1. NAME AND TITLE
MECC-7: Medium-Energy Intranuclear Cascade Code System.
MECC-7 Cascade data generator.
I4C: Cascade Data Analysis, combined form of 4 routines: Analysis I, Analysis II, Evaporation, and Angular Momentum.
NUCON: CS update code.
CONV: BCD-to-binary converter for data libraries.
ANG: Angular momentum distribution calculation.
Non-standard library subroutines.
CS: Nuclear Configuration Data and Cross Sections for MECC-7.
ET: Evaporation Table for EVAP.
Originally packaged as MECC-3 (1971), MECC-7 is the latest in this series of ORNL
intranuclear cascade code development.
Oak Ridge National Laboratory, Oak Ridge, Tennessee.
3. CODING LANGUAGE AND COMPUTER
FORTRAN IV; IBM 360/75/91. Non-standard library subroutines are in Assembly Language.
4. NATURE OF PROBLEM SOLVED
MECC-7 calculates the results of nuclear reactions caused by a medium-high energy particle colliding with a nucleus. The incident particles may be protons or neutrons with energies from about 100 to 2500 MeV or charged pions with energies from about 100 to 1500 MeV. Target nuclei may be any element heavier than carbon. MECC-7 writes a history tape containing data on the properties of the particles escaping from the nucleus as a result of the particle-nucleus collision. The data consist of the type of escaping particles, their energies, and angles of emission.
I4C utilizes the data on the MECC-7 history tape to calculate particle multiplicities and various
cross sections, such as the nonelastic cross section or the doubly-differential cross section for
energy-angle correlated distributions. I4C also carries the nuclear reaction through an additional
phase, that of evaporation, and calculates evaporation residual nuclei (radiochemical) cross sections
and the particle multiplicities and energy spectra of particles "boiled off" from the nucleus after the
cascade has stopped.
5. METHOD OF SOLUTION
The code system is based on the assumption that nuclear reactions involving high-energy
particles can be described in terms of particle-particle collisions within the nucleus. The life history
of each individual particle is traced as the incident particle, and the subsequent generations of
particles involved in collisions, wind their way through the nucleus. The point of collision, the type
of collision, the momentum of the struck nucleon, and the scattering angles for each collision are
determined by statistical sampling techniques. Free-particle experimental data are used whenever
cross-section data are required. Cross sections and distributions resulting from the nuclear reaction
are calculated in I4C by taking the average value of many results.
6. RESTRICTIONS OR LIMITATIONS
There are no known restrictions implied by storage allocation. Target nuclei may be any
element from 4He to 239Pu. Incident particle energies must be 1 MeV or greater. Incident nucleon
energies must be less than 3500 MeV, and incident pion energies must be less than 2500 MeV. The
results are expected to be valid only over the ranges described in section 4. The maximum possible
number of incident particle histories is 999,999.
7. TYPICAL RUNNING TIME
The approximate running times on the IBM 360/91 per 1000 incident particles ranged from
0.26 minutes for a 1-GeV particle on oxygen to 3.3 minutes for the same energy particle on lead,
and from 0.4 minutes for a 2.5-GeV particle on oxygen to 6.2 minutes for the same energy particle
on lead. The I4C analysis with all options takes approximately 1/5 of the MECC-7 running time.
8. COMPUTER HARDWARE REQUIREMENTS
The codes were designed for the IBM 360/75/91 with standard I-O and a maximum of 6 tape
units or direct access devices. Maximum core size required ~ 1020K.
9. COMPUTER SOFTWARE REQUIREMENTS
The packaged codes were run on the IBM 360/75/91 Operating System using OS-360 FORTRAN H Compiler.
I4C uses the overlay feature and was compiled with OPT = 2.
H. W. Bertini, M. P. Guthrie, and O. W. Hermann, "Instructions for the Operation of Codes Associated with MECC-7, A Preliminary Version of an Intranuclear-Cascade Calculation for Nuclear Reactions," ORNL-4564 (May 1971).
R. L. Hahn and O. W. Hermann, "Inclusion of Fission and Charged-Particle Emission in Calculations of Nuclear Reactions; Computed Energies, Angles, and Ranges of Recoil Nuclei," ORNL-TM-3179 (April 1971).
M. P. Guthrie, "EVAP-4: Another Modification of a Code to Calculate Particle Evaporation from Excited Compound Nuclei," ORNL-TM-3119 (September 1970).
Contents of MECC Primary Output Tape, informal notes.
Contents of Nuclear Configuration Tape, informal notes (March 1969).
H. W. Bertini and M. P. Guthrie, "Results from Medium-Energy Intranuclear-Cascade Calculation," Nucl. Phys., Al69, (1971) 670-672.
H. W. Bertini, "Nonelastic Interactions of Nucleons and pi Mesons with Complex Nuclei at Energies Below 3 GeV," Phys. Rev. C, Vol. 6, No. 2 (August 1972), 631-659.
H. W. Bertini, "Intranuclear-Cascade Calculation of the Secondary Nucleon Spectra from Nucleon-Nucleus Interactions in the Energy Range 340 to 2900 MeV and Comparisons with Experiment," Phys. Rev., Vol. 188, No. 4 (December 1969) 1711-1730.
H. W. Bertini, "Low-Energy Intranuclear Cascade Calculation," Phys. Rev., Vol. 138, No. 7AB, AB2 (June 1965).
H. W. Bertini, "Low-Energy Intranuclear Cascade Calculation," Phys. Rev., Vol. 131, No. 4
(August 1963) 1801-1821.
11. CONTENTS OF CODE PACKAGE
Included are the referenced documents and one (1.2MB) DOS diskette which contains the
source codes, data libraries, and sample problem input and output.
12. DATE OF ABSTRACT
February 1972; revised December 1984.
KEYWORD: INTRANUCLEAR CASCADE