This page describes a project to develop an inexpensive programmable high-voltage supply system for PMTs. This is currently generic R&D but may develop into a system used for i.e. Super-Kamiokande or the propose Long Baseline Neutrino Experiment (LBNE) at Homestake.
Target Specifications
(from LBNE requirements document... take with a grain of salt!)
| Voltage Setting | 1500-2500V | 1V steps | Groups of 16 within 300V range |
| Ripple | <100mV at PMT base | ||
| Voltage Readback | |||
| Current Readback |
The proposed PMT for LBNE requires no more than 1800V, so a range of 1500V-1800V is surely adequate. Current requirement is under discussion but likely ~ 100uA per channel.
A modularity of 16 channels with individually adjustable outputs is forseen.
First Prototype
This is a test board to characterize the Pico 12VV2 DC/DC converter. It consists of a two-stage op-amp driver circuit to provide the necessary 0-12V @ 1A maximum input to the Pico, with a choice of feedback options. Voltage may be set by a pot or external signal. An SHV connector for the PMT cable and signal coupling capacitor are provided in case we want to connect an actual PMT.
Candidate Components
- Pico Electronics VV series
- Supertex LR8
- ST micro VB408 (discontinued). See this circuit This is a nice idea, but draws way too much standing current for use as-is.
