RSICC CODE PACKAGE CCC-430
1. NAME AND TITLE
EDMULT 6.4: Evaluates Electron Depth-Dose Distributions in Multilayer Slab Absorbers.
Institute for Data Evaluation and Analysis, Sakai, Osaka, Japan; Research Institute for Advanced Science and Technology, Osaka Prefecture University, Sakai, Osaka Japan; Shanghai Applied Radiation Institute, Shanghai University, Jia Ding, Shanghai, China; and Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana.
3. CODING LANGUAGE AND COMPUTER
Fortran 77; Intel PC, MacIntosh, Workstations (C00430MNYCP02).
4. NATURE OF PROBLEM SOLVED
EDMULT evaluates depth‑dose distributions produced by plane‑parallel electron beams normally incident on one‑ to six‑layer slab absorbers. Special features of the present version compared with previous ones are as follows:
(1) Higher accuracy (root‑mean‑square deviations from accurate Monte Carlo results are 1‑2% for effectively semi‑infinite absorbers and 5‑7% for absorbers consisting of more than two layers).
(2) Applicability to the absorbers consisting of a larger number of layers of different materials (up to six layers).
(3) Use of the mean atomic number given in ICRU Report 35 (page 37) for material mixtures and compounds instead of the effective atomic number used in earlier versions.
5. METHOD OF SOLUTION
EDMULT is based on an analytic expression of the depth‑dose curve in semi‑infinite medium and a simple model of electron penetration through a multilayer absorber. The effect of the different medium beyond an interface is accounted for by the difference of backscattering, which is evaluated by considering the branching of electron beam into transmitted and backscattered components.
There are no major changes in September 2004 release of EDMULT. Subroutine EDBREM was modified to remove a line that caused a warning-level error when compiling.
6. RESTRICTIONS OR LIMITATIONS
EDMULT is valid for incident‑electron energies from 0.1 to 20 MeV and for absorbers consisting of slabs of atomic numbers from about 4.75 (polyethylene) to 92. When the absorber consists of six layers, the last layer should be thick enough to stop essentially all the electrons incident on it. Treatment of the bremsstrahlung component of energy deposition in multilayer absorbers is yet incomplete.
7. TYPICAL RUNNING TIME
The computation time required to evaluate a depth‑dose profile consisting of 50 points for a six‑layer absorber is less than a second on most desk‑top computers.
8. COMPUTER HARDWARE REQUIREMENTS
EDMULT is operable on any desktop or laptop computers as well as on mainframe computers. The compiled program requires less than 300 K bites of RAM.
9. COMPUTER SOFTWARE REQUIREMENTS
The code should be operable on any operating system with a FORTRAN compiler. The developer ran it on several computers including Macintosh with the Absoft compiler. An executable created with the Lahey 95 V5.60 compiler is included in the package for PC Windows users. EDMULT was tested at RSICC on:
IBM RS/6000 Model 270 running AIX 4.3.3 with XL Fortran Version 7.1
Intel‑Linux 7 with f77 Version 2.96 under RedHat Linux 7
WindowsXP on Pentium IV with Compaq Visual Fortran 6.6b
WindowsXP on Pentium IV with Lahey 95 5.60
a. Included in documentation:
T. Tabata, Readme.txt (June 2002, revised September 2004).
R. Ito and T. Tabata, “Semiempirical Code EDMULT for Depth-Dose Distributions of Electrons in Multilayer Slab Absorbers: Revisions and Applications,” Radiation Center of Osaka Prefecture Technical Report No. 8, RCOP TR-8 (November 1987). (This document refers to an old version, but the method of solution described is the same as the present version. A revised version in the form of a PDF file is under preparation.)
b. Background information:
T. Tabata, P. Andreo and K. Shinoda, “An algorithm for depth‑dose curves of electrons fitted to Monte Carlo data,” Radiat. Phys. Chem. Vol. 53, pp. 205‑215 (1998) (This reference describes the new algorithm of one of the most important subprograms, EDEPOS, used in EDMULT.)
11. CONTENTS OF CODE PACKAGE
The package is transmitted on a CD that includes the referenced document in 10.a and the source, sample problem input and output, and PC executable in a WinZIP file.
12. DATE OF ABSTRACT
May 1992, revised November 2002, September 2004.
KEYWORDS: SLAB; ELECTRON; ONE-DIMENSION; ENERGY DEPOSITION; NUMERICAL INTEGRATION