Switches Used for the Z-Machine

[Henning]

Just a quick writeup of switches used at Sandia Labs for the Z-Machine. I’ve put it in the LPPX section as it could be useful for the experiment. Most likely Eric et al. know about it, just financial constrains got them settled to their current design.

For the Z-Machine they are using LTD switches (Linear Transformer Driver):
http://www.sandia.gov/news/publications/technology/2007/102807/fusion.html#top
https://share.sandia.gov/news/resources/releases/2007/rapid-fire-pulse.html

Article on the motion control of lasers with timing chart and cut-through:
http://www.optoiq.com/index/photonics-technologies-applications/lfw-display/lfw-article-display/articles/optoiq2/photonics-technologies/technology-products/positioning-__support/mounting-and_positioning0/2010/motion-control__automated.html

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In a forum I read something like the folowing…

Done by “Institute of High Current Electronics” in Tomsk (do that now in kyrillic):
http://www.hcei.tsc.ru/en/cat/technologies/tech15.html

The theory behind pseudospark switches:
http://members.tm.net/lapointe/Pseudospark_Switch.html

Maybe that guy can help out with switches (maybe worth contacting by LPP):
http://members.tm.net/lapointe/Main.html

[Aeronaut]

Outstanding links, Henning. I learned a lot from Sandia’s copy writing strategy, too- hadn’t realized how similar their electrical requirements are to ours. Any idea who makes those thermos bottle sized capacitors?

[Henning]

Seems as the producer of the switches is Pulsed Technologies LTD in Russia.

Here are the pulsed drivers: http://www.pulsetech.ru/pulsedrivers.htm

They also produce triggered spark gaps: http://www.pulsetech.ru/3el.htm

[achataignier]

Strange that the producer you mention also produces thyratrons… I think from the beginning that using them might be a very good option for Focus fusion. They are reliable and have been used by the industry for many years now.

By digging in Google, I also found an old (and now in free domain) patent to enhance thyratron technology, for using it in Focus Fusion devices:

http://www.patentgenius.com/patent/4446096.html

[ronh1066]

These sites claim that these switches can fire every 10 sec. Do we need to find a different version, can they actually fire much mor often, do we need to look for a different technology or what?

[mchargue]

ronh1066 wrote: These sites claim that these switches can fire every 10 sec. Do we need to find a different version, can they actually fire much mor often, do we need to look for a different technology or what?

That’s likely due to power-dissipation (heat-dissipation) limitations. Run it too fast, and you get a liquid-switch.

Better thermal characteristics is the fix for that. Bigger, more thermally conductive, electrodes seated in a material that can draw the heat away. Or more switches, or banks of switches operating in sequence.

There are likely few off-the-shelf solutions for high-rate, high-current, high-voltage switches. What seems to be available is you get a trade off between the the first two parameters.

Pat

[Breakable]

Nice thing about vacuum tubes is that they are kind of DIY, unlike transistors.

[Aeronaut]

Breakable wrote: Nice thing about vacuum tubes is that they are kind of DIY, unlike transistors.
http://www.youtube.com/watch?v=gl-QMuUQhVM

Some problems with tubes are that they’re huge and sensitive to mechanical shock.

[Breakable]

Some problems with tubes are that they’re huge and sensitive to mechanical shock.

Those issues can be addressed, and probably the bigger you make them the better they should resist shock. Also I would wonder how scaling of size vs power could work. Imagine a tube made out of champagne bottle.

[Author]

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