is what we had in December 2013. Here is my suggestions:
1- Adjust HV such that signals are 200 mV. Last time we did we where shooting for about 150-200 mV. 2- Set E thresholds = 25 mV. 3- Set ΔE thresholds = 25 mV, we can also try 35 mV and 45 mV. 4- Set the Veto thresholds to 450 mV or 600 mV or completely remove the discriminator. Why do we need high thresholds? Now a value of about 185 is too low and may have cut away events. Also now we can do this cut in analysis
The FADC range is 0-500 mV.
- Step 1: E and ΔE signal triggered from the E signal with a trigger threshold of -25 mV. PMT HVs are adjusted such that all signals are -200 mV.
- Step 2: E trigger gate (30 ns) and ΔE trigger gate (5 ns) triggered from E signal (with ΔE delays listed above).