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APD and Electronics Testing. Leon Mualem Univ. of Minnesota October 2, 2003. From Concept…. To Reality. Test Cooling Circuitry, Components, and Capacity. Actual board, powered and cooled to –25C. Fix Some Issues on Rev. A. Bypassing on V ref and V cc. Higher Value Resistors.
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APD and Electronics Testing Leon Mualem Univ. of Minnesota October 2, 2003
Fix Some Issues on Rev. A Bypassing on Vref and Vcc Higher Value Resistors Filter on voltage Regulator
Initial Noise msmt at FNAL with new board • MASDA noise best case expected 330 e- • 15 Channels with reduced noise after fixes. • 4 @ 390e- • 6 @ 420e- • 3 @ 450e- • 2 @ 480e- • Reminder: This is an interim solution, a properly matched front end should get ~250e- according to Tom Zimmerman 18 Meg Ohms 9 Meg Ohms
Noise testing parameters • Maximum bandwidth setting • 21mV/fC gain 300e-/mV • 1mV=1ADC count • Integration Time (SAFT-SBEF) = 2s
Noise Levels on Bare Board W/10pF W/18M W/9M
Issues … • Cooler plate must not be left floating • Electrically connect to board
Future Plans • Measure noise with powered APD • Measure noise with APD vs. Temperature • Gain measurement with Temperature • Measure noise as a function of Tint • Measure LED generated signal • Measure signal from scintillator with trigger • …