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Re: Nitrogen laser power level and gas mixture


    Air would work, and what you would need is two surface mirrored mirrors
with protective coatings.  One has to be a beam splitting mirror, because
the light that would be between them has to escape.  I don't know if the
light will be in the visible spectrum or not, but almost any gas can be
excited state and lase.  Atoms are the most important component because they
absorb the light as a change in the orbital electron's energy level, and
when an electron changes energy levels it emits a photon, and that's why the
spark is luminescent on low current coils.  In other words it has to do with
temperature, and everything to with high energy level changes in the air
around it.  So, yes it will work.

   Second, you will need lenses, because lasers that run at a higher
temperature tend to melt, or deform mirrors and lenses with heat.  So,
focusing the light from the output would help save the mirrors but not the
last lens.  One would need to be convex, the other concave if you are going
to focus a tight beam.  The last lens has to be the concave lens and should
be made of a high temperature glass.

    Third you will need xenon flash bulbs to drive it, and a power supply to
supply the current at 200, to 300 volts DC, for the flash brightness.  This
is usually about .1 uF, and can be as high as 1uF.  You will need a trigger
circuit that can provide the bulbs with 2 Kv, to 4 Kv at a relativly low
current, it will only be felt through the glass to initialize an arc through
the bulb.  These should run paralled to eachother on either side of the
mirrors if they were placed in a box.  If the mirrors measure 3 inches in
diameter, and the box were a foot long, the flash bulbs would be parallel to
the foot long section, but not between the mirrors, which should be facing
eachother.   It is usually better to control the frequency of the trigger
voltage, and be sure that the DC does not exceed 300 volts, but if the bulbs
you buy are rated differently, then follow the specs, and give yourself a
margin.  If the specs say between 200 v, and 400 v, don't exeed 350 v.  The
trigger can be higher because the current demand is low, and almost nill,
and only meant to be felt.

    The spark gap is needs to be about a milimeter away from the beam, the
dielectric constant of air is 20 volts to the milimeter.  So, from there you
will still have to adjust the distance between the gap's electrodes, even
though the spark length will be increased by the beam.




>Original Poster: "Doug Brunner" <dabrunner-at-earthlink-dot-net>
>
>
>Three questions about nitrogen lasers:
>
>What kind of power is needed to fire a TC gap?
>Does the laser have to shine on one of the gap's electrodes, or can it just
>go through the actual gap?
>Can a N2 laser work with air, or does it need pure nitrogen? If so, how can
>I produce it cheaply?
>
>           --Mr. Postman (Doug Brunner)
>                <<mailto:dabrunner-at-earthlink-dot-net>dabrunner-at-earthlink-dot-net>
>