VEB Robotron “Otto Schön” Dresden was a manufacturer of electronical equipment in east germany (GDR).
The scintillation probe I own was made by that company presumably in the 70s or 80s. It is very large compared to other detectors.
It can be disassembled rather easy. There are only four screws holding everything together. The scintillation crystal can be taken off by removing a large round cap that is threaded on to the front of the device.
Inside there is a beautiful photomultiplier tube, which is coupled to a 45mm NaI(Tl) scintillation crystal by some silicone grease. Surprisingly the silicone grease looked like new at disassembly. But sadly there is a unpretty crack in the crystal just below the glass window.
At the base of the PMT sits a voltage divider with large resistors. What sits behind the voltage divider seems to be a splitter or filter for the high voltage and signal.
M12FS52A Pinout:
Looking at the base of the tube, the Pins are counted clockwise starting with pin 1 which is the one cut off.
1: ic (inner connection)
2: Dynode 1 and Electrode 2
3: Dynode 3
4: Dynode 5
5: Dynode 7
6: Dynode 11
8: ic
9: inner shield
10: Anode
11: ic
12: Dynode 12
13: Dynode 10
14: Dynode 8
15: Dynode 6
16: Dynode 4
17: Dynode 2
18: ic
19: Electrode 1
20: Cathode
The tube seems to have two focussing electrodes which make experiments a lot harder. I will try to figure out how to use them.