argon laser tube of copper?

Hi!!
I'm Davide...
So, I've a littel questio

I want built a little argon ion laser and I want know if I can use Copper
to make the tube of the laser...

thank you bey

delpy93 said:

Hi!!
I'm Davide...
So, I've a littel questio

I want built a little argon ion laser and I want know if I can use Copper
to make the tube of the laser...

thank you bey

Click to expand...

Build an Argon laser? I'm guessing you haven't done any reading here at all have you?

In answer to your question, no you can't.

copper definitely won't work. the plasma discharge in an argon laser is hotter than the surface of the sun, so there are only a few substances that can handle it. BeO (Beryllium Oxide) ceramic is the standard material for constructing an argon laser bore, but it is highly toxic if damaged and the powder becomes airborne.. Not something for the timid, or for someone without a multi-million dollar laser manufacturing facility to do..

delpy93 said:

Hi!!
I'm Davide...
So, I've a littel questio

I want built a little argon ion laser and I want know if I can use Copper
to make the tube of the laser...

thank you bey

Click to expand...

He has definitely read loads around the forum (not),

I suggest if you want to even begin making an argon, you research heavily into safety procedures as the voltage the PSU produces is enough to stop your heart. Next read up a lot on how to build the power supply, then read around 200 pages + gain around 2 years experience with crafting, creating and testing tubes.

Then you might stand a chance

It can be done using thin glass tubes, see sam´s laser faq on "typical homemade argon laser"

However do do this you must have extensive glassworking skills and the right equipment not to mention vacuum and gas filling equipment.

Experimentonomen said:

It can be done using thin glass tubes, see sam´s laser faq on "typical homemade argon laser"

However do do this you must have extensive glassworking skills and the right equipment not to mention vacuum and gas filling equipment.

Click to expand...

I would love for you to link me to this.

mfo: check the link in my sig.. the part experimentonomen is talking about is in the table of contents.

Also, a homebuilt all-glass argon could only be run pulsed, with a low repetition rate due to the intense heat of the discharge.

Don't forget this tiny detail:

copper is electrically conductive

I can understand someone having the feeling of accomplishment building something like this but that is one hell of a goal to set yourself. But, learning comes from experimenting so if you have the time, money, patience and perseverance, go for it. My hat comes off for you if you succeed. Edison did say “Genius is 1% inspiration and 99% perspiration!”.

My advice: build a N2 laser first, just to get into it. Then build an even better N2 laser that can run on different gasses, and then start at the difficult gas lasers. A ceramic bore also is possible, but I have no idea if this can be homemade. Just start out with glass and run it only seconds at a time.

Bluefan said:

My advice: build a N2 laser first, just to get into it. Then build an even better N2 laser that can run on different gasses, and then start at the difficult gas lasers. A ceramic bore also is possible, but I have no idea if this can be homemade. Just start out with glass and run it only seconds at a time.

Click to expand...

If you must use a metal for the bore, use stacked aluminum disks and and oxidize them. The AL oxide does not conduct, but you need a huge number of disks. The disks are then stacked in a water cooled alumina ceramic tube. That has been done, but they are hard to start.

A more modern tube is a set of copper disks mounted about 1/4" apart with a tungsten core brazed to the disk, the copper does the cooling, and the tungsten holds off the plasma. The copper disks have folds in them to spread the stress to the outer ceramic tube.

Your talking a excitation 350 to 1000 watts per centimeter of length for a modern CW argon. Pulsing makes use of duty cycle to allow the heat to escape.

The easiest home made argon that could run CW would be a quartz tube with graphite disks. The graphite heats to glowing hot and the cooling is by radiative heat into the cooling water around the tube. If you don't care about lifetime, the earliest argons were quartz bores, but the quartz dies very quickly and its hard to seal the cathode lead throughs direct to quartz.

A pulsed home made argon is possible. Pulsed Oxygen is a MUCH better candidate for a visible laser as is pulsed iodine vapor.


See:

:: Pulslaser ::


Sam's Laser FAQ - Home-Built Pulsed Multiple Gas (PMG) Laser

A Cold Cathode Pulsed Gas Laser" by R. K. Lomnes and J. C. W. Taylor in: Review of Scientific Instruments, vol 42, no. 6, June, 1971

The Scientific American Helium-Mercury design works, but your talking about 15 mW of average power.

I'd strongly suggest you read Lomnes and Taylor before starting any pulsed or cw gas laser construction.

This is lot of work. I've repumped and rebuilt existing tubes and its NOT easy, start with a N2 laser, then a N2 pumped dye laser, and work your way up. To really ARGON work CW you need a lathe, maybe a tig welder, and a turbo-pump roughing pump combination. I have a 270 litre per second ion pump, a turbo pump and two roughers and it can take me 24-48 hours to get to the level of vacuum needed for a cw ion laser, to process the cathodes. Pulsed lasers are far less stringent, you only need to get to .01 or .001 torr, I need to hit 10 to the minus 7 torr, minimum.

But a warning, a fingerprint or other crud in the wrong place inside the tube and your effort is wasted with argon.

Yes, welding grade argon works OK, sorta. . It works great for pulsed duty, but any oxygen or nitrogen or water vapor kills cw lasing. My rare gasses are about 700$ a bottle for CW grade gas. The difference is they bake out the tanks and purge them for scientific grade. Welding grade tanks are not flushed or baked, are often rusty on the inside, and who knows what was in them, before they repainted them for argon use. Helium, however, is reasonably pure from cheap tanks.

And yes, JDSU/uniphase makes their tube's main body from a copper alloy, with ceramic parts brazed in, but glass to metal and ceramic to metal seals are very tricky.

If you really want the details, a Air Force technical report by Bridges and Halstad gives the details of 4 early tube designs, but its 140$ for a hard copy and is NOT available as a free pdf. I have it. It would be hard for a non US citizen to get it.

One of these days I'll rewrite the PMG chapter and send it to Sam, but for now, its fairly correct.

Steve

I am sure that when we wanted to go to the moon people laughed and said like that won't happen. I think it is great that you want to build an argon and I say go for it. I have a CR 15 Coherent and a Spectra Physics with a broken tube, I WILL get them to work again no matter what people tell me. I think Sams FAQ is a great place to look and search. there are tons of reading. What I love about Sam FAQ isthat it is simple and not cluttered with graphics and time consuming loads for fancy backgrounds. It is easy to navigate and search. Another great bore material is graphite and much less toxic than BeO bore materials.

scoobydoo6v92 said:

I am sure that when we wanted to go to the moon people laughed and said like that won't happen.

Click to expand...

Completely different issue?

For one thing, no one had actually gone too the moon so it seemed stupid.

Here people have already built argons and know how they work, realize how ridiculously intricate and how much patience time and money is needed not to mention experience and knowledge.


The fact that the guy asked if it could be made out of copper was obvious he had no idea, and had done no reading so it's not like we're laughing at the idea of someone building an argon, just commenting on the fact you cant just decide you want too build one.

I'd suggest first reading up on how they actually work.

I know,, just that one poster always has a negative spin on things. I know how they work and I don't have the patience or the desire to build my own from scratch. I know that it is a hard daunting task. but with enough fortitude effort and reading i feel it can be done. I have been laughed at wanting to rebuild my CR 15. but God wasn't going to drop a new or a rebuilt one for that matter out of the sky,, I can't affford Evergreed's prices for a tube, so I am in the same boat that the OP is, How can I do it. I was just telling the OP don't let negativity spoil your dreams.

scoobydoo6v92 said:

I know,, just that one poster always has a negative spin on things. I know how they work and I don't have the patience or the desire to build my own from scratch. I know that it is a hard daunting task. but with enough fortitude effort and reading i feel it can be done. I have been laughed at wanting to rebuild my CR 15. but God wasn't going to drop a new or a rebuilt one for that matter out of the sky,, I can't affford Evergreed's prices for a tube, so I am in the same boat that the OP is, How can I do it. I was just telling the OP don't let negativity spoil your dreams.

Click to expand...

I understand where your coming from, and you obviously have the desire and will too rebuild it... And like I said with research and a lot of effort it can be done.

I wish you all the best and look forward from hearing from you when you complete it

Other then the fact that quartz is a real witch to work with in a home lab (needs oxy-hydrogen flame) Whats wrong with the CR?

Pictures? I can quickly tell you a lot about CRs, but I need some images...

Whats broke on the SP?

I've helped one fellow repump a CR once, its a bit involved...

Steve