1. NAME AND TITLE

LRSPC: Range and Stopping Power Calculator

LRSPC is one of a series of space codes developed in the 1960s. Between 19661968, this code package was distributed five times. RSIC retains the series to preserve space technology.

2. CONTRIBUTOR

Lockheed-Georgia Company, Nuclear Analysis Department, Marietta, Georgia.

3. CODING LANGUAGE AND COMPUTER

FORTRAN II and FAP; IBM 7090 and 7094.

4. NATURE OF PROBLEM SOLVED

The LRSPC program is designed to estimate the energy loss, due to ionization and excitation, and the range of charged particles passing through matter. The code treats protons in elements or mixtures composed of elements with atomic numbers ranging from 1 to 100. The results for protons are generally valid from 1 MeV to 100 GeV. The code may be extended to treat other charged particles such as muons, pions, hyperons, deuterons, tritons, and alphas by changing the particle mass, charge, and range at 2 MeV.

5. METHOD OF SOLUTION

Stopping power is calculated from the Bethe-Bloch equation with shell and density corrections included. Range is calculated by integrating the reciprocal of the stopping power from an initial value at 2 MeV. The K-shell correction is taken from Walske's data. The L-shell and higher shell corrections are adjusted to fit low energy measurements for 30 elements. The density correction is calculated by a method similar to that of Sternheimer, differing chiefly in the large number of electron shells considered.

LRSPC computes improved proton range and stopping power data for use in the proton penetration code, CCC-51/LPPC. It is packaged separately and may be requested independently.

6. RESTRICTIONS OR LIMITATIONS

Number of elements in mixture < 10

Atomic number of element < 100

Number of energy points < 500

7. TYPICAL RUNNING TIME

The code runs approximately 16 seconds per element for values at 230 energies. Estimated running time of sample problem: 2 minutes, 20 seconds.

8. COMPUTER HARDWARE REQUIREMENTS

The code is designed for the IBM 7090 and 7094. It requires standard input, output and punch tapes, two working tapes, and an on-line printer for operator instructions.

9. COMPUTER SOFTWARE REQUIREMENTS

The code requires a standard IBM FORTRAN II Monitor or the IBM IBSYS operating system with a FAP assembler and a FORTRAN II compiler.

10. REFERENCE

C. W. Hill, W. B. Ritchie and K. M. Simpson, Jr., "Data Compilation and Evaluation of Space Shielding Problems, Vol. I, Range and Stopping Power Data," ER-7777 (July 1965).

11. CONTENTS OF CODE PACKAGE

The package contains the referenced document and one (1.2MB) DOS diskette on which is writtenin separate filesthe source card decks, data for a sample problem, a BCD data library, and output from the sample problem.

12. DATE OF ABSTRACT

July 1967; updated July 1981, February 1985.