CadenceCivet

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A 29 year old civet furry who works on sewage infrastructure (Yes, I’m a wrench-turner) and occasionally dabbles in fictional worldbuilding. Profile pic by Yutmutt on Furaffinity.net


atomicthumbs
@atomicthumbs

the datasheet of this Osram Xeradex excimer lamp says not to touch the lamp while it's in operation, but it's not necessarily because touching the lamp would damage it, or because it gets hot.

the lamp emits 172nm vacuum ultraviolet radiation, shorter-wave and higher-energy than even the UVC emitted by germicidal lamps and EEPROM erasers. it's called "vacuum ultraviolet" because it's absorbed by the oxygen in air, making ozone and excited oxygen. as long as you have ventilation, you can look at a VUV lamp all day with no ill effects. the light emitted in the picture is coming from fluorescence of the lamp envelope, ionization of the air, or both (i'm not sure).

but if there's no air between the lamp and your skin...


vogon
@vogon

saw a mention of a PLC in the lamp datasheet -- which immediately says "this is useful for some industrial purpose" -- and one thing led to another and I found out that 172nm excimer lamps are used, perhaps among other things, for flash-curing the surface of varnishes because their surface absorption causes the nano-scale structure of the varnish surface to wrinkle and craze so the varnish comes out matte, while allowing the bulk of the varnish to cure properly

hell lightbulb


qualia
@qualia
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CadenceCivet
@CadenceCivet

UV lights are fascinating and absolutely terrifying the more you look into them with an industrial use context

Does this mean I’m going to stop being absolutely arrow-in-the-brain and not look at the shiny lights through the grating briefly on a cold night while doing rounds? Hell no


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in reply to @atomicthumbs's post:

i’m so curious as to why this lamp exists and what its use-case is.
Also frankly I want to know what would happen if you were exposed directly to the VUV light, knowing what UV-C does.

172nm ultraviolet light is in the middle of UV-C, but not quite 121nm, which is considered the boundary for ionizing radiation. Still, the way this light interacts with oxygen is much like how ionizing radiation interacts with atoms. When you get radiation sickness, it's because atoms in your body are got ionized and those ions are chemically damaging everything around them. You don't want excited oxygen atoms or ozone in your body.

Getting exposed to this light would be similar enough to getting exposed to x-rays or gamma rays, except this light won't penetrate you the way those shorter wavelengths will.

Which means you would probably need much more exposure than even with lower-energy UV to get substantial damage, since it will likely be stopped still in the dead upper layers of your skin. That is a weird thing with ionising radiation, where between vacuum UV and soft xrays, you get much, much lower penetration depths in matter than on either side.

Oh hey, that's the f̴͕̍o̴͙̕ȑ̴̯b̵̺͐ĩ̷͙d̸͙́ḍ̴́ë̵͈́n̶̝͘ ̵̹́l̶͓͗ǐ̷͍g̸̜͆h̸͜͝t̴̹͊ that the arch-mages use to produce the sand-that-thinks

in reply to @vogon's post:

they're also used for "surface modification" which seems to be a general class of technique for using very exciting seeming things (like cold plasma treatment and VUV irradiation) for very boring things (like make drink label adhere to bottle more)

makes sense, I suspect a large chunk of the reason you'd want to make a varnish matte industrially is to be able to apply another surface treatment to it without it flaking off