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About thyratrons
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PartialDischarge:
I'm considering buying and putting to work a thyratron, probably hydrogen, with the purpose on creating short steep current pulses. For something like 100s of amperes and 50-100us in duration I understand nothing beats the turn on speed of a thyratron.

Well, I stumbled upon one model that is described as both a "mercury vapor rectifying tube" and as a "HV mercury vapor thyratron". So my question is are this the same? I'm missing for example the maximum dI/dt that the tube allows, typical in thyratron datasheets.


Here are the datasheets:

https://frank.pocnet.net/sheets/030/d/DCG7-100.pdf
https://www.relltubes.com/filebase/en/src/Datasheets/DCG7_100%20and%20DCG7_100B.pdf

ArthurDent:
Many years ago I worked at a company where they did testing to see how watthour meters (like you see on the electrical service for houses) stood up to induced high current pulses similar to lightning strikes on power lines. The equipment used a large thyratron to dump a bank of capacitors charged up to 20,000 VDC through a very large conductor running through the meter socket. The resulting pulse was 20 microseconds long and a peak current of 20,000 amps. The pooled mercury in the bottom of the tube was vaporized when the tube was triggered and then the tube would conduct basically becoming a direct short. 
 
If you visualize thyratrons as the tube version of an SCR it may make more sense. They are not linear but triggered diodes or switches.

PartialDischarge:

--- Quote from: ArthurDent on November 08, 2018, 04:27:50 pm --- The equipment used a large thyratron to dump a bank of capacitors charged up to 20,000 VDC through a very large conductor running through the meter socket. The resulting pulse was 20 microseconds long and a peak current of 20,000 amps.

--- End quote ---

Those figures are amazing, a hockey puck thyristor can match that amount of current and of voltage if put in series, but they are much slower in current rise time, and will break if the dI/dt exceeds for example 500A/us, where a thyratron can handle thousands of A/us.
drussell:

--- Quote from: MasterTech on November 08, 2018, 09:31:03 am ---Well, I stumbled upon one model that is described as both a "mercury vapor rectifying tube" and as a "HV mercury vapor thyratron". So my question is are this the same? I'm missing for example the maximum dI/dt that the tube allows, typical in thyratron datasheets.
--- End quote ---

Well, a thyratron is a rectifier, but a "controlled" one, just like an SCR is a controlled version of a silicon rectifier.
N2IXK:
Hydrogen (or deuterium) thyratrons have much faster de-ionization times than mercury vapor or other gas types. They were pretty much the standard for high repetition rate pulsers in radar applications.
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