APD, CSP and T-card Characteristics Toru Sugitate / Hiroshima University for PHOS FEE Review / PRR Meeting in Wuhan, China on May 30/31, 2005

PHOS electronics embedded

PHOS signal processing scheme

PbW0 4 crystal lead-tungstate crystal (PWO) Fluorescence decay-time of around 25ns at the operation point; i.e. -25deg. Inorganic scintillating crystal of 22x22x180 mm 3, corresponding to 20X 0. Emission spectrum has blue(420nm) and green(500nm) components. Light yield of 7-12 pe/MeV for crystals produced in Apatity. Larger LY as cooling down, but increase slower components. High QE in blue, low noise and capacitance, and thin photo-sensor, operational at low temperature and in magnetic field is required.

Silicon avalanche photo diode (APD)

Smaller sensitive area, but 3-4 times higher QE than PMT. Abrupt breakdown at a certain reverse voltage. NB; data are given at 25 deg.

Gain depends on temp and reverse voltage, and higher performance as cooling down. Both the precise temperature and reverse voltage controls are required.

Reality of APD’s (for samples ~ 1800) number of APD Inverse current (nA) at op. voltage number of APD V op. = V V break – V op. = V I dark peaks at 5nA, and mostly below 15nA. Inverse current (nA) voltage difference (V) V break – V op. number of APD Breakdown voltage and Op. voltage at M= inverse voltage (V)

J-FET Sensitivity Rise time Noise (ENC) Output polarity Feedback loop Power dissipation 2SK932 (I DSS rank =23) by SANYO 0.833V/pC ns over full range 200 e e /pF x C in (pF) Positive 100M  // 1pF 64mW & APD: Hamamatsu S8148/S APD preamplifier: Originally designed and built at CCNU & Bergen. Re-designed in 2002 at Hiroshima using components available in Japan. Hiroshima ver.2 is successfully performed in PHOS256 in 2003/04. Minor modification for ver.3 in ,000 of Hiroshima ver.3 has been produced for the first module. C5 only for test 100M  // 1pF

T-card: 8 CSP outputs into single base connector. Originally built at Bergen in Re-deigned at Hiroshima in 2005 to; fit with the new frame design at Sarov, remove a test pulse generator, and remove serial registers R11 to R16 in power lines, since they are on CSP. 10 samples of the new version for testing. Connectors onboard; MOLEX AMP Sarov design

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