Legit Hack Creates TEA Laser Power by Mr. Wimshurst

It’s a bit scary what you can make with stuff found in the average household, provided you know what you’re doing. How about a TEA laser? Don’t have a high-voltage power supply to run it? Do what [Steven] of rimstar.org did, and power it with a homemade Wimshurst machine.

TEA lasers give off ultraviolet light. In order to see the beam, [Steven] aims it through a glass of water tinted with highlighting-marker juice and onto a sheet of white paper. [Steven] originally used his homemade 30kV DC power supply to light up his TEA laser. He made the laser itself from aluminium foil, angled aluminium, transparency sheets, some basic hardware components, and a 100kΩ resistor.

Although the components are simple, adjusting them so that the laser actually works is quite a feat. [Steven] says he burned holes through several transparencies and pieces of foil before getting it right. Using a Wimshurst machine to power the TEA laser takes another level of patience. It takes about 25 cranks of the static electricity-producing machine to build up enough energy to attempt lasing.

Want to make your own TEA laser, perhaps in a different configuration? [Steven]’s design was based on one of [sparkbangbuzz]’s lasers, which we covered several years ago.

31 thoughts on “Legit Hack Creates TEA Laser Power by Mr. Wimshurst

    1. Hmm, I wonder if it could be powered up by an electric eel. That would be a step in right direction toward … mnah, too much voltage would mess up their sensitive ampullae of Lorenzini …

  1. TEA lasers are apparently capable of megawatt-pulses at >1 kHz when the spark gap is replaced with a solid-state switch such as a Thyratron tube. These days maybe even an IGBT stack, although it might become very expensive.

    1. W….T….F….? “solid-state switch such as a Thyratron tube”

      Um, I think you may want to re-read what you just typed…..

      Thyratron tube != Solid state. No way, no how…

      I think you meant Thyratron OR a solid state switch.

  2. So…what would it take to replace the (complex and unusual) Wimshurst machine with (simple-but-dangerous and available) capacitors and coils? More specifically, which caps & coils to make it all go?

      1. My idea:

        A TEA laser can be made cheaply and effectively. And the frequency can be ramped up to 120Hz. A mirror can be positioned that reflects the laser down only one side.

        Now, add a X/Y gantry with mirrors. Could this be made into a laser cutter, cheaply? It’s said the power is in the MW, as a pulse. Is this enough to cut metal?

        1. Megawatt peak powers are high enough to ablate (vaporize) metal. This guy does not get MW peak powers, as his cavity length is too short, his gap spacing is too inconsistent, and the electrical discharge energy is too low to dissociate enough of the nitrogen within the gain volume.
          20Hz is a pretty common rate for a nitrogen laser, and you could do 120Hz, but you would need a multi kilowatt high voltage power supply. So, I guess the short answer is no, you could not build a cheap laser cutter with one of these.

          1. So, how much power is feasible with a setup like this? What is an accurate ERP of this laser? Are there ways to improve on this whilst keeping costs down?

            If we go higher than 15kW DC input, would it be a good way to generate xrays? I can think of many practical applications with a steady xray source, including volumetric 3d scanning (and not this surface stuff).

          2. Average power of 5 milliwatts at 60Hz, peak powers in the 100 to 300 watt range depending on the speed of the discharge (and therefore the pulse width of the laser pulse). This gives a pulse energy of ~80 micro Joules. The wavelength of the X-rays produced depend on the voltage used to create them, so you can generate X-rays at 15kV, but 40 or 50kV would be better. The aluminum rails used for the construction of this laser are not good for producing X-rays. You would need a higher atomic number element like tungsten. You won’t get an X-ray laser though, as the X-rays will just travel outward in all directions.
            I don’t know what ERP stands for in this context.

        2. Nitrogen lasers have been around a long time but have only found use in niche applications. The problem with running at 120Hz is the pulse energy would only be a few micro Joules with this setup, and would really only be good for photo-polymerization or (maybe) pumping a very weak dye laser.
          The biggest problem with nitrogen lasers, and TEA lasers in general, is the non-Gaussian beam profile, which limits the focus-ability of the beam.

  3. Lest you think this is new –

    In the Amateur Scientist column, on page 122 of the June, 1974 issue of Scientific American, there was a design for a tabletop nitrogen laser. It was written by someone named Jim Small, who was a student at MIT at the time. The article was later republished in the Scientific American book Light and Its Uses, and is also on the CD of Amateur Scientist columns, which you can get from The Society for Amateur Scientists.
    http://jossresearch.org/2011/05/16/your-diy-nitrogen-laser-is-not-a-blumlein/

    1. My gods! Poor Hodges! He’s electrocuted, thrown across a room, has his eye burned out by a laser, and suffers illness from breathing mercury fumes, all during his dogsbodying for Ernest Glitch! When he’s permanently blinded in one eye, that’s the last straw, so Ernest FIRES him! Thanks a lot, Ernest! What a bastard!

      And I’m not even halfway through reading it yet! Every new paragraph gives poor Hodges another brush with death!
      Charles Dickens should’ve written about this guy, but nobody would have believed him.

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