**1. NAME AND TITLE**

CASCADE: Monte Carlo Simulation of the Transport of High Energy Electrons and Photons in Matter.

**2. CONTRIBUTOR**

ERDA Health and Safety Laboratory, New York, New York.

**3. CODING LANGUAGE AND COMPUTER**

FORTRAN IV; CDC 6600.

**4. NATURE OF PROBLEM SOLVED**

The transport of an electron-photon cascade in a homogeneous medium is calculated to compute differential flux densities with separate scoring of positrons and electrons. Allowance is taken for the density on the stopping power and for annihilation in flight. Output also includes energy deposited between consecutive boundaries. The usual low energy cutoffs are 0.1 MeV and 2 MeV for photons and electrons respectively.

**5. METHOD OF SOLUTION**

The Monte Carlo method is used incorporating statistical estimation. Changes in direction are assumed to be caused only by Compton scattering, and only longitudinal development of the showers are treated. Electrons are allowed to undergo bremsstrahlung and collision interactions. Photons undergo pair production, photoelectric absorption, and Compton scattering.

**6. RESTRICTIONS OR LIMITATIONS**

None noted.

**7. TYPICAL RUNNING TIME**

Running time depends strongly on input energy, slab depth, number of energy and spatial groups scored. Approximately 1/3 sec per history for 10 GeV input, 6 energy bins, 25 spatial bins (CDC 6600).

**8. COMPUTER HARDWARE REQUIREMENTS**

The code is operable on the CDC 6600 computer.

**9. COMPUTER SOFTWARE REQUIREMENTS**

A FORTRAN IV compiler is required.

**10. REFERENCE**

Output from Sample Problem.

H. L. Beck, "A Monte Carlo Simulation of the Transport of High Energy Electrons and Photons in Matter," HASL-213 (October 1969).

**11. CONTENTS OF CODE PACKAGE**

Included are the referenced document and one (1.2MB) DOS diskette which contains the source deck and sample problem.

**12. DATE OF ABSTRACT**

June 1972; updated April 1975.

**KEYWORDS:** ELECTRON; GAMMA-RAY; MONTE CARLO; ELECTROMAGNETIC
CASCADE; SLAB; ONE-DIMENSION