Search found 39 matches

by Mike S
06 Jul 2020, 08:09
Forum: Spectrum
Topic: Trinitite - 28 Day Gamma Spectrum - To Barium or not to Barium?
Replies: 3
Views: 92

Re: Trinitite - 28 Day Gamma Spectrum - To Barium or not to Barium?

Massimo, I'm a fan of creative thread titles, so I like yours. That is such an interesting and well-prepared spectrum. You clearly put a lot of care and effort into your work. It will be a nice example for me as I continue to learn. I have a piece (from a friend, ID: JC-TR-01 in some of my threads) ...
by Mike S
05 Jul 2020, 05:11
Forum: Detectors
Topic: Liquid Scintillators
Replies: 5
Views: 71

Re: Liquid Scintillators

As a newcomer to this pursuit, I have no information to provide, but as a lover of technical mysteries, I thank you for sharing, and look forward to hearing more as you look for answers.

Mike S.
by Mike S
04 Jul 2020, 08:58
Forum: Detectors
Topic: Is this Detector Too Big, Too Old, or Just Normal?
Replies: 13
Views: 132

Re: Is this Detector Too Big, Too Old, or Just Normal?

Thanks for the help guys! I'm surprised you both don't think the milkiness, cracking, or separation are major issues; it makes me wonder what "bad" looks like. The well appears to be aluminum, it is definitely different than the rest of the housing. It is the smaller diameter (1-3/4") well, which is...
by Mike S
04 Jul 2020, 01:31
Forum: Detectors
Topic: Is this Detector Too Big, Too Old, or Just Normal?
Replies: 13
Views: 132

Re: Is this Detector Too Big, Too Old, or Just Normal?

Hi Mike, Don't worry about the crack that does not have to be a problem, I have repaired detectors with big and many cracks that still work great. The color is difficult to see on the picture but it looks not so bad to be honest. The interface between the crystal and glass looks good to me for an o...
by Mike S
03 Jul 2020, 17:50
Forum: Detectors
Topic: Is this Detector Too Big, Too Old, or Just Normal?
Replies: 13
Views: 132

Re: Is this Detector Too Big, Too Old, or Just Normal?

Thanks for the input guys! It's not looking too good for this crystal... The light pipe looks clear, but things get very milky at the actual crystal. In addition, it appears there a large separation between the light pipe and the crystal (about 15% of the area). This could be a crack but I don't thi...
by Mike S
03 Jul 2020, 11:56
Forum: Detectors
Topic: Is this Detector Too Big, Too Old, or Just Normal?
Replies: 13
Views: 132

Re: Is this Detector Too Big, Too Old, or Just Normal?

Yes, what you are seeing is normal, as the stuff can get very thick over time. Although if you are careful, and the coupling compound is still clean and pliable, you could save and reuse it, but I would recommend replacing it. You'll want to inspect that crystal, and the only way to do that is to s...
by Mike S
03 Jul 2020, 10:03
Forum: Detectors
Topic: Is this Detector Too Big, Too Old, or Just Normal?
Replies: 13
Views: 132

Re: Is this Detector Too Big, Too Old, or Just Normal?

Hi Mike - Next thing to do is to take the PMT housing off of the crystal can (remove the 4 allen head machine screws). The PMT housing should lift up a little bit easy enough, but the PMT may be stuck to the window of the crystal can and might need some persuasion. If they don't come apart easy eno...
by Mike S
03 Jul 2020, 07:36
Forum: Detectors
Topic: Is this Detector Too Big, Too Old, or Just Normal?
Replies: 13
Views: 132

Is this Detector Too Big, Too Old, or Just Normal?

I bought a used 5"x4" detector with an end well, and it seems to at least partially work, but I've noticed some differences compared to the two other detectors I have (an old very used 2x2" and a recently acquired, but also used, 1.5x2.25"). Bicron 5x4 Detector.JPG I'm trying to determine if it's no...
by Mike S
27 Jun 2020, 04:40
Forum: Detectors
Topic: Questions about Voltage Divider PMT bases
Replies: 6
Views: 127

Re: Questions about Voltage Divider PMT bases

3: this question I don’t understand! Luuk Luuk, Thank you for your answers. Question 3 was because I have a detector that has a "G" adjustment potentiometer. I'm assuming it is a gain trimmer, and it does seem to perform that function. My question is why would we want to adjust the gain at the dete...
by Mike S
26 Jun 2020, 17:31
Forum: Detectors
Topic: Questions about Voltage Divider PMT bases
Replies: 6
Views: 127

Questions about Voltage Divider PMT bases

I have not found a good source that explains the basic questions I have about voltage divider bases for PMTs. I'll ask my questions, but if someone just wants to say "go read this and it will explain it", that would also be great. I could not find my answers in Practical Gamma-ray Spectrometry by Gi...