[ RadSafe ] Calculate Dose from Flash X-ray?

[Scott Davidson]

> The vendor said the measured dose at 1 meter from a 450 kV, 6000 A X-Ray
> unit with a 25 nanosecond burst is 18 milli-R.  Is there a way to
> calcualte
> the expected beam strength from this unit?  thanks

Group-

There are two curves in NCRP 147 on page 126 that may help approximate
but the kVp in the above question is well above the upper end of the
formula.  The curve fitted as

Air Kerma at 1 m per Unit Workload (mGy mA^-1 min^-1) = 1.222 -
(5.664E-02)*kVp + (1.227E-03)*kVp^2 -(3.136E-06)*kVp^3 looks pretty
straight for most of the line that is fitted and both abscissa and
ordinate are linear plot so that may be a good "approximation" but no
more than that.

Anyone have an equation for this energy?

B. Scott Davidson, CHP, CSP