Thyratron for CVL

[mixedgas]

Gus, when you come get your thyratron out of my garage, this is the airline I booked your flight on: For all you EEs here, calculate the capacitance, and then the current based on the length of the arc.

http://www.youtube.com/watch?v=Z3q9WdjD5wc

Steve

[GooeyGus]

He could use TSGs and be a lot quieter and happier.

sparks roar and burn up half your excitation.

Steve

TSGs? Tungsten spark gaps? That was purely a guess.

The only thing I'm worried about with a spark gap is getting the second pulse in fast enough to get lasing, before the Br grabs onto the Cu again. I guess it all just depends on how strong of a power supply I use.... Ideally i'd like to run the thing at a few Hz so it doesn't appear to be pulsing; I'm getting too far ahead of myself... I'll get it built first

[mixedgas]

TSG means triggered spark gap...

Oh, and its two gaps.

charge and discharge.

makes life easier.

here is why you want to do it:

http://www.laserfx.com/Backstage.Las...9saturday.html

That was 5 watts outdoors, I'm in the top left picture some place as a outlined figure.


Steve

[QUAZAR]

Is a diffracted beam from the CuBr laser considered "audience safe"?
What are the MPE levels from those beams?

[GooeyGus]

beautiful....

So would I use a triggered spark gap in place of a thyratron or together with one?

I'm new at the mechanics of all this HV stuff, but I know enough to not get myself killed

[mixedgas]

Is a diffracted beam from the CuBr laser considered "audience safe"?
What are the MPE levels from those beams?

Oh, the ground level picture, those were Attenuated, greatly attenuated, compared to the overheads.. LMR lives in Canada, and I can quote him"Where lasers are legal and guns are dangerous", which is was his stock line for us Yankees.

He did NOT normally audience scan with it, and everybody there had signed a waver. Everyone was walking around those beams and not looking into them. we were NOT stupid about it, and only a few people walked into the array, ones with prior experience. We actually were more concerned about a qswitched green pointer that made its debut that evening, the first green pointer I had ever seen. ran with a 50/50 duty cycle and qswitched.

Steve

[lasersbee]

Hey GG...

IIRC... a thyratron is a like an SCR (Silicone Controlled Rectifier) it has an Anode...
Cathode and a Gate.. It is normally not conducting..
Putting a small positive potential (compared to the Cathode) on the Gate will trigger
the SCR to conduct like a Diode.. To stop the conduction (turn it off)... you need to
lower the Anode voltage to almost zero.
The heaviest ones I've seen were used in an Electronic Speed controller for forklifts...
Rated @ 350Amps 600V...

Jerry

[QUAZAR]

Thanks Steve. Judging by the amount of knowledgable people there, I didnt think anyone would walk into those beams if there was any risk. That they were attenuated explains a lot, as i didnt think that it would be safe otherwise.

[Doc]

Gus, when you come get your thyratron out of my garage, this is the airline I booked your flight on: For all you EEs here, calculate the capacitance, and then the current based on the length of the arc.

http://www.youtube.com/watch?v=Z3q9WdjD5wc

Steve

Looking at the paleness of the arc; I'm guessing a couple of nF and low hundreds of milliamperes.

[heroic]

Looking at the paleness of the arc; I'm guessing a couple of nF and low hundreds of milliamperes.

Given that it's several hundred thousand volts based on the length when the chopper parts from the wire (~60 cm), I would suggest that hundreds of milliamps would melt things, so, uh, no. A couple of mA, 4 nF and 300 kV or thereabouts is my calculation. That said, a lot of the arcing will actually be drawn by corona loss at the wingtips of the rotor, since there is cavitation there and thus the pressure is reduced, enhancing corona production.