1. Test and status of Silicon Photo Multipliers Kyungpook National University Youngdo Oh 2004/12/28

2. SiPM – Silicon Photo Multiplier SiPM is a Russian invention, reported by Boris Dolgoshein and colleagues at Moscow Engineering and Physics Institute, Lebedev Physical Institute, and Pulsar Enterprise (Moscow). Ref: NIM A 504 (2003) 48 - 52; NIM A 442 (2000) 187-192 SiPM consists of ~10**3 micropixels, size ~30microns, with very thin (0.75 micron) high field depletion layer. What is SiPM ?

3. Pixels are resistively isolated, each working in limited Geiger mode as “binary” devices. The pixels signals are ganged together by aluminum strips and the summed signal is effectively analog, with dynamic range limited by the number of pixels Gain ~10**6Bias voltage ~25V ~ 70V QE < 20% Sees single pe, and resolves adjacent many-pe peaks with low noise Works In high magnetic fields Time resolution ~30ps for 10 pe How does SiPM work ?

4. View of SiPM at KNU (1) Arrived from Japan at October Fabricated at Russia Dimension : 1mm x 1mm, ~1000 pixels

5. View of SiPM at KNU (2) Anode Kathode Pixels Other one

6. SiPM test setup at KNU

7. Blue LED

8. Signal from Tile and trigger 60Hz pulse to turn on LED Signal from Tile ( read by PMT)

9. R&D Plan – What to do and Discussion Continue to test SiPM Gain, Design and fabrication of SiPM cowork with Japan, Russia and other Korean institute or company R&D for better quantum efficiency If we have fabricated sample in next year, that ’ s Great! Readout and DC power module for prototype calorimeter