[Mike Garrard]

Mike Garrard  asked the Naked Scientists:
   
FAO Dave Ansell:
 
As you called it dangerous, I thought I'd investigate
 
I am in the process of hooking up a demo engine controller for a different project, so I will shortly have a controlled spark generator, currently feeding sparkplugs.  However, when I look at your video here:
http://www.thenakedscientists.com/HTML/content/kitchenscience/garage-science/exp/tea-laser-how-lasers-work/
it looks to me as if your secondary gap is also occasionally breaking down and emitting.  On the mp3 you say that the LASER in the gap emits UV and this excites light.  How can you tell the difference between this and gap breakdown exciting molecules and thus also emitting light?  There is a delay between the click of the discharge and the flash of the light: is this the indication of lasing or just a digital artifact?
 

Mike Garrard

What do you think?

[daveshorts]

Yes it certainly wasn't working well, some of the shots seemed to produce a bright spot rather than a line which you would expect from a spark or a diffuse source. The stimulated emmission means that light that passes along the chamber is amplified so forming a spot.

 I had great difficulties getting it to even work this well, I think because I couldn't get the shape of the plates right.