DIY copper vapor laser

[kecked]

I must have been incredibly lucky. Once I found caps that could deliver the punch it only took about 3 hours to get the spark gap lined up and make a pulse. It was a big blob 1/2" or so not a dot. So did it truly lase or just make a UV lamp. Not sure and I'm thinking back 35 years.

I did end up using doorbell caps as I scrounged them old tv sets. These then became a tesla coil later. I had some good luck with glass sheet and tinfoil for hv caps in the tesla coils. Wonder if they might work in this application?

What I'd like to see is a HeSe laser doing all 24 lines! It was the cover of the book I got the N2 laser drawing from. Dr. Strong I think was the author.

I found the book!

https://www.amazon.com/Light-Its-Use...tific+american

http://laserstars.org/history/airlaser.gif

[f150trk21]

Planters - I cant seem to envision how your idea of the adjustable rails would look. Are the caps inside the box?

Looks like the doorknob caps would be the most difficult items to find, I only looked briefly on ebay. Also looks like a HVAC vacuum pump would work.

[planters]

If you look at a typical door knob, ceramic cap, you will see threaded male studs or better for this application, threaded female holes. Fabricate rods with each end turned down to a smaller diameter and threaded on each end. Insert one side into the cap, use the larger diameter to sandwich a sealing washer against the outer surface of the acrylic box. Pass the other, threaded end of the rod through clearance holes in the acrylic box. Place springs around these threaded portions before screwing into the rail. Rotate the cap and rod as a unit to compress these springs and move the rail relative to the wall of the box.

[f150trk21]

Thanks Planters, that explains it.

Im going to start shopping for some caps now.

[Draco]

I must have been incredibly lucky. Once I found caps that could deliver the punch it only took about 3 hours to get the spark gap lined up and make a pulse. It was a big blob 1/2" or so not a dot. So did it truly lase or just make a UV lamp. Not sure and I'm thinking back 35 years.

I did end up using doorbell caps as I scrounged them old tv sets. These then became a tesla coil later. I had some good luck with glass sheet and tinfoil for hv caps in the tesla coils. Wonder if they might work in this application?

What I'd like to see is a HeSe laser doing all 24 lines! It was the cover of the book I got the N2 laser drawing from. Dr. Strong I think was the author.

I found the book!

https://www.amazon.com/Light-Its-Use...tific+american

http://laserstars.org/history/airlaser.gif

I have used glass and aluminum foil caps I made for a tesla coil and they worked quite well, much better then ceramic caps, for a tesla coil ceramic caps in my experience overheat and fail, I have not tried the better door knob caps as I was never able to afford the quantity I needed at that time. When I redesigned the tank circuit I used metallized polypropylene caps, Cornell Dubilier, 942 series
http://www.digikey.com/product-detai...164-ND/1929490
I wonder if they would work for this type of supply for a laser if you can't find door knob caps?

[f150trk21]

Doorknobs seem to be a little pricey, even surplus ones off of ebay when you need 10 - 16 of them. I wonder if the foil/polyethylene film caps could be rolled up on each side of the laser to save some space and be more robust, not just laid flat on each side.

[f150trk21]

I quickly drew this in MS Paint. Using Planters idea of adjustable electrodes in an acrylic box with blumlein caps. There will be one adjustment bolt near each end of the box. Hopefully the spring tension creates a good seal and the aluminium angle bar makes good contact with the flat electrode under it. What do ya think?

[planters]

The drawing is useful.

I think there are a couple of issues. The through-bolt will probably seal well enough if you use soft, greased silicone O-rings. The clearance required to allow the bolt to move freely enough in and out might cause some wiggle and this could allow the "L" channel to elevate off the flat conductor. Even a little separation would increase the impedance at that end and this would undermine your ability to balance the resistance along the length. You might find it frustrating to produce a continuous discharge without hot spots.

What about replacing the shorter, vertical sides of the box with aluminum? If they were conductive then the flat caps could be attached to the outside and the electrodes attached to the inside. The springs themselves could act along with the bolts to ensure good conduction. Multiple bolts along the length will allow you to make very fine adjustments in the spacing even if the electrodes were not perfectly straight. Epoxy glued joints would certainly resist the shear loading, but if you have the ability to mill the walls, then notching the sides along their length will allow you to build a box with extremely strong joints. One description of this type of laser recommended using segments of a band saw blade as the electrode, although many have been built using smooth aluminum surfaces.