P-Factors

[David Allyson <D.Allyson@surrc.gla.ac.uk>]

Dear RADSAFE Members

I would be most grateful for a source of information about P-factors and
their use - particulary with surface contamination monitors, in converting
from instrument response (cps) to a surface activity (Bq/cm2).  Is the term
itself (P-factor) widely acknowledged?  P-factors can have values from 2
(for gamma's), to 4 or higher (for alpha's and soft beta's).

Surface activity Bq/cm2 =

[Instrument response (cps)/Instrument response factor (cps/ surface
emission rate)] * P

surface emission rate = particles /s/cm2 into 2 pi (from a certified standard)

Is there a listing somewhere where I can find the most suitable P-factor
for a given substrate?

Many thanks

Dr David Allyson
Decommissioning Health Physics
Scottish Universities Research & Reactor Centre
East Kilbride
Glasgow
Scotland

D.Allyson@surrc.gla.ac.uk

 

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