**1. NAME AND TITLE**

MEDUSA-PIJ: One-Dimensional Laser Fusion Analyzer (Including Neutron Heating Effect)
Collision Probability Method.

**AUXILIARY ROUTINE**

CALCOMP: Plotting package.

**2. CONTRIBUTOR**

Japan Atomic Energy Research Institute, Tokai-mura, Naka-gun, Ibaraki-ken, Japan.

**3. CODING LANGUAGE AND COMPUTER**

Fortran IV; FACOM 230-75.

**4. NATURE OF PROBLEM SOLVED**

MEDUSA-PIJ calculates one-dimensional hydrodynamic and thermodynamic behavior such as the
implosion and burning process of laser-driven plasma.

**5. METHOD OF SOLUTION**

The energy deposition due to the emitted neutrons is calculated by the collision probability method.
The total energy deposition is considered in the energy balance equation of the system at each time
step, and a hydrodynamic equation is solved with Lagrangian coordinates. Neutron spectra escaping
from the fuel sphere are calculated by a neutron slowing-down equation derived under the two-collision
model.

**6. RESTRICTIONS OR LIMITATIONS**

The maximum number of Lagrangian meshes is 150. The maximum number of regions used for
collision probability calculation is 10.

**7. TYPICAL RUNNING TIME**

The running time is about 60 minutes for a case with 30 Lagrangian meshes and 10 regions for
calculating collision probability.

**8. COMPUTER HARDWARE REQUIREMENTS**

The code was designed to operate on the FACOM-230/75 or CDC 6600 computers. **The version
offered by RSIC is operable on the FACOM-230/75.**

188 K words of core storage are required.

**9. COMPUTER SOFTWARE REQUIREMENTS**

A Fortran IV compiler is required.

**10. REFERENCE**

H. Takano and Y. Ishiguro, "MEDUSA-PIJ: A Code for One-Dimensional Laser Fusion Analysis
Taking Account of Neutron Heating Effect," JAERI-M8186 (March 1979).

**11. CONTENTS OF CODE PACKAGE**

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

**12. DATE OF ABSTRACT**

January 1982.

**KEYWORDS:** BREMSSTRAHLUNG; COLLISION PROBABILITY; NEUTRON; ENERGY
DEPOSITION; ONE-DIMENSION; ELECTRON; HYDRODYNAMICS; CTR