[HN Gopher] DIY Nitrogen TEA Laser
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       DIY Nitrogen TEA Laser
        
       Author : RicoElectrico
       Score  : 64 points
       Date   : 2023-03-17 17:57 UTC (5 hours ago)
        
 (HTM) web link (physicsopenlab.org)
 (TXT) w3m dump (physicsopenlab.org)
        
       | ChrisMarshallNY wrote:
       | These are such a fun way to go blind!
       | 
       | I remember messing around with a UV laser (pretty sure it was
       | nitrogen, but it needed a pump and all), when I was a young'un.
       | 
       | Never did get it working properly, which is probably good, as I
       | likely would have blinded myself.
       | 
       | I made _lots_ of trouble, when I was a kid. It 's a miracle that
       | I'm still alive.
       | 
       | UV lasers are dangerous. Invisible beams, and all.
        
         | tiedieconderoga wrote:
         | IR lasers, too. Your pupils won't contract because they don't
         | see the light, and a lot of damage can be done very quickly.
         | You might not notice it immediately either, because your brain
         | can paper over small bits of retinal damage to maintain a
         | complete image, like it does with your ocular nerve blind
         | spots.
         | 
         | Lasers are super cool, but I wouldn't DIY one unless I could
         | keep it in a goggles-only room with interlocks on the door to
         | cut power.
        
       | tiedieconderoga wrote:
       | Spark gaps are an interesting way to switch when you get to a
       | high enough voltage. Marx generators use a similar principle,
       | using the spark to place parallel capacitors in series with one
       | another.
       | 
       | https://en.wikipedia.org/wiki/Marx_generator
       | 
       | I've often wondered if gas discharge tubes could serve a similar
       | function at lower voltages, but I haven't gotten around to trying
       | it out.
        
         | ilyt wrote:
         | The whole point of using them is that they work at very high
         | voltages and are very, very cheap. For low voltages there are
         | just many more controllable and consistent ways of switch.
         | 
         | Simple thyristor and cap bank for example. Or just transistor
         | and controller.
        
         | azalemeth wrote:
         | Indeed -- or the highly related Cockroff Walton generator:
         | https://en.wikipedia.org/wiki/Cockcroft%E2%80%93Walton_gener...
        
       | neilv wrote:
       | This page buries and understates vision-related laser safety:
       | 
       | > _It is also recommended not to look directly at the laser beam,
       | to protect the eyes from the UV radiation produced by the
       | discharges, to use hearing protection and to pay attention to the
       | handling of the permanent magnets._
       | 
       | Especially for a page targeted broadly at "science enthusiasts"
       | (in the site's tagline), I'd expect instead to see a glaring red
       | warning at the top, along with _effective_ links to getting this
       | safety.
        
       | [deleted]
        
       | showerst wrote:
       | There's a couple of good videos on these (and other home laser
       | fun) on the youtube channel Les' Lab.
       | https://www.youtube.com/channel/UC0ptp5KuvAJmp8kRV8dqZDA
        
       | kabdib wrote:
       | This reminds me of a similar laser detailed in one of Scientific
       | American's _The Amateur Scientist_ articles from the 1970s.
       | 
       | I grew up reading those articles, they used to be great. You just
       | knew a project was going to be fun when it included a "Model T
       | spark coil" :-)
        
       | aj7 wrote:
       | Loved your use of the magnets! I thought I knew everything about
       | the design and construction of nitrogen lasers but this is a very
       | good idea.
       | 
       | That said, for the non-experts out there, TEA N2 lasers are not
       | very useful because of their low energy outputs and very short
       | (but not ultrashort) pulsewidths. But this is a great example of
       | a laser that could have been built by Volta himself around the
       | time of George Washington.
        
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       (page generated 2023-03-17 23:00 UTC)