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Photomultiplier - Cherenkov detector success! - soldering questions

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ChristofferB:
Hey all!

I've just received a big box of photomultiplier tubes, including the one i needed - a large square end-on pmt.

The divider pcb soldered on the back didn't suit my needs, so i removed it, unfortunately one of the spot-welded wires on the pins broke, and i decided (foolishly) to remove the rest.

How do I go about connecting the tube now? see attached.

 -> There are still fragments of wire spot-welded on, so a socket is a no-go.

 -> Soldering that thick of a pin that's feeding through a glass envelope feels a little risky but maybe a copper heat wick near the bottom of the pin would allow careful soldering?

 -> Little two-screw screw terminal blocks might work, they become quite small when the plastic is removed.


Does anyone have any experience on this front? I really don't feel like risking my lovely tube so I'd like to hear your advice before doing anything.

Thanks!
--Chris

jonpaul:
Chris suggest to include photo of entire tube and model number

Typically these unbased tubes need the dedicated divider board, and the tube wire termination is very delicate and easy to crack the dûment seal.

Can you PM me the photo of tye "bigbox", Iam collecting Photomultipliers since 1968

Kind Regards


Jon

Siwastaja:
I would try very sharp, flush side cutters to remove the remains of spot-welded wires. It's likely good for a socket after this, but if not, you can carefully file down the rest (or use sand paper).

ChristofferB:
It's a Photonis XP3392/SP5 - used with gamma cameras and scintillators. The datasheet (http://www.hzcphotonics.com/products/XP3392.pdf) specifies a divider very different from what was installed, but the divider board also had some features i couldn't make out without removing it completely, like an optocoupler to short dynode stages / some preamp stuff.

Board divider was :         K  D1  D2  D3  D4  D5  D6  D7  D8  A
                                      4R   R    R    R    R    R    R    R   0.75R              R=2M

Datasheet reccomend      K  D1  D2  D3  D4  D5  D6  D7  D8  A
                                       2  1.5   1.5  R    R    R    R    R    0.5R         


Aside from the XP3392 I also got 3 Hamamatsu R1594 tubes, which I can't find much info on, and a Hamamatsu R268HA in a peltier cooled housing, complete with divider!

I'm liking the soldering with a copper heatsink option more and more - i'm really not comfortable with the mechanical strain of screwing a grub screw into the pin.

a last idea could be to get individual tube socket pins and push on, but they won't get very far from the spot welds.

--Chris

ChristofferB:

--- Quote from: Siwastaja on February 08, 2020, 01:08:41 pm ---I would try very sharp, flush side cutters to remove the remains of spot-welded wires. It's likely good for a socket after this, but if not, you can carefully file down the rest (or use sand paper).

--- End quote ---

That might be possible, but I'd still need individual pins - the 19 pin pmt socket is pretty exotic.

Edit: Just tried it on two pins, it works but I can hear the vibrations resonating through the entire dynode stack. I'm worried the vibrations might crack a glass seal around a pin. On the other hand, the glass seals protrude almost a centimeter inwards into the tube.

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