- #1
artis
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- 976
I just realized I'm having a problem in understanding this.
So let's take an example the CMB is around 160 Ghz and the blackbody temperature within this frequency range is 2.7K which is rather cold as it is close to absolute zero.
Then let's take another example, Iter plasma will achieve about 150 000 000 degrees Celsius. One of the heating mechanisms will be RF heating.
I read that there are Gyrotrons already made for Iter that work at 170Ghz.
Here is what I don't understand, a black body radiating at 170Ghz is close to absolute zero temperature wise, yet pumping 170Ghz radiowaves into a plasma can push its temperature to millions of degrees Celsius?
Clearly the black body radiation frequency of a 150 million celsius object isn't 170Ghz but way way higher.
Ps. I guess there is also a simpler example , a LED, where the actual temperature of the LED die is lower than that of the emitted EM radiation.
So let's take an example the CMB is around 160 Ghz and the blackbody temperature within this frequency range is 2.7K which is rather cold as it is close to absolute zero.
Then let's take another example, Iter plasma will achieve about 150 000 000 degrees Celsius. One of the heating mechanisms will be RF heating.
I read that there are Gyrotrons already made for Iter that work at 170Ghz.
Here is what I don't understand, a black body radiating at 170Ghz is close to absolute zero temperature wise, yet pumping 170Ghz radiowaves into a plasma can push its temperature to millions of degrees Celsius?
Clearly the black body radiation frequency of a 150 million celsius object isn't 170Ghz but way way higher.
Ps. I guess there is also a simpler example , a LED, where the actual temperature of the LED die is lower than that of the emitted EM radiation.
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