**1. NAME AND TITLE**

BALTORO: Code for Coupling of Monte Carlo and Discrete Ordinates Radiation Transport
Calculations.

**2. CONTRIBUTOR**

Institute of Nuclear Physics, Krakow, Poland.

**3. CODING LANGUAGE AND COMPUTER**

Fortran IV; CDC 6600.

**4. NATURE OF PROBLEM SOLVED**

BALTORO uses the external coupling of neutron and gamma radiation transport data obtained from
the three-dimensional MORSE Monte Carlo code and the one-dimensional discrete ordinates ANISN
code to find the numerical solutions to problems involving (a) the quantity of a radiation-induced
nuclear effect occurring in a neutron field in an infinite homogeneous medium perturbed by a complex
object containing a radiation source and (b) the score from a radiation yielding nuclear effect occurring
in a neutron field in an infinite homogeneous medium perturbed by a complex object containing a
radiation detector.

**5. METHOD OF SOLUTION**

The unperturbed (UN) approximation, the adjoint difference (AD) approximation (volume
coupling), and the surface integral (SI) approximation (boundary coupling) are calculated for problems
of type (a) or (b). The multigroup approximation for the energy dependence and the PLSN
approximation for the angular dependence are applied.

**6. RESTRICTIONS OR LIMITATIONS**

The core size, depending upon the problem, is limited only by the computer available.

A matrix medium should be the infinite homogeneous medium. The probe geometry and the
source or detector energy spectrum must be modeled by the Monte Carlo package. A user-chosen
isotropic effect that is not affecting the transport process can be considered with no time dependence
at points not too close to the perturbed region.

**7. TYPICAL RUNNING TIME**

On the CDC 6600 computer with direct access mass storage, several to a few hundred central
processor seconds may be required depending upon the number of groups and space mesh points,
orders of approximation, number of histories analyzed, and number of points and energetic responses
given.

**8. COMPUTER HARDWARE REQUIREMENTS**

BALTORO requires the CDC computer with the large core device or at least with the direct-addressable disks.

**9. COMPUTER SOFTWARE REQUIREMENTS**

The CYBER version of BALTORO operates under the SCOPE 3.4 system with the FTN compiler.
The CERNCOMPUTER Library routine MEMORY for dynamic reservation of the COMMON field
and the system-library mass storage INPUT/OUTPUT routines (OPENMS, WRITMS, READMS,
AND CLOSMS) for a record-addressable file have been used and may be replaced in a different
system.

**10. REFERENCE**

J. M. Zazula, "BALTORO - A General Purpose Code for Coupling Discrete Ordinates and Monte-Carlo Radiation Transport Calculations," Report No. 1228/AP (1983).

**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 1986.

**KEYWORDS: ** DISCRETE ORDINATES; MONTE CARLO