1. Setup of Gain Monitoring System with Mr. Uozumi Kobe Univ. Hiroko Ikeda 18,May 2007

2. STATUS ・ Mr.Uozumi brought 3flat cables (with MPPCs), a circuit for readout, a LED driver, and LEDs (high-functional, and UV). ・ The LED driver, and one of the flat cables had been broken.

3. STATUS ・ Signal from flat cable is integrated by ADC, and number of photons enter each strip is calculated.

4. MPPCs (1600 pixels) Acryl Frame Scintillator strip (1 x 4.5 x 0.3 cm) To trigger reflection, put reflective material on strips. Then, set the acrylic plate covered by the same material on it. And, shade all from light with black sheet. ADC AMP PC

5. EFFORT Ⅰ At first, there was only one hole on the reflective material. Signal was very small, so, in order to observe larger one, cut holes on the center of each strip. Small change observed.

6. Signal was still small. To see much larger signal, make one of holes bigger roughly, and other 2 holes a single one. EFFORT Ⅱ Obvious change observed. Measurement is ongoing in this circumstance now.

7. RESULTS Size and position of hole Distance from LED At least 5 photons reach each strip now. effect on amount of light

8. OUTLOOK ・ Make much more stable structure to get recreativity. ・ Use multi channel amp. ・ Study and compare about material and characteristic of acrylic plate. ・ Examine which effects more on amount of light size or distance of holes ー if size, need to consider effect of cross-talk ・ Reduce LED noise.