1. NAME AND TITLE
MACK-IV: Calculation of Nuclear Response Functions from Nuclear Data in ENDF Format.
MACK-IV is an expanded version of PSR-52/MACK.
Argonne National Laboratory, Argonne, Illinois.
Oak Ridge National Laboratory, Oak Ridge, Tennessee.
3. CODING LANGUAGE AND COMPUTER
Fortran IV; IBM 360/370.
4. NATURE OF PROBLEM SOLVED
MACK-IV calculates nuclear response functions important to the neutronics analysis of nuclear and fusion systems. A central part of MACK-IV deals with the calculation of the nuclear response function for nuclear heating more commonly known as the kerma factor. Pointwise and multigroup neutron kerma factors, individual reactions, helium, hydrogen, and tritium production response functions are calculated from any basic nuclear data file in ENDF/B format. MACK-IV processes all reactions in the energy range of 0 to 20 MeV for fissionable and nonfissionable materials. It also calculates the gamma production cross sections and the gamma production energy matrix.
A built-in computational capability permits MACK-IV to calculate the cross sections in the resolved
and unresolved resonance regions from resonance parameters in ENDF/B with an option for Doppler
broadening. All energy pointwise and multigroup data calculated by the code can be punched, printed
and/or written on tape files. Multigroup response functions (e.g., kerma factors, reaction cross
sections, gas production, atomic displacements, etc.) can be output in the format of ``MACK-ACTIVITY-Table'' suitable for direct use with current neutron (and photon) transport codes.
5. METHOD OF SOLUTION
The neutron kerma factor, whose calculation is a central part of MACK-IV, is obtained by
summing over all possible neutron reactions, the product of the reaction cross section and the energy
deposited in the reaction within a negligible distance from the site of collision. The energy deposited
in a reaction is the sum of the kinetic energies imparted to the recoil nucleus and charged particles
emitted. This is calculated from an energy balance that accounts for mass-to-energy conversion and
the energies carried away from the site of collision by neutrons and secondary gamma rays. The
kinetic energy of the neutrons is calculated from the angular or the energy distributions given in
ENDF/B data files. The part of the reaction energy carried away with the gamma rays is calculated
by one of two methods that can be selected by the user. In the first method, the gamma energy is
calculated directly from information in the gamma production files of ENDF/B. In the second method,
the gamma energy is deduced from solving all the nuclear kinematics equations (momentum as well
as energy balance) assuming that direct information on gamma-production is not available. The
calculation of cross sections in the resonance region follows that of the NPTXS module in the AMPX
system. Multigroup kerma factors and cross sections are calculated using an arbitrary weighting
function. The gamma production cross sections are calculated from the gamma production files in
ENDF/B. MACK-IV ensures the consistency in preserving the energy in all phases of the nuclear
6. RESTRICTIONS OR LIMITATIONS
The main restriction is the availability of computer core storage. MACK-IV utilizes the dynamic
storage technique to save on core storage requirements.
7. TYPICAL RUNNING TIME
The problem run time depends mainly on a) the number of resolved resonances, b) the size of the
pointwise energy mesh, c) the method selected for calculating kerma factor, and d) the number of
neutron and gamma energy groups. Typical CPU time on an IBM-370/195 computer is 1-3 min for
non resonance nuclides and 5-10 min for resonance nuclides with 1000 energy points, 171 neutron
groups, and 36 gamma energy groups.
8. COMPUTER HARDWARE REQUIREMENTS
MACK-IV is operable on the IBM 360/370 computers. It is also compatible with the
UNIVAC-1110 and with the CDC-7600 with minor modifications. The central memory storage
requirements vary but are typically within 400 to 800 K bytes. The input/output and temporary files
vary from 4 to 13 depending on the problem.
9. COMPUTER SOFTWARE REQUIREMENTS
A Fortran IV compiler is required.
M. A. Abdou, Y. Gohar, and R. Q. Wright, "MACK-IV, A New Version of MACK: A Program
to Calculate Nuclear Response Functions from Data in ENDF/B Format," ANL/FPP-77-5 (July 1978).
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, and ENDF/B-IV data for Li-7, C, and Be-9.
12. DATE OF ABSTRACT
KEYWORDS: ANISN FORMAT; ENDF FORMAT; KERMA; MULTIGROUP CROSS SECTION PROCESSING