Re: Exposure Rate Formula for X-ray Machine

[Sarah_Hayes@student.uml.edu (Sarah Hayes)]

Carl_Tarantino@vapower.com wrote:

> The basic equation for calculating the maximum exposure rate at any occupied
> point at a distance d meters from the target in the x-ray tube is:
>
> Xm = P/T R/week,
> where P = maximum permissible weekly exposure, i.e. 0.1R/week for controlled
> areas and 0.01R/week for uncontrolled areas
>              T = occupancy factor
> Applying the inverse square law, the exposure rate at 1 meter from the target
> may be derived accordingly:
>
> X1 = d2 * Xm = d2*P/T R/week at 1 meter
>
> NCRP Report #49, Structural Shielding Design for Medical Use of X-rays and Gamma
> Rays of Energies Up to 10 MeV, should be consulted as a reference.

*******

Consult NCRP 51 as well.  Are you using the machine for diagnostic or therapeutic
purposes?  The calculations are a little bit different for each.


Sarah Hayes

************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html