Coherent cr54 Krypton?

[ltaudi1]

Ok I know everyone is going to say that is too difficult but i was just putting a feeler out as to how possible it is. How possible is if for me to convert this Coherent from argon to krypton. I know it will have to be re-gassed and new len's/mirrors. But the thing is built like a tank and has disconnects for the gas system as you have fill capabilities. I can see the brewsters and it has external optics for adjustment. It would be a fun project if it is possible.

[sugeek]

Ok I know everyone is going to say that is too difficult but i was just putting a feeler out as to how possible it is. How possible is if for me to convert this Coherent from argon to krypton. I know it will have to be re-gassed and new len's/mirrors. But the thing is built like a tank and has disconnects for the gas system as you have fill capabilities. I can see the brewsters and it has external optics for adjustment. It would be a fun project if it is possible.

You can re-gas the laser to krypton, but why not an Argon krypton mix for a white light laser? Yes there may still be power supply issues, but I will leave that information to the experts. Mixedgas can point you to a good resource to re-gas the laser and will probably step in with good advise soon.

-Adam

[ltaudi1]

well I want to go strictly red since I have more than enough 488 to go the distance. But it would be nice to get to white on a few watt scale, since I have lots and lots of blue I want to pump as much red as I can to get close for mixing with my other aragon. I would think It can maybe push a watt or two but I don't know too much about this little guy. I can always dial the 488 down and match it to a good 635 to get a good balance. But I would get far more red than trying to lase a mixed gas tube. Now I could be totally wrong about that but it makes sense in my head.

[LesioQ]

I think Steve should inject a few words here about Supergraphite technology from those years ... unless it was retubed with ceramic tube ...
Piotr.K

[mixedgas]

I think Steve should inject a few words here about Supergraphite technology from those years ... unless it was retubed with ceramic tube ...
Piotr.K

I'm going to assume its graphite for a minute, as it most likely is. if it has been retrofitted with a ceramic tube, this post is irrelevent.

Supergraphite is a sponge. To go purely krypton will require several run and bake sessions. Ie put in new gas, run the laser , rapidly pump out the gas. The seal actuators from cryocorp are still made for getting onto the tank.
You'll always have a trace of argon because of the spongy graphite and the spongy ceramic spacers. They will burn KR much faster then they burn AR,making your color balence always shifting slowly if you whitelight. They also have a tendancy to "burp"old gas back at you until equilibrium is reached sometime down the road.

This is something your only gonna do once or twice. Regularly repumping starts to present problems.


Doing it on a ceramic tube is something I do NOT discuss on forums, and I have the tools to do it. It cost a fortune to learn that, and the sealing tool retails at 3600$.... Doing it on a ceramic tube without the tool results in a dead tube, very fast.

I helped one university guy in Canada redo a argon and a krypton graphite pair about 15 years ago.
He had very good luck with crude equipment.

Are you lucky enough to have one with the TC guage on it?

You need either a cryotrapped roughing pump or a turbo pump, or best yet a ion pump with a turbo,. Properly conditioned sorption pumps are possible as well. And its easy enough to make a sorption pump. And you can do it, provided the tube never sees air. There are a few tricks to it that I wont mention here.


Unless you ship it to Germany to say HB, or the UK to Whatchamcallit if they are still in business, ask yourself this. Which is easier, 200-300$ + shipping from the US to Italy for the valve actuator, or the cost of some 633 nm diodes. Not to mention a 500 psi bottle of krypton at roughly 700$ US. The 1 or 2 litre 50$ neon sign flasks at one to two atmospheres do not have enough KR in them to refill the fill system. Since that is a small laser, your looking at 75 mW of red or 200 mW of whitelight.

SO if you have the resources of a fairly advanced home vacuum lab or a university lab behind you,I'll walk you through it. As far as other common rare gases go, neon lases mainly in the UV and is a triple ion line, meaning you need to drive the tube way too hard, and xenon does not like to lase CWhy itself. krypton is only rarely used in the neon business, and is quite rare to find it off the shelf. Helium does not have a easily lasable cw visible ion line by itself.

The manual is here. http://www.jklasers.com/cr54laser/cr54laser.htm

Steve

[ltaudi1]

Well that is enough to discourage me. Is a tube retrofit possible?

[mixedgas]

Well that is enough to discourage me. Is a tube retrofit possible?

yes, that PSU would run a lexel 85, a 88, a I60 or maybe a I70. That psu was designed by the same gang that did the 88 supply and the lexel 95 supply, its a bit crude in the fact that it doesnt have negitive feedback in the current loop (well, no feedback, no loop....) but it is very similar in size and function to a 85 or 88.

Now you have a nice working argon, and the manual. Enjoy it! btw, I'm curious, what does the pressure gauge read?

Steve

[Laser Ben]

WOW! That laser has the exact same head assembly and resonator frame as the Model 60 YAG laser I got! Did Coherent just slack on the head design?