What is Intensity of Ray? Where to Get Info?

[ATPenergy]

What is this equation I_$$\gamma$$=($$\Gamma$$N)/D²

It is about Intensity of ray.
But I can't find any information about it.
What is it? And where can I get the information?

 

[tiny-tim]

Hi ATPenergy!

What is this equation I_$$\gamma$$=($$\Gamma$$N)/D²

It is about Intensity of ray.
But I can't find any information about it.
What is it? And where can I get the information?

I'm not sure, but it looks a bit like irradiance = radiant flux (or radiant power) per area …

see http://en.wikipedia.org/wiki/Radiant_flux"

what book did you get it from?

 

[Rajini]

Hi,
i think it is the relation between natural line width, mean life time and Planck's constant!
the correct relation which i know (FWHM)*meanlifetime=hbar.