[FS] Coherent Innova 90-MK Krypton Ion-Laser Head
Hi Everyone,
I'm desperately short on space and looking to get rid of my large Innova 90-MK head.
It's a krypton gas laser head and it's the medical version (which I *think* only means it has slightly better beam characteristics).
The head is close to Oxford, and you'd need a car with a long boot or a people-carrier to collect it.
The tube has an igniter and filament transformer with it, so to make it ionise you'd only need a current-regulated power supply that could do close to 300 volts DC at up to 40 amps.
This tube has the magnet in series with the ion tube so you don't need a separate magnet supply.
You'd also need mains water or a closed-loop chiller for cooling.
The ion tube isn't aligned within the resonator frame so that needs doing, Sam's Laser FAQ has details on how to do this via a few different methods.
The lines are (taken from an online reference):
676.4
647.1
530.9
With most of the power on the 647.1nm line, there are a couple of other lines but with no significant power.
The head is gas-tight and I have run it pulsed and got purple flashes out of it, and glow-discharge where it glows pale green for some reason.
The magnet has continuity and seems to be water-tight.
The cathode has continuity and glows orange at ~30A, there is no evidence of sagging.
Mirrors have some small marks on them but nothing that should affect operation to any large degree.
The Brewsters' are chipped on their edges (well out of the beam) but I don't think that makes any odds.
The igniter is present and very definitely works.
I have wound an enormous filament transformer that will be capable of being run center-tapped without saturating.
The high-current pulse discharge was with rectified mains so 310V'ish, although it fired without needing the cap bank fully charged so it isn't quite that high.
As the pressure will now have increased from being stored a stock I-90 power supply (230VDC nominal output) will have serious trouble maintaining a continuous discharge in the tube which is probably somewhere about 280VDC by now.
A power supply that can do a higher voltage than the stock I-90 supply will have no trouble with the tube, but it means you have to know what you're doing in building/acquiring a supply or adapting one from another ion laser.
I've been told that once the tube is running at a decent power level the gas will get buried and the discharge voltage will drop back towards it's rated value again (although this sounds like a very slow process).
It has a fill system and pressure gauge attached, so in the worst case you could use a vacuum pump attached to the fill system to re-gas the head.
Some pictures of the head (note it's now back on it's original aluminium channel that is twice the width and much thicker, the smaller channel would be included if you wanted it):
I acquired the laser with a view to designing an SMPS to power it as my Uni dissertation. I designed the supply then ran out of money/time before I had finished the actual build (anybody want some enormous, hideously-expensive, Molypermalloy inductor cores?), so I've sadly never run it.
The previous owner DID run it and some pics are available on his site:
http://www.electricstuff.co.uk/biglaserfun.html
I'm open to any offers at all, but I can't trade it for anything as I'm only selling it to get more space.
Anybody is welcome to come and see it, and if you have a suitable power supply you'd be more than welcome to come and try it on the head.
EDIT:
I've found an information request on another forum that I don't even remember making
http://www.natscience.com/Uwe/Forum....ova-90-krypton
So the discharge characteristics were 35A/258V in 2002 when it was last run CW.
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Originally Posted by MechEng3
