1. NAME AND TITLE

DTK: One-Dimensional Multigroup Neutron Transport Code System.

DTK was developed from CCC-42/DTF-IV.

2. CONTRIBUTOR

Karlsruhe Nuclear Research Center (GFK), Karlsruhe, West Germany.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

The linear, time-independent, Boltzmann equation for particle transport is solved for the energy, space, and angular dependence of the particle distribution in one-dimensional slabs, cylinders, and spheres. Independent source or eigenvalue (multiplication, time absorption, element concentration, zone thickness or system dimension) problems are solved subject to vacuum, reflective, or periodic boundary conditions.

5. METHOD OF SOLUTION

DTF-IV is designed to solve, by the methods of discrete ordinates (Carlson S_N), the multigroup, one-dimensional (plane, cylinder, sphere) Boltzmann transport equation. Anisotropic scattering is represented by Legendre polynomial expansion of the differential scattering cross section. A complete energy-transfer scattering matrix is allowed for each Legendre component of scattering cross-section matrices.

Energy dependence is treated by the multigroup approximation and angular dependence by a general discrete ordinates approximation. Anisotropic scattering is approximated by a truncated spherical harmonics expansion of the scattering kernel. Within-group scattering and up-scattering (if any) iteration processes are accelerated by system-wide renormalization procedures.

General anisotropic scattering capability is provided in each of the three geometries, up-scattering convergence acceleration is used, an optional group- and point-wise convergence test is available, and a neutron conserving negative flux correction routine is used.

DTK differs from DTF-IV in that: the input has been simplified; a new nonconstant initial source has been built in; a variety of buckling options has been incorporated; Tchebychew extrapolation has been built in for the outer iterations; and capability of passing fluxes from one case to another has been added. If either S_N-order or the number of mesh-points do not agree, DTK is able to interpolate. The Karlsruhe NUSYS cross section code system is not in the package.

PSR-86/GAMLEG provides cross sections for photon transport problems in a form suitable for input to DTK.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

Running time depends on the number of groups, the number of space points, the order of angular approximation, the precision desired and the initial guess.

8. COMPUTER HARDWARE REQUIREMENTS

DTK is operable on the IBM 360/370 computers.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler is required. A nonstandard timing subroutine is included in the package.

10. REFERENCE

C. Gunther, W. Kinnebrock, "The DTK One-Dimensional Transport Program," KFK-Bericht 1381, EURFNR-927 (March 1971).

11. CONTENTS OF CODE PACKAGE

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

12. DATE OF ABSTRACT

February 1974; updated July 1975.

KEYWORDS: DISCRETE ORDINATES; NEUTRON; GAMMA-RAY; ONE-DIMENSION; MULTIGROUP