1. Progress report on APD zThe Gain dependence on temperature measurements were made using a good channel of APD for three temperature values, using LED as source of light. zThe temperature values used were chosen as easily achievable technically and don’t carry any additional importance. zWork on the better APD shielding is (still) in progress. Most dominant noise frequencies have been identified.

2. Progress report on APD zno light, 390V bias voltage. zAt 8.9C zAt 22C

3. Progress report on APD zGreen light, 390V bias voltage. zAt 8.9C zAt 22C

4. Progress report on APD  To compare with works done on the subject: above: left- Dark Current vs. T, right- Gain vs. T., both figures are from the paper: “ Crystal Clear Characterization of arrays of avalanche photodiodes for small animal positron emission tomography”, by J.-B. Mosset, S. Saladino, J.-F. Loude and C. Morel, from PET instrumentation laboratory, Institute for High Energy Physics,University of Lausanne,Switzerland

5. Progress report on APD zAs the device is cooled, high dependence of Gain on temperature is observed. By lowering temperature by about 12C, an increase in the Gain by 2.4 times was achieved. zDark current is also reduced by cooling in 1.5 times zResults are obtained using a higher voltage then in the figures from a paper shown; voltage choice is based upon Gain measurements from previous presentations. zWork on the compact shielding of APD and on the reduction of the high- frequency noise is in progress. Summary