Instantaneous Unit Conversion between CGS and SI units

KJ4EPE

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?

tiny-tim

Hi KJ4EPE!

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)

(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?)

KJ4EPE

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.