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By Jon Singer on April 28, 2011
TJIIRRS: Number 21
A Look At Some Room-Pressure (TEA) Nitrogen Laser Designs
(04 April, 2011, ff)
!! WARNING !!
These lasers use high voltages, and capacitors that can store lethal amounts of energy. They put out invisible ultraviolet light that can damage your eyes and skin. It is important to take adequate safety precautions and use appropriate safety equipment with any laser; but it is crucially important with lasers that involve high voltages and/or produce invisible beams!
If you use an open spark gap, you need to be aware that it will destroy your hearing unless you use adequate ear protection. I strongly suggest a pair of earmuffs of the type used by people at rifle and pistol ranges, and it is a good idea to use earplugs in addition to the muffs. If you aren’t using adequate hearing protection, an open spark gap will also give you a nasty headache if you run it for a while.
The nitrogen laser was discovered in 1963. Originally, this laser was operated at moderate pressure, roughly a dozen to a few dozen Torr of nitrogen. Although it fairly quickly became clear that the addition of helium did not interfere, and
By Jon Singer on April 7, 2011
TJIIRRS: Number 2 of an Ongoing Series
In Pursuit of Yohen Tenmoku
Late April, 2005
When you decide to replicate an ancient glaze, there are usually a few paths you can take. If there’s an analysis, for example, you can try making a glaze with that composition and working from there. If there are modern glazes with similar appearance, you can start with one or more of those and tweak.
In the case of Yohen Tenmoku, unfortunately, we don’t quite have either of those options. The ancient glazes are among the rarest of Song pieces; there is an iridescent oilspot bowl (just one) in the Miho Museum, and three bowls in other museums, all of which resemble each other in terms of glaze and effect but are not standard oilspot. (We’ll deal with the Miho Museum’s bowl later: I haven’t even started on that one yet.) There are no shards of either type that I’m aware of, and so there are no analyses. Nobody knows exactly where or when these bowls were made, though I think they are very clearly Jian ware. All of these are designated National Treasures and Important Cultural Objects, if my information is » Read the rest
Joss Research Institute Web Report #16B: Continuing Look into Hollow-Cathode Helium-Metal Laser Designs for the DIYer, part 1
By Jon Singer on April 6, 2011
TJIIRRS Number 16B:
Further Examination of Possible Hollow-Cathode
Laser Designs for the Do-It-Yourselfer
Part 1: Quadrupoles
(01 January, 2011, ff)
Note: A dipole has 2 parts, and it has opposite charges or poles across from each other:
A quadrupole has 4 parts, and it has like charges (or poles) across from each other:
+ - - +
This page describes the process of constructing and debugging several hollow-cathode lasers that are operated as quadrupoles. The first is made of copper tubing, and uses sputtered copper vapor in a helium buffer, probably with a small amount of argon added to it to enhance the sputtering. The second is built of stainless-steel tubing; it will use a mixture of helium and iodine or helium and argon as its active medium, and will not require sputtered metal. If I get really ambitious there may be a third and fourth, formalized versions of the first two, possibly with different insulators.
My effort is to make these lasers relatively easy to construct and operate, and to avoid parts that are expensive, difficult to obtain, or require much machining.
Side note: it became clear to me, in the course of working with