Passive base for Hamamatsu R5912
The Passive base for Hamamatsu R5912 is an adaptation of the current Pierre Auger Observatory base designed to work with UB/UUB and Photonis XP1805 photomultiplier. It uses a passive resistive divider coupled with CAEN A7501 HV power supply module. The divider is tapered on the last stages and backed by capacitors.
The interface towards UB/UUB consists of +12V power rail, ±3V3 amplifier supply rails (UB only) and analog control signals
- VMON
- Scaled HV monitor 0 - 5V
- VSET / CDE
- Scaled control voltage 0 - 2.5V
- IMON
- Voltage corresponding to divider current, transimpedance 50kΩ
- TEMP
- Current corresponding to temperature.
Some information can also be found in the slides concerning the base.
Frist Prototype
The prototype base is designed to be easily modifiable to quickly test new ideas, not strictly to be optimal in cost or performance. That can be optimized later.
Note that the prototype base for PEPS (SN: 67517) was specifically modified to work with UB. This means that the negative voltage rail converter is not populated and instead the amplifier module is powered from the ±3V3 present on the UB interface.
| Pin # | Signal | Description |
|---|---|---|
| 1 | NC | No connection |
| 2 | IMON | Divider current monitor |
| 3 | VMON | Voltage monitor 0 - 5V |
| 4 | VSET | Voltage control 0 - 2.5V |
| 5 | +12V | Power rail |
| 6 | +3V3 | Positive opamp rail |
| 7 | -3V3 | Negative opamp rail |
| 8 | GND | Ground |
| 9 | GND | Ground |
Amplifier Module
The amplifier module takes the signal from the selected dynode and amplifies it with gain of about 45 V/V to achieve dynode/anode ration of 32 (the amplified signal from the dynode is 32x signal from the anode). Bandwidth is about 35 MHz, which is sufficiently larger than the 20 MHz anti-aliasing filter present on the UB frontend. The module design also very closely follows the Auger base.
If you encounter any problems, don't hesitate to contact me at [1].
