In case anyone in Science is interested in an electronics/science fusion project, there are plans in the current issue of Nuts & Volts for an Arduino-based spectrophotometer. I can lend to anyone interested.
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Cool stuff. Does it give any particulars on spectral resolution, range and detector sensitivity?
The Science Committee has a nice, working spectrophotometer and if you can make the weekly science meeting on Sundays at 2:30 I think it’s likely that one of them would show you how to use it.
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ScienceComm has a spectrophotometer? I don’t see it in the Tools Wiki.
We just happen to need 2 spectrophotometers for the Fusor Project. The 1st will stare at a scintillator element, looking for fluorescence caused by neutron collisions. The 2nd will scan the plasma ball, assaying spectral lines to determine populations of Deuterium, Tritium, H3, and H4.
We have the goodies to make 2 spectrophotometers, with enough sensitivity to hopefully detect the things we’re looking for (I don’t think CCDs or avalanche detectors will fill the bill in this case).
I think old school photomultipliers are called for in this case. They have about 150x the sensitivity of Silicon or Gallium detectors, a good response speed (appr 700 kHz), and a nice wide spectrum.
I can’t believe this stuff is still laying around from the last century…
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Oh buddy, you got some awesome toys! If you/y’all make detectors from these please let me know because I’ve been wanting to show our members what can be done with a Raman spectrophotometer for a long time. I have everything for it except a good detector and expertise in the detector area.
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What do you have, exactly?
Got an enclosed work space ~2x2x1.5ft
532nm 150mw laser
532nm OD6 notch filter
Czerny-turner spectrometer with slit (not shown), mirrors, and grating (not shown)… parts are not in great shape but functioning
Somewhere in Science, there is supposed to exist this:
Yup. It’s a good spectrophotometer for absorption studies.
Not sensitive enough for Raman signals though. About 1 in every 10 million photons of incident radiation on a Raman active sample will produce a Raman signal.
Hahaha. Ok, just help me out a little bit… where does the red wire go?
Any spec sheets?
I’d guess… I’d hope… that if you go looking through the drawers in Science you’ll find the one that the committee has in house. The software for it was installed on the computer.
Why the committee stashes away its only piece of analytical equipment in a drawer instead of having it setup on countertop space? Can you take the blue from the sky? Can you put the wind in your pocket? Can you catch a rainbow? No. Such is Science Committee. 
From personal experience, optics is one of things Russians do well… so that’s a plus.
Cool. I’ll check those numbers, refresh on requirements and play with a translator. Thank goodness for the universality of numbers.
I sent the spec sheets to a Russian friend (yes NSA, a RUSSIAN friend) to translate. I think we need to know what they are telling us, or could tell us back in 1988 in the USSR…
Would you be interested in a spare PM?
Edit: Here are the specs on it from Google. Not sure if it would be useful to you guys or not.
| Specifications | |
|---|---|
| Minimum Wavelength | 300 nm |
| Outside Diameter | 28 mm |
| Peak Wavelength | 420 nm |
| Maximum Wavelength | 650 nm |
| Viewing Direction | Head on |
| Rise Time | 4 ns |
| Photocathode Material | Bialkali |
| Window Material | Borosilicate |
| Anode Current | 0.1 mA |
| Typical Photocathode Luminous Sensitivity [µA/lm] | 95 |
| Photocathode Peak Radiant Sensitivity [A/W] | 0.088 |
| Gain | 2.1 x 106 |
| Max. Supply Voltage Between Anode and Cathode | 1500 VDC |
| Max. Supply Voltage Between Anode and Last Dynode | 250 VDC |
| Operating Temperature | -80 to +50 °C |
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I’m interested but lack the skillz to wire the puppy up. If somebody else cracks it I’d like to test it out. Thank ya Robert!
Sorry for the delay, just saw the message…
That’s a Hamamatsu, they make great stuff!
That’s kind of a weird spec for “Maximum Wavelength: 650 nm”, usually PMTs roll off way into the IR…
I’m confident in proxying for @Josh_Melnick in this matter: yes, we can use a PMT centering at 420 nm in the Fusion Group of Science. That happens to be the emission wavelength of the scintillator we’re building.
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