**1. NAME AND TITLE**

PIPE: Numerical Gamma-Ray Transport Code System for Plane/Spherical Geometry.

PIPE is based on CCC-66/BIGGI-3P,4T. BIGGI can be used for calculations referring to
albedo or pair production effect. For all other types of problems, PIPE is recommended.

**2. CONTRIBUTOR**

EURATOM, Ispra (Varese), Italy, through the OECD NEA Data Bank, Gif-sur-Yvette,
France.

**3. CODING LANGUAGE AND COMPUTER**

FORTRAN IV; IBM 360/370.

**4. NATURE OF PROBLEM SOLVED**

PIPE solves the time-independent gamma-ray transport equation, with Compton scattering only,
for slab or spherical multilayer geometry. Photoelectric and pair-production processes are treated
as absorptions. Bremsstrahlung, fluorescence, and Rayleigh scattering are ignored.

**5. METHOD OF SOLUTION**

The basis of the solution is the couple of integral equations described by Weinberg and Wigner
as "the third form of the Boltzmann equation." The energy dependence is treated within a group
scheme, the angular dependence by fixing angular mesh points (which can be chosen rather
arbitrarily). The spatial treatment takes into account the exponential attenuation directly, an
exponential transformation can be applied, and these two features allow large spatial integration
steps, up to two or three (m.f.g.) in thick layers.

**6. RESTRICTIONS OR LIMITATIONS**

PIPE allows a maximum of 34 elements in the cross section library, 20 materials, 20 layers, 12
source energies, 11 angular, 50 spatial, 60 energy mesh points, and 6 arbitrary response functions
which can be applied to the spectra or to the angular fluxes.

**7. TYPICAL RUNNING TIME**

PIPE problems run in 1 to 3 minutes on an IBM 360/65 computer. The packaged sample
problems ran in approximately 1 1/2 minutes on an IBM 360/91 computer.

**8. COMPUTER HARDWARE REQUIREMENTS**

PIPE is operable in the IBM 360/370 computers.

**9. COMPUTER SOFTWARE REQUIREMENTS**

A FORTRAN IV compiler is required.

**10. REFERENCES**

a. Included in the documentation:

H. Penkuhn, "How to Use the Gamma Transport Code PIPE," EURATOM Report ISPRA-1437; EUR 4624 (April 1970).

H. Penkuhn, "PIPE: A Programme Integrating the Photon Equation Designed for Gamma
Shielding Calculations," paper presented to the NEA Computer Programme Library's Seminar on
Shielding Programmes (October 1972).

b. Background information:

H. Penkuhn, "User's Manual for the Gamma Transport Codes BYGGI 3P and BIGGI 4T," EUR 3555e (1967).

A. M. Weinberg and E. P. Wigner, "The Physical Theory of Neutron Chain Reactors,"
Chicago: The University of Chicago Press, 1958, p. 228.

**11. CONTENTS OF CODE PACKAGE**

Included are the referenced documents and one (1.2MB) DOS diskette which contains the
source code and sample problem input.

**12. DATE OF ABSTRACT**

July 1975.

**KEYWORDS: ** DISCRETE ORDINATES; NUMERICAL INTEGRATION; GAMMA-RAY;
ONE-DIMENSION; SLAB; SPHERICAL GEOMETRY