Progress report on APD

The schematics of Hamamatsu APD circuit. This doesn’t reflect internal elements of different pre-amps, for which output part and load must be modified slightly.

+400V R1 10kOmh incident light

C1 20microF APD, 1 element

Load, 10kOhm

To Pre-amp or oscilloscope

Progress report on APD

This is a data from Gain measurements using the green LED.

The graph on the next slide shows the data obtained in NICADD and data provided by manufacturer.

reading w/light (A)reading - dark (A) S/N relative gainVoltage Used (V)8.73E-09 9.53E-10 8.1596124 1.0 5.38.39E-09 1.09E-09 6.6790416 1.0 50.69.67E-09 1.72E-09 4.6096133 1.0 102.21.05E-08 1.82E-09 4.7803379 1.0 142.52.01E-08 2.68E-09 6.5020155 1.5 199.32.62E-08 3.23E-09 7.1018364 1.9 223.14.31E-08 3.69E-09 10.698304 3.2 253.15.95E-08 3.77E-09 14.800222 4.5 276.99.84E-08 3.80E-09 24.87163 7.5 302.11.13E-07 3.95E-09 27.488165 8.6 311.51.48E-07 4.08E-09 35.108663 11.2 320.21.72E-07 4.01E-09 41.894115 13.2 3302.20E-07 4.02E-09 53.713184 16.9 3403.09E-07 4.06E-09 74.976929 23.8 3503.85E-07 4.23E-09 89.983864 29.4 3605.60E-07 4.21E-09 131.88555 42.9 3696.88E-07 4.58E-09 149.41093 51.4 3769.51E-07 4.52E-09 209.41987 71.4 3811.51E-06 5.01E-09 300.81581 109.6 3891.88E-06 5.14E-09 364.37048 135.1 390.52.45E-06 5.62E-09 434.94252 170.3 3922.73E-06 5.73E-09 474.60835 188.1 3944.08E-06 6.92E-09 588.89668 260.3 3975.94E-06 7.66E-09 774.89234 362.1 3997.13E-06 8.81E-09 808.80876 406.1 4001.14E-05 1.77E-08 646.54191 432.8 401 high noise data point at verge of breakdown

Progress report on APDGain for Hamamatsu APD

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Voltage, V

GA

IN

for 500nm measured for 420nm general data

Progress report on APD

This is a fit to the gain data, done in Origin 6.1 software. Points were fitted into formula:

0 100 200 300 400

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500

Data: Data1_BModel: ExpGrow2 Chi^2/DoF = 53.03717R^2 = 0.99761 y0 0.8539 ±2.98943x0 388.24322 ±--A1 58.09569 ±--t1 39.83523 ±12.6305A2 52.86774 ±--t2 6.59232 ±0.55668

Y A

xis

Titl

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210 t

xx

t

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eAeAyy

Progress report on APD

This is a crosstalk measurement between neighboring APD element.

For signal from LED< equivalent to 800 MIPs, crosstalk is less then 4%-3%, for a real-life signal with maximum of 100 MIPs this number is expected to decrease even further.

fiber is at the corner, at H2 position. Measurements 2.8 3.5 at 401V and amp_signal=16.5V, in H1=4.9mVdone at H1, G1 and G2 positions 3.6 100 at 402V, and amplitude_signal=16.5V in G2=5.1mVchoise of this corner is not random - it is based on the G1 seems to be unaffected by amplitude increase, characteristics of the matrix elements. nor the signal shape could be seen at 401V.. The corner with the best elements was At 402, signal shape appears a bit, but this ischosen (the most sencitive) already at breakdown so the noise spikes

are larger then that.note: noise is: 2.4 mVall measurements in mVall measurements done at 400V unless stated otherwise

test signal for crosstalk28.5hz, 8.91V, 32.2 mikrosec duty

eq signal 900 MIP, 120PE per MIP (QE 80% for APD)eq signal 900 MIP -> 15PE per MIP (QE=10% for PMT)

Progress report on APD

Above are the results of the channel-by-channel test. Red areas indicate the APD elements that have characteristics much worse then the green and yellow ones.

OK, 100mV at 400V, breakdown at 402OK, same OK, same OK, same OK, same OK, same OK, same OK, sameok, 70micrV breakdown on 400ok, breakdown on 398ok, 75mV ok, 100mV at 402V, brakdown at 404ok, 100mV at 401V, brakdown at 403ok, 100mV at 401V, brakdown at 403ok, 100mV at 401V, brakdown at 403ok, 100mV at 401V, brakdown at 40328mV at 396, breakdown at 398V22mV at 396, breakdown at 398V12mV at 395, breakdown at 396V15mV at 394, breakdown at 395V12mV at 392, breakdown at 394V10mV at 390, breakdown at 391V8mV at 390, breakdown at 390V28mV at 396, breakdown at 398Vok, 100mV at 401V, brakdown at 403ok, 100mV at 401V, brakdown at 403ok, 100mV at 401V, brakdown at 403ok, 100mV at 401V, brakdown at 403OK, 100mV at 400V, breakdown at 402OK, 100mV at 399V, breakdown at 401OK, 100mV at 399V, breakdown at 401ok, 70micrV breakdown on 400

eq signal 900 MIP, 120PE per MIP (QE 80% for APD)eq signal 900 MIP -> 15PE per MIP (QE=10% for PMT)

test signal this test28.5hz, 8.91V, 32.2 mikrosec duty

>is good>is usable

Progress report on APD

APD connection circuit is realized and is working Fast measurements of Gain of APD were performed All elements of APD matrix were tested No change in APD temperature was detected during tests Work is ongoing on the second PC board for the second APD Next, pre-amp will be connected and all channels tested Also, there are plans to measure the Gain vs. temperature of APD

Summary