Ok, a good friend of mine bought a large amount of gear at auction a few years ago. It came from the closing auction of a Lexel plant. (This is just before Cambridge bought Lexel) A couple of semi trucks worth.
He has 22 some Lexel 85-SVG heads, these are a hotter then normal Lexel 85 with special crystal quartz Brewster windows for higher power. They are rated to do in excess of 450 mW of 514 and 450 mW of 488 plus the other argon lines for more then 8500 hours. Some of these have tested as high as 2.2 watts at rated test current when taken out of the box. A more realistic rating would be 1.5 watts. You will not find the 85-SVG on the Lexel web site, it is a custom head made for semiconductor inspection.
He has at last count 66 of the tubes.
The problem in the past was the large PSU required to make a Argon run was a back breaker. Cheap psus based on resistors with no feedback, while light in weight, had greatly reduced tube life times. With no way to dampen spikes in current and plasma oscillations, the tube life would be shortened.
About two years ago, we came up with a way to kill the oscillations, provide current control, and if the semiconductors failed, the tube would stay lasing on the water cooled resistor, alone. Most times a damaged semiconductor fails shorted. No heavy, back breaking, inductors or boost transformers, either.
So here is the deal, $1100+ proper shipping gets you a working, lasing, head, a spare plasma tube, the critical parts (ie cathode transformer, ignitor, circuit breaker, flow switch, WCR, current sensor) and plans/ some parts for the PSU. You supply the construction labor, as that is what is expensive. He can build one for you, but that drives the cost up.
We're still working on the exact terms, so that is a guideline.
Here is a example unit with the PSU compact enough to be built in the head, yet has full current mode control and the flow switch. To fit it in the head, the resonator was moved over a bit. If your uncomfortable with taking apart a resonator, the PSU can easily go into a small external box.
Requirements: 220-240 V SINGLE PHASE power line, 50 or 60 Hz. 2.2 gallons a minute of cooling water.
What you get, 488, 514, 501, 496, 476, 457, and depending on installed optics/tube current, some other lines.
I'll post measurements from a typical head shortly.
PICs of a the prototype, factory head cover not shown.
Let me know if interested. If you do not feel like building the custom PSU, he has 6 of the classic factory 85 psus, but cost would be higher. Note, within some areas of the US, he delivers as he is often on the road doing repairs. This actually is the preferred method of delivery.
Steve