Re[2]: Bi207

["Cummings, Frederick" <CUMMINFM@inel.gov>]

     Dale,

     The conversion factors from exposure to absorbed dose or dose
     equivalent are complicated.  In this country, two sets are used in
     dosimetry testing standards for standard x-ray beams (those specified
     by the NIST), one in ANSI N13.11 and one in the DOE Laboratory
     Accreditation Program standard, DOE/EH-0027.  The new conversions in
     the ANSI standard are the ones I recommend for the NIST beams, but you
     did not specify the depth at which you wish to determine 'dose'.  If
     you want a full compilation of conversion constants at several depths
     and arranged for monoenergetic 'beams' as well as standard beams, I
     recommend several of the articles in Radiation Protection Dosimetry by
     Grosswendt (e.g., Vol. 32, #4, pp219 - 231; Vol 35, # 4, pp 221-235
     (angular dependence) and Vol. 40 # 3 pp 169-184 (air kerma to dose
     equivalent)).  These conversions are given for monoenergetic 'beams'
     and for standard x-ray beams (ISO specifications).  For a personal
     reference, Dr. Chris Soares at the NIST is presently embroiled in
     determining and recommending Cxs at various depths.  By the way, the
     specification of x and gamma ray fields is changing in the standards
     arena here.  The new reference quantity for photon beams is now air
     kerma at the NIST.  Someday, I suppose, we will all be walking around
     measuring first collision dose instead of good old familiar
     exposure,...sigh.

     Good Luck

     Rick Cummings
     cumminfm@inel.gov
     (208) 526-2765

     Usual disclaimer - what thoughts that might possibly be reflected in
     the above message are wholly my own and should not be construed to
     have any value other than what the reader can find.


______________________________ Reply Separator _________________________________
Subject: Re: Bi207
Author:  RADSAFE (INELMAIL.RADSAFE) at _EMS
Date:    3/28/95 10:22 AM


Does anyone have a favorite reference for the conversion between
R and Rad/Rem as a function of energy?  Bi207 seems to be another
nuclide for which the RHH dose constants differ from other
references / calculations.  What is the methodology used to determine
the dose constants in the RHH?

Dale E. Boyce
dale@radpro.uchicago.edu