[ RadSafe ] Buildup factor for compounds

[Harold Careway]

Or see Oak Ridge data library collection DLC-129, Daniel.  You really don't
need the program as an excel workbook with the data library can be built to
do the job.  Generally it can get you pretty close to where you want to go.

 

Hal Careway

 

The ANS-6.4.3 1988 buildup factor database is being made available by
placing a file of Geometric Progression (GP) coefficients and a sample
"retrieval" program, Daniel, in the Radiation Shielding Information Center
Data Library Collection. The coefficients were determined in Japan from the
1988 compilation of ANS-6.4.3. The work by the group continues, and it is
expected that additional revisions will be made.

 

The present database is an update of the 1985 database. Many revisions have
been made, the most significant is the complete replacement of the tables
from molybdenum to uranium. The data for those elements are from PALLAS
results and include the effect of bremsstrahlung due to high-energy
electrons from photon interactions. The beryllium data have been
significantly revised, and the following elements have been added: tin,
lanthanum, gadolinium, and tungsten. The GP coefficients have been revised
throughout the database, mainly to improve interpolation in thecoefficients.
The ANS-6.4.3 compilation is described in Ref. 1.

 

The present file has data for Be, B, C, N, O, Na, Mg, Al, Si, P, S, Ar, K,
Ca, Fe, Cu, Mo, Sn, La, Gd, W, Pb, U, water, concrete, and air. Two buildup
factors are available: exposure (air response) and energy absorption. Most
of the buildup factor data for the elements up to copper is based on moments
method results from the U.S. National Bureau of Standards; the remainder is
from PALLAS results. Results from ASFIT have been used in the validation
process.

 

The Daniel program consists of a main routine to print tables of buildup
factors. It will print any number of tables covering the energy range of
0.02 to 15 MeV for thicknesses up to 60 mean free paths for each material
specified in the input. The GP coefficients are read from a data file. The
input consists of lines specifying the material and response in a 2A4
format. The sample problem input is:

*        CARB EXP

*        CARB ABS

*        AIR ABS.

*        AIR EXP

*        CONC EXP

The possible input to specify materials are: BERY, BORO, CARB, NITR, OXYG,
SODI, MAGN, ALUM, SILI, PHOS, SULP, ARGO, POTA, CALC, IRON, COPP, MOLY, TIN,
LANT, GADO, TUNG, LEAD, URAN, WATE, CONC, AIR. The program has been revised
to accommodate these 26 materials.

 

Interpolation in energy allows any energy mesh but can only be changed by
revising the main routine. Extrapolation beyond the input buildup data (40
mfp) is allowed up to 60 mfp in the subroutine LITEBF.

 

 

 

Hello Radsafers:

> 

>        Is there an established or preferred method for estimation the

>        dose buildup factor for compounds or mixtures of shielding

>        materials?  I am trying to come up with reasonable values for

>        things such as barite loaded concrete or iron loaded concrete.

> 

>        Thanks in advance

> 

>        Kai Kaletsch

>        Environmental Instruments Canada Inc.

>        http://www.eic.nu/