I was reading about gas tubes (Thyratrons, Dekatrons), if I understand it correctly, their maximum frequency is limited by how fast can the gas become plasma and then turn back into gas again to stop conducting current. Particulary this site about dekatrons.

Pure hydrogen seems fastest at 1 MHz, then various helium based penning mixtures at 100 kHz to 20 kHz and slowest is neon at 4 kHz. Is there some list on the internet that shows the maximum frequency/deionization times for gases and gas mixtures? If not, can you tell me, is there way to calculate it?

Does pressure of the of gas affect maximum ionization/deionization speed? Does thermal conductivity of material that surrounds the gas have impact on the maximum frequency?

Another thing I would like to know is, I reed about Carbon Nanotube thermoacoustic speaker made by some two people from university. I read their article and it said Carbon Nanotubes can play music by thermoacoustic effect but water or other materials can't because carbon nanotubes can be heated and cooled more than 20000 times a second thus being able to create frequencies up to the upper limit of audible spectrum for humans but other materials cant do that fast enough so they cant cover full audible spectrum.

The ionization and deionization is heating and cooling of gas, it goes from gas to plasma, and back to gas (right?). Is the ionization and deionization maximum frequency like in gas tube device same thing/synonym as maximum frequency the gas can expand and shrink by heating and cooling like the thermoacoustic effect?

  • $\begingroup$ Can you please cite your source for thyratron speeds? It sounds a little bit slow from memory. $\endgroup$ Nov 18, 2016 at 2:01
  • $\begingroup$ WetSavannaAnimal aka Rod Vance I only reed about the speeds in the internet site about dekatrons,I am pretty sure I reed some declasified paper about crossatrons made US Navy,I think there were similiar speeds mentioned.Anyway,I would love to hear from you the speeds that you remember,I could be compeltly wrong,it might be faster as you say. $\endgroup$ Nov 18, 2016 at 2:12
  • $\begingroup$ Have you looked up recombination and/or the Saha equation? Also, you should separate your carbon nanotube question from the first part to avoid having the question closed by the moderators (it's important to keep the question focused to increase the probability that it will be answered). $\endgroup$ Nov 18, 2016 at 13:37


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