Someone on another forum shared with me that a 6L6 vacuum tube exhibits a blue dot when in operation that is supposed to be Cherenkov radiation. I say nay, as I have worked out the relativistic velocity using $$KE={ m }_{ 0 }{ c }^{ 2 }\left[ \frac { 1 }{ \sqrt { 1-\frac { { v }^{ 2 } }{ { c }^{ 2 } } } } -1 \right] $$. The plate voltage is 500V max, so I used 500eV for the KE. This works out to $$8x10^{-17}$$Joules. Solving for v, I get v=$$1.3x10^{7}m/s$$. If the speed of light in glass is $$\frac{c}{n}$$, where n=The index of refraction of glass (I will assume 1.5). Then these electrons are not fast enough for Cherenkov radiation. Am I on target here?(adsbygoogle = window.adsbygoogle || []).push({});

Thanks,

Chris Maness

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# Cherenkov Radiation in a Vacuum Tube

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