Re: your mail

[Bernard L Cohen <blc+@pitt.edu>]

On Thu, 28 Jan 1999, Mike Dupray wrote:

> Does anybody know what a 4pi steridian cross section looks like?

	--4 pi steradian is a solid angle of acceptance, not a cross
section. Cross section has units of square centimeters, while steradian is
dimensionless. If a detector of radiation from a source has an acceptance
solid angle of 4 pi steradians, that means that all radiation from the
source reaches the detector, regardless of the angle at which it was
emitted from the source. 


> 
Bernard L. Cohen
Physics Dept.
University of Pittsburgh
Pittsburgh, PA 15260
Tel: (412)624-9245
Fax: (412)624-9163
e-mail: blc+@pitt.edu


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