Item from the 3wk bin - radiation detector?

[Peter "Sci" Turpin]

Just got home and looked up what I found in the 3wk bin tonight since it
looked like maybe a photon-counting tube.
From the google results I see it seems to be a gamma-ray scintillation
detector?? Long chromed steel Bicron-branded thing with BNC plugs.

I usually don't pay much mind to where things come from into the 3wk
system, but I really am curious what the history of this particular item is.

(also, what's happened to the 1wk bin of the system?)

[Aden]

There was some junk from the core of a decommissioned nuclear reactor. Much cheaper just to chuck it in the 3 week bin than to get it taken away as nuclear waste.

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[cepm...@yahoo.co.uk]

Peter

I fished this out of the scrap pile at my university in 1996. On finding
at the bottom of a box of goodies the other day I decided that I had
looked after it for long enough and now it is someone else`s turn :)

Phil

--
" et cognoscetis veritatem et veritas liberabit vos. "

[SamLR]

Can someone please add that to my box?* Once PhD is done poking one of these would be a lot of fun :)

Obviously if someone has more immediate use for it please take it :)

Cheers

S

* last time I saw it it was in the first set of shelves as you enter the workshop, labeled "SamLR"

[oliver greenaway]

might even be able to make it go when i get all the radiation measurement and NIM crate set up...

[Peter "Sci" Turpin]

Well I've got it here. Was going to see if it's possible to remove the
cover & check the condition of the tube. I don't hear any glass loose
inside, but there's a big dent in the interface end indicating it's had
an hard impact at some point, so there is the risk that it's UTA.

Gather it uses a 10-stage photomultiplier tube. Surprisingly low voltage
(marked at 750v).

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[David Murphy]

Personally think if anyone can get it working it'd be cool to have hanging on the wall to try measuring the radiation from various things

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[James Mastros]

Ah, that's what it is.  I did have the interface end open t'other day, wondering what it is, and had some difficulty getting it to fit back together.  Don't think the dent is mine.  It looked, er, interesting.  I also think it'd be really cool to have it set up in the space -- preferably on a rotating base, so it can get a circular, or spherical, view of where radiation comes from -- assuming it's as directional as it seems to look like.

[Andrew Back]

On Wednesday, 12 June 2013 12:30:58 UTC+1, Sci wrote:

Well I've got it here. Was going to see if it's possible to remove the
cover & check the condition of the tube. I don't hear any glass loose
inside, but there's a big dent in the interface end indicating it's had
an hard impact at some point, so there is the risk that it's UTA.

You may already know this but worth pointing out that PMTs don't like being exposed to daylight, and if there is a scintillator crystal in front some of these are sealed as they are made from a seriously hygroscopic and/or toxic substance.

 

Gather it uses a 10-stage photomultiplier tube. Surprisingly low voltage
(marked at 750v).

I've got a growing pile of PMTs here and keep meaning to have a go at building a power supply based on a CCFL inverter, e.g:

  http://charliethompson.50megs.com/LowRippleHVsupply.html

Cheers,

Andrew

[oliver greenaway]

for those who don't know/ didn't see my post of a few months back,  I have a project to acquire lots of radiation monitoring equipment like this for space use.  It needs to be ACnoded though and therefore really needs its own area/room.  discussions stalled a bit at that point, though a few suggestions have been made.  We were going to look at the issue when more settled into the new space.

I have ideas of a permanent airborne radionuclide monitoring station.

also, this will not be directional.  you either need massive lead collimator or a fancy (ish) coincidence setup to do directional things

[Peter "Sci" Turpin]

> On Wednesday, 12 June 2013 12:30:58 UTC+1, Sci wrote:
>
> Well I've got it here. Was going to see if it's possible to remove the
> cover & check the condition of the tube. I don't hear any glass loose
> inside, but there's a big dent in the interface end indicating it's had
> an hard impact at some point, so there is the risk that it's UTA.
>
>
> You may already know this but worth pointing out that PMTs don't like
> being exposed to daylight, and if there is a scintillator crystal in
> front some of these are sealed as they are made from a seriously
> hygroscopic and/or toxic substance.

The unit seems fairly sealed. What I presume is a front aperture is
covered by washers and electrical tape. The crystal enclosure appears to
be seized in place and I'm currently unwilling to apply force to it.
More than 2 decades old though, I'm not going to hold out a lot of hope
for it being usable.

I know PMTs don't like being exposed to natural light levels while
running. Funny story I was told while at a job making MCP-based PMTs,
was an overseas customer returning their tube due to it being "broken".
When tested the lab techs found a perfect image of the customer's lab
burnt into the screen.

I was never involved in the production of monolithic anode
photon-counters, but the PMTs I made were fine at natural light-levels
as long as they weren't powered.

>
> Gather it uses a 10-stage photomultiplier tube. Surprisingly low
> voltage
> (marked at 750v).
>
>
> I've got a growing pile of PMTs here and keep meaning to have a go at
> building a power supply based on a CCFL inverter, e.g:
>
> http://charliethompson.50megs.com/LowRippleHVsupply.html

That would certainly be good. Opens up the option for
rebuilding/repairing it or other sensing tubes.

[Peter "Sci" Turpin]

I recall. Radio meterology. Possibly overlapping/combining with the
vacuum physics stuff.
Almost seems like we could use a more generalised blanket group of
simply "Physics"?

[Peter "Sci" Turpin]

If something in the space is putting out enough gamma rays for this to
detect and map at such a distance, I suspect we'd all be dead. :|

On 12/06/2013 13:05, James Mastros wrote:
> Ah, that's what it is. I did have the interface end open t'other day,
> wondering what it is, and had some difficulty getting it to fit back
> together. Don't think the dent is mine. It looked, er, interesting. I
> also think it'd be really cool to have it set up in the space --
> preferably on a rotating base, so it can get a circular, or spherical,
> view of where radiation comes from -- assuming it's as directional as it
> seems to look like.
>
>
> On 12 June 2013 12:31, David Murphy <murphy...@gmail.com

> <mailto:london-hack-space%2Bunsu...@googlegroups.com>.

> For more options, visit https://groups.google.com/groups/opt_out.
>
>
>
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[chrisbob12]

Used to use Hamamatsu PMTs in big industrial laser scanners: variations on reflected and distorted beam, feeding bright field and dark field channels, gave a remarkably detailed picture of defects in glass, coatings and other flat products, e.g.down to about 50 microns on a continuous 4m wide ribbon. Needed a very high quality spinning mirror.