What is this?

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James Luck
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What is this?

Post by James Luck » 11 Jul 2020, 00:36

This is one I just found on the webs, I havent a clue what it would take to even start work with one.

Maybe Luuk has seen one before, or can dig something up.

LARGE Bicron 5HW4P/3CL Scintillation Detector Probe W/ BETA DETECTOR
Here's a link:
https://www.ebay.com/itm/324217715048

Its large and cool looking, although I'm more intrested in what crystal or semi conductor it has hidden within. To include size of the d*** thing.

James.
James luck
Chicago Ill, USA.
Hobbyist/ commercial.
Using a Redlen CZT array.
Mostly detection than identification.

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GigaBecquerel
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Re: What is this?

Post by GigaBecquerel » 11 Jul 2020, 00:51

It looks like a big well detector (duh) with a second one to close the hole.
The second detector looks like a regular NaI, but mounted the wrong way round?
I don't know of any application where it would make sense not to put a reflector on scintillator, apart from alpha counting of course.
I'm just not sure why this would be a beta detector, it doesn't really strike me as one with that big crystal...

James Luck
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Joined: 10 Oct 2019, 04:16
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Re: What is this?

Post by James Luck » 11 Jul 2020, 01:09

GigaBecquerel wrote:
11 Jul 2020, 00:51
It looks like a big well detector (duh) with a second one to close the hole.
The second detector looks like a regular NaI, but mounted the wrong way round?
I don't know of any application where it would make sense not to put a reflector on scintillator, apart from alpha counting of course.
I'm just not sure why this would be a beta detector, it doesn't really strike me as one with that big crystal...
One thing I thought of a moment ago, is the size of the thing may be built in sheilding on the detector itself.
From what little I gathered was the big side with the well is a gamma scint, and the other scint the plug that is beta sensitive. For all I know I could be wrong, i havent been able to find much.

It's also not exactly a one off detector for say. The detector definitely was built for one job, but there are multiple being sold by the seller.

James.
James luck
Chicago Ill, USA.
Hobbyist/ commercial.
Using a Redlen CZT array.
Mostly detection than identification.

Mike S
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Joined: 25 Apr 2020, 10:24
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Re: What is this?

Post by Mike S » 11 Jul 2020, 01:31

Yes, the big side is a NaI crystal with a 3" PMT. The small side is a beta detector. I assume you put the sample in the well, put the beta detector on top of the sample, and you collect gamma and beta counts at the same time.

I bought one of of the big well detectors, but it didn't have a beta detector with it (he didn't have any listed with beta detectors at the time). I have a thread about my questions and findings:

viewtopic.php?f=14&t=821
Mike Sullivan
Central Coast of California, USA

James Luck
Posts: 61
Joined: 10 Oct 2019, 04:16
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Re: What is this?

Post by James Luck » 11 Jul 2020, 01:50

Mike S wrote:
11 Jul 2020, 01:31
Yes, the big side is a NaI crystal with a 3" PMT. The small side is a beta detector. I assume you put the sample in the well, put the beta detector on top of the sample, and you collect gamma and beta counts at the same time.

I bought one of of the big well detectors, but it didn't have a beta detector with it (he didn't have any listed with beta detectors at the time). I have a thread about my questions and findings:

viewtopic.php?f=14&t=821
Huh, didnt know you purchased one previously.
So it's a 3x3 crystal, is the well so big because of sheilding? That makes more sense, I would love to pick one up with a beta detector as well. Although that's honestly a weeks pay if I didnt grind my arse off working that week.

I'll be taking a look at your threads, thanks Mike.

James.
James luck
Chicago Ill, USA.
Hobbyist/ commercial.
Using a Redlen CZT array.
Mostly detection than identification.

Mike S
Posts: 82
Joined: 25 Apr 2020, 10:24
Contact:

Re: What is this?

Post by Mike S » 11 Jul 2020, 02:37

James Luck wrote:
11 Jul 2020, 01:50


Huh, didnt know you purchased one previously.
So it's a 3x3 crystal, is the well so big because of sheilding? That makes more sense, I would love to pick one up with a beta detector as well. Although that's honestly a weeks pay if I didnt grind my arse off working that week.

I'll be taking a look at your threads, thanks Mike.

James.
The crystal is 5" diameter and 4" long, there's a undoped NaI light pipe, and the 3" PMT is smaller than the crystal. I don't believe there is any shielding, but I can't confirm that. It did respond well when I added about 12mm of lead around it, and I think if it had built-in shielding I wouldn't have seen as much change.

Mine was cheaper because it didn't come with a beta detector and because I made an offer for a lower price (though he's since lowered his listed price for the NaI detector without betta detector to about what I paid). But yes, it was an expensive item for a hobby. I couldn't resist the absurdity of the size, the mystery, and the hope that it would work well for my typical uses. It's very sensitive at mid and high energy (Cs-137 and K-40 peaks are big), but the response is not great at low energy, so it can't be my "everything" detector. I'm hoping it will work well for detecting environmental Cs-137 in soil samples. If you go through my thread, you will see that mine has some defects, so I can't say if a different one would be better or worse. All in all, I'm not sure I'd buy one again knowing what I know now.

Mike S.
Mike Sullivan
Central Coast of California, USA

James Luck
Posts: 61
Joined: 10 Oct 2019, 04:16
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Re: What is this?

Post by James Luck » 11 Jul 2020, 04:17

Mike S wrote:
11 Jul 2020, 02:37
James Luck wrote:
11 Jul 2020, 01:50


Huh, didnt know you purchased one previously.
So it's a 3x3 crystal, is the well so big because of sheilding? That makes more sense, I would love to pick one up with a beta detector as well. Although that's honestly a weeks pay if I didnt grind my arse off working that week.

I'll be taking a look at your threads, thanks Mike.

James.
The crystal is 5" diameter and 4" long, there's a undoped NaI light pipe, and the 3" PMT is smaller than the crystal. I don't believe there is any shielding, but I can't confirm that. It did respond well when I added about 12mm of lead around it, and I think if it had built-in shielding I wouldn't have seen as much change.

Mine was cheaper because it didn't come with a beta detector and because I made an offer for a lower price (though he's since lowered his listed price for the NaI detector without betta detector to about what I paid). But yes, it was an expensive item for a hobby. I couldn't resist the absurdity of the size, the mystery, and the hope that it would work well for my typical uses. It's very sensitive at mid and high energy (Cs-137 and K-40 peaks are big), but the response is not great at low energy, so it can't be my "everything" detector. I'm hoping it will work well for detecting environmental Cs-137 in soil samples. If you go through my thread, you will see that mine has some defects, so I can't say if a different one would be better or worse. All in all, I'm not sure I'd buy one again knowing what I know now.

Mike S.
I misread your previous message, that's Massive.
Most of what I want to start doing in the hobby was soil sampling. So well type detectors are not a bad idea.

James.
James luck
Chicago Ill, USA.
Hobbyist/ commercial.
Using a Redlen CZT array.
Mostly detection than identification.

Mike S
Posts: 82
Joined: 25 Apr 2020, 10:24
Contact:

Re: What is this?

Post by Mike S » 11 Jul 2020, 08:32

James Luck wrote:
11 Jul 2020, 04:17
I misread your previous message, that's Massive.
Most of what I want to start doing in the hobby was soil sampling. So well type detectors are not a bad idea.

James.
With soil, you could also use a marinelli beaker and a more conventional detector. I was hoping to use this big one for individual Trinitite samples, but the lack of low end response would leave out a lot of interesting peaks.

I'm not sure if your signature is up to date (it shows you have a plastic scintillator), but if you are considering your first spectrometry detector, I definitely wouldn't get this monster. There's much better options. I'm new to this hobby and apparently still making series of bad purchase decisions, but so far, my best detector was the cheapest: a used Bicron 1.5"x2.25" NaI. It doesn't accumulate counts as fast as a larger detector, but it has the narrowest peaks.

Mike S.
Mike Sullivan
Central Coast of California, USA

James Luck
Posts: 61
Joined: 10 Oct 2019, 04:16
Contact:

Re: What is this?

Post by James Luck » 12 Jul 2020, 15:32

Mike S wrote:
11 Jul 2020, 08:32
James Luck wrote:
11 Jul 2020, 04:17
I misread your previous message, that's Massive.
Most of what I want to start doing in the hobby was soil sampling. So well type detectors are not a bad idea.

James.
With soil, you could also use a marinelli beaker and a more conventional detector. I was hoping to use this big one for individual Trinitite samples, but the lack of low end response would leave out a lot of interesting peaks.

I'm not sure if your signature is up to date (it shows you have a plastic scintillator), but if you are considering your first spectrometry detector, I definitely wouldn't get this monster. There's much better options. I'm new to this hobby and apparently still making series of bad purchase decisions, but so far, my best detector was the cheapest: a used Bicron 1.5"x2.25" NaI. It doesn't accumulate counts as fast as a larger detector, but it has the narrowest peaks.

Mike S.
My signature really isnt my spec set up.
I use a 1x1 CsI undopped scintillator for my spectroscopy set. Works good across the range, I havent had issues in low energy counting. Although your sheilding has to be there or your spectrum will be messy to all heck.

Really my signature is my go to kit for finding "spicy" items.

I've made some bad purchases before, and im nit new to detection, but spectroscopy I am. well I'm not to sure if one of the large detectors will be a bad or good idea. So I'll hold off for now.

James.
James luck
Chicago Ill, USA.
Hobbyist/ commercial.
Using a Redlen CZT array.
Mostly detection than identification.

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