The ware for January 2009 is shown below. Click on the images for a larger version.
I figured since I was running so far behind on posts that I’d just do two this month to catch myself up.
This ware is a bit of a puzzler that was brought to me by Mike Fitzmorris. I love tubes of all kinds, but this one is a bit of an oddity. I did some googling about and found spec sheets and part numbers for it, so I know what it is but I don’t know what it’s for. In particular, why did the engineers of this tube spend the effort to make the face hexagonal? Seems ideal for tiling in an array of some type, but I can only speculate why. Would love to hear your thoughts!
oh, could it be one of those photomultiplier tube detector?
http://www.photonis.com/upload/industryscience/pdf/pmt/XP3422.PDF ?
(u missed a part no on two photos)
It is a photomultiplier tube, the Philips XP3422
And a typical use is for gamma ray telescopes, apparently. See http://www.dur.ac.uk/~dph0www4/papers/Mark6webversion.pdf for an example. Chapter 4 discusses why they chose this tube and figure 5 shows how the hexagon packing is used.
Indeed, Philips XP3422 PMT. It seems to be for use in Gamma ray cameras, where multiple tubes would indeed be tiled, and hex for better packing.
@jim: it seems they are used only in triggers due to some latency issues (they are slow and nonlinear)
http://arxiv.org/pdf/astro-ph/9804212v1 [pdf] more info about durham mark 6 gamma ray telescope
I don’t even know what could it be …
Ooh, it’s a photomultiplier tube. And it looks like it comes with a power supply, resistor divider chain, and possibly even the amplifier all built into the socket. How convenient!
If you want to try out it, you’ll need to keep it in complete darkness (preferably in a box sealed with optically opaque photo tape) for about a month or so to let it settle down. It’ll easily detect the light coming through a pinhole…
The light through a pinhole may be too much, depending on how high the gain is set. I spent a summer wrapping scintillator blocks with mylar and running linearity tests on PMTs. We had a light-tight box, painted black, lined with black stuff; checked for light leaks by turning the room lights off and seeing if the levels changed. With PMTs you can get a 1-photoelectron response, 1ns rise time, the works. This is one area where solid state hasn’t caught up in performance.
I don’t think you need to put it in a box for a month. If it’s been mistreated (overdriven), the dark current will be all over the place, and you’ll have to let it settle down, under power and in the dark. But if it hasn’t been abused, it should run just fine.
I’m afraid there’s not much you can do with a single PMT. If you had two, you could hook them up to scintillator material and do a muon lifetime measurement. If you had a whole bunch, and the appropriate scintillator material, you could build a gamma ray camera! Or, if you had lead glass, an electromagnetic calorimeter! You see where this is going… all the applications tend to be in particle physics.
Some really big PMTs are used in neutrino telescopes, for > 2pi steradian coverage:
http://www.sno.phy.queensu.ca/sno/images/phototube_support/index.html
http://www.amanda.uci.edu/public_info.html
The Burle PMT handbook covers the concepts in gory detail (180 pages):
http://www.burle.com/cgi-bin/byteserver.pl/pdf/Photo.pdf
I know this is extremely late, but I just found this site…
These are actually also used in the manufacture and design of radiation detectors that use flow cells manufactured from scintillin (sp?)…they’re mainly used to measure two ‘styles’ of radiation in the pharmaceuticals industry. They basically radio tag pills and test them on rats, then use detectors to see where the drugs ended up
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