I wrote part of the acquisition system for one day (VME and Igor sides). The background pressure is around 1.2 10^-7 mbar. We now polarized :
- the MCP front side @ -2000V
- the MCP rear side @100V up to 350 V
- the anode @ 700V
The typical voltage vs current is given here with the count rate (gage on)
| U (V apply) | 2100 | 2200 | 2250 | 2300 | 2350 |
|---|
| micro A | 51 | 53 | 55 | 56 | 57 |
| Count rate (kHz) | 0.450 | 5 | 8 | 12 | 20 |
We also monitored the MCP signal with an amplifier and a regular discriminator. Already a 2100V one can reach 5, then 10, 13, 15, 22 kHz. On that side everything looks more or less OK since one can reach the same count rate at the end. The picture is king of strange ???