How are the Electrical Connections of a Scintillator Detector Configured?

[Rajini]

Hell all,
I need a help in understanding the electrical connection of a scintillator, a detector for detecting/counting gamma rays. In the back side of the detector there are three connections, 1. a high voltage supply, 2. to amplifier or preamplifier or single channel or multichannel analyzer, and there is 3rd one, which is connected to the electronic instrument (as shown in the attached figure, the instrument I mean is on the right)..Can someone help me what is this 3rd one? Also I am curious to know what is the instrument shown in the left side (with red and black sockets with +24 V, +15 V, etc).
Thanks for your reply, Raj.

 

[gleem]

The single channel or multichannel analyzer is usually the last instrument in a standard detector system. The analyzers may have outputs to transmit their information to a computer or other device. The picture shows two electronic modules which appear custom made . The right side module has unlabled inputs (for digital signals?) not a particularly good practice. The left side appears to have a selection of outputs for various voltages perhaps for controlling other instrumentation. Where did this picture come from.

 

[Rajini]

Hello Gleem,
Thanks for the input. Yes, I guess they are custom made (found in my lab). My question is: I found three terminals on the scintilator detector, 1 for high voltage supply, 2nd is connected to SCA/MCA or any ADC circuit for converting or amplifying the analog pulses to digital ones. I see there another terminal which was connected to the electronic instrument as seen in the right of the above photograph.
In this website http://scionix.nl/ go to 'configurations general' section..There you see the 'top view' in fig. 5.2 and last color photo..You will see three terminals. I just want to know about it.
Thanks for your reply.
Raj.

 

[gleem]

The 12 V input on the PMT base is for a built in preamp. Putting a preamp in the base helps reduce noise on the signal that goes to the main amplifier. The preamp is close to the signal source having short input leads and is effectively shielded so the output to the amp will have reduced noise.

 

[Rajini]

Hello gleem,
may I know about 'S' in that figure?
Cheers, raj.

 

[gleem]

"S" is the signal output from the preamp.

 

[Rajini]

Hello gleem,
thanks again. HV for supplying the high voltage. Suppose if I don't want to use any pre amplifier, how should I connect the PMT to spectroscopy main amplifier? I think I use a BNC cable to connect the 'S' to the 'input' of spectroscopy main amplifier. Is this okay?
Thanks, Raj.

 

[gleem]

I think you want to use the preamp just connect it to the main amp you might have to reduce the gain the the main amp to prevent saturation.