|Program name||Package id||Status||Status date|
|Package ID||Orig. computer||Test computer|
|NEA-1344/01||IBM 3090||DEC VAX 8810|
Within the International Evaluation Cooperation, four energy group structures for multigroup cross section libraries were defined and adopted. The main purpose is to facilitate the inter-laboratory benchmarking of the evaluated files: ENDF/B-VI, JEF-2, JENDL-3. These group structures are:
VITAMIN-J, a 175 neutron and 42 photon group structure aimed at fission and fusion reactor shielding and for fusion blanket shielding (based on VITAMIN-J and -D group structures).
XMAS, a 172 neutron group structure, based on group structures formerly used with APOLLO and WIMS. This group structure is aimed at thermal and intermediate spectra cell calculations.
ECCO-33, a 33 neutron group structure forming a subset of the VITAMIN-J structure. It is aimed at benchmarking fast reactor criticality calculations.
ECCO-2000, a 1968 neutron fine group structure based on a lethargy grid of 1/120. It contains all the energy boundaries of the group structures VITAMIN-J, XMAS, and ECCO-33.
A computer program is provided for producing a weighting spectrum for group averaging purposes. This spectrum is the one adopted for the VITAMIN-J group cross section libraries and consists of
temperature dependent thermal Maxwellian
1/E slowing down spectrum
The computer produces a table which is linearly interpolable to a specified tolerance.
|Package ID||Status date||Status|
|NEA-1344/01||15-JAN-1991||Tested at NEADB|
|Package ID||Computer language|
|File name||File description||Records|
|NEA1344_01.002||VITAMIN-J (175) Neutron Group Boundaries||31|
|NEA1344_01.003||VITAMIN-J (42) Gamma Group Boundaries||9|
|NEA1344_01.004||XMAS (172) Neutron Group Boundaries||30|
|NEA1344_01.005||ECCO-33 (33) Neutron Group Boundaries||7|
|NEA1344_01.006||ECCO-2000 (1968) Neutron Group Boundaries||330|
|NEA1344_01.007||VITAMIN-J Spectrum Generation Program||459|
|NEA1344_01.008||Dummy plotting routines||22|
|NEA1344_01.009||JCL for running spectrum generation program||23|
|NEA1344_01.010||Sample Problem output spectra||1013|
|NEA1344_01.011||Sample Problem printed output||10|
|NEA1344_01.012||Group Structures Comparison||1976|
Keywords: group constants, neutrons, photons, spectra.