Instantaneous Unit Conversion between CGS and SI units

AI Thread Summary
The discussion revolves around the conversion of the CGS unit "erg/(sec rad cm)" to SI units for power, specifically watts. Participants clarify that this unit may represent intensity rather than power, suggesting it should be expressed in steradians instead of radians. The original poster confirms the context involves synchrotron radiation from a particle beam, linking it to the relativistic Larmor formula. They eventually found a different equation in SI units that provided reasonable results, highlighting confusion due to inconsistent unit usage in reference materials. The conversation emphasizes the importance of understanding unit contexts in physics.
KJ4EPE
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In doing some research, I cam across an equation for instantaneous radiated power, with the CGS units "erg/(sec rad cm)", rad being radians (not rad the unit for radiation exposure). Try as I might, I'm not able to come up with a way to convert it to the SI units for watts. Does anyone know where I might find the information about this?
 
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Hi KJ4EPE! :smile:

Are you sure this is power? erg/(sec rad cm) looks more like some form of intensity …

there's a useful table of intensities and radiances at http://en.wikipedia.org/wiki/Intensity_(physics)"

but I can't see anything there equivalent to erg/(sec rad cm) :confused:

(and I'd expect steradian instead of radian … erg/(sec rad cm) looks to me cylindrical rather than spherical … is this for a "cylindrical" transmitter?)
 
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Actually it is! It's for determining the power of synchrotron radiation emitted from a particle beam, essentially the relativistic form of the Larmor formula. But anyway, someone at work was able to point me in the direction of a different equation in SI units, and the results seem to be reasonable. I was confused cause one of the books I was using this morning used the same equation for both SI and CGS units, and I had a hard time figuring out what to use.
 

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