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The Quantum Physics LS-32 was one of the first affordable HeNe lasers. With a spec'd output power of 2.5 mW TEM00 at 632.8 nm, it was probably intended for educational use.
It had a two-Brewster plasma tube with a heated filament sealed in a heavy aluminum cylinder with mirrors in aluminum holders at each end. It was probably pre-aligned with only minimal adjustments via two sets of 3 set-screws around the perimeter to move the plasma tube laterally by a very small amount, possibly so small that alignment would not be lost. The HR mirror is planar and the OC mirror is probably around 30 cm RoC, though can you believe I haven't measured it precisely. The mirrors appear to be in good condition for what that's worth. ;-)
Of course, after more than 50 years, the tube is almost certainly up to air. The odds of catching sight of a flock of pink flying elephants is orders of magnitude higher. ;-) But unfortunately there doesn't appear to be any easy way disassemble the head even if Quantum Physics still existed and sold replacement tubes. After removing the mirror mounting plates and all visible screws, there seems to be no way to get at the tube assembly. There is only a single set-screw locking the underlying plate in place, which in itself is strange. I even attempted to pull one out with long screws through a thick plate into the threaded holes but it didn't budge. Nor did it unscrew even with a fair amount of torque. But with that single set-screw, threads with adhesive might make sense. I don't want to force anything risking the tube getting broken. If they are locked in place with Epoxy, heating the cylinder might loosen them but that is probably not a realistic option with a heat gun due to its mass. And there is no sign of glue residue.
And a precautionary note for anyone who finds one of these that was stored in a stasis field so it is still usable and would like to set up the head on a tripod: The 1/4-20 mounting hole is not closed-ended. If a long enough screw threaded in too deep, it will go directly through the bore of the plasma tube! ;( ;-)
The power supply is extremely rudimentary. There are a pair of 6.3 V (probably ~1 A) power transformers connected in series for the filament, no doubt because it was easier to fit in two small transformers than one large one. A separate massive transformer provides the high voltage to a bridge rectifier and 2 µF, 3 kV HV filter capacitor.
The PCB has the bridge rectifier made of HUGE discrete 5 kV diodes, a pair of 1.2M ohm 2 W resistors in series as a bleeder for the HV cap (which are of course underated voltage-wise with order of 1 kV or more across each), a 12 ohm adjustable power resistor to trim the the filament current, and a 50K ohm power resistor which is part of the ballast.
For the hot-filament tube, there is no starter.
The toggle switch selects Off, Filament, HV.
On this sample (SN 453), many parts are bad and not all due to age. Aside from the almost certainly dead tube, the HV transformer is shorted, which took out its contact on the power switch and the shell of the HV connector to the laser head is broken in multiple places. The only thing that still works is the pilot light. ;-) And while it is likely the filament transformers are fine, there is absolutely no evidence of light inside the tube, which would indicate the filament is either open or the tube is up to air and it isn't getting hot enough to glow.
Here are some photos: