SVXII Laser test page
We tested the readout system at Kyoto Univ. of education using laser diode which is a junk part of a CD drive. We also tested by using infra red LED.
- Laser diode test result. Sensor is small angle stereo SDC type. In the pside, one coupling capaciter is broken. Beside the Black hole, there are two hot channels on p-side. Bias(90V) is feed from n-side.
- Channel distribution. Sensor is shone from nside. Y-axis is ADC count. Upper side figures are given by pulsing 2 micro sec. ~3V pulse. Upper left is p-side. Broad bump is seen. Upper right is n-side. Narrow signal is seen. Lower side figures are given by pulsing 200 n sec. ~6V pulse. Lower left is p-side. Broad dip is seen. Upper right is n-side. Nothing can be seen.
- Channel distribution. Sensor is shone from pside. Y-axis is ADC count. Upper side figures are given by pulsing 2 micro sec. ~3V pulse. Upper left is p-side. Norrow peak is seen between the black hole and hot channel. Upper right is n-side. Nothing can be seen. Lower side figures are given by pulsing 200 n sec. ~6V pulse. Lower left is p-side. Strange shape bump is seen. Upper right is n-side. Broad bump can be seen.
- Infra red LED result
- Channel distribution. Sensor is shone from nside. Y-axis is ADC count. Left figure is p-side. Right figure is n-side. The wave lenght is around 950nm. There was no bias voltage dependence with ADC counts.