1. NAME AND TITLE
ERINNI: Optical Model Calculation of Multiple Cascading Particle Emissions.
Centro di Calcolo del CNEN, Bologna, Italy, through the NEA Data Bank, Gif-sur-Yvette, France.
3. CODING LANGUAGE AND COMPUTER
Fortran IV; IBM 360/370.
4. NATURE OF PROBLEM SOLVED
ERINNI offers an optical model calculation of multiple cascading particle emissions. It computes
42 cross sections for each incident energy representing all possible compound nucleus processes of
types (x,a), (x,ab), and (x,abc) where x can be indifferently a neutron, proton, or alpha particle; a and
b can be a neutron, a proton, an alpha or gamma particle; and c can be a neutron or a gamma particle.
ERINNI is particularly useful for extensive cross section calculations such as those in the range of
reactor calculation needs.
5. METHOD OF SOLUTION
The scattering amplitudes and the other optical model quantities are calculated in accordance with spherical local potentials by the usual methods.
Parameters are needed for 10 residual nuclei, hence particular care was devoted to reducing the
input procedure. The table for pairing energies, the Mass excess table, the level density data
systematics, and the optical model parameter sets most frequently used in literature are all incorporated
in the program and can be used optionally as an alternative to more specific choices of data.
6. RESTRICTIONS OR LIMITATIONS
No width fluctuation is included because it is devised for high energy calculations.
7. TYPICAL RUNNING TIME
The OECD NEA Data Bank executed the test case included in the package on an IBM 3084Q
computer in 375 seconds of CPU time. Computing time was reduced because the various optical
model transmission coefficients and consequent decay probabilities at a given incident energy, when
they are calculated within appropriately narrow energy intervals, lend themselves to interpolation.
8. COMPUTER HARDWARE REQUIREMENTS
ERINNI is operable on the IBM 360/370 computers. 240 kbytes of fast core memory is required
if used together with the overlay structure.
9. COMPUTER SOFTWARE REQUIREMENTS
A Fortran IV compiler is required.
F. Fabbri and G. Reffo, "ERINNI: An Optical Model Fortran IV Code for the Calculation of
Multiple Cascading Particle Emissions," RT/FI(77)4 (April 1977).
11. CONTENTS OF CODE PACKAGE
Included are the referenced document and one (360KB) DOS diskette which contains the source
code and sample problem input.
12. DATE OF ABSTRACT
KEYWORD: NUCLEAR MODELS