Library Summary
Version V of the ENDF/B data file was released in June 1979, which was subsequently named Version V.0. Version V.1 was released in 1983 and Version V.2 was released in January 1985. The description of the formats and procedures are documented in BNL-NCS-50496, edition 2, 1983 revision.
The library is structured according to tapes, with the following allocations:
- 509 - fission product yields
- 510 - fission product yields
- 511 - standard materials
- 514 - actinides
- 521 - actinides
- 522 - actinides
- 531 - dosimetry
- 532 - activation
- 533 - neutron cross-sections only, gas production file
- 541-546 - fission product file
- 564 - special purpose activation (on 532)
- 565 - special purpose actinide (on 521 + 522)
- 566 - special purpoe fission product (on 541 - 546)
- 567 - update of 509
- 568 - update of 510, 511, 514
Format Changes
The File 1 changes included the following. The HEAD card of MT = 451 was changed. NXC, the number of dictionary entries, had been moved to the sixth field of the Hollerith LIST record of MT = 451. Field 5 now contained NLIB, the library identifier, and field 6 now contained NMOD, the material modification number. Following the HEAD card of MT = 451 is a new CONT card, which contains information about the excitation energy, stability, state number, and isomeric state number of the target nucleus. In the LIST record of MT = 451, the LDD and LFP flags have been abolished. The number of dictionary entries, NXC, is now in the sixth field of the first card in this LIST record. The fourth field on each dictionary card in MT = 451 is now used to indicate the modification status (MOD) for the section described by the card. Radioactive decay data (MT = 453 and 457) have been removed from File 1. Entirely new formats have been devised and the radioactive decay data is given in MF = 8, MT = 457. The fission product yields section (MT = 44) has been removed from File 1. Fission product yield information is now given in File 8 using new formats. A new section to describe energy release in fission (MF = 1, MT = 458) has been implemented.
The File 2 changes included the restriction that the Reich-Moore resonance parameter representation is no longer permitted in ENDF/B, only in ENDF/A.
The File 3 changes included the following. The total "gas production" MT's have been defined for H(203), D(204), T(205), 3He(206) and 4He(207). The non-elastic cross section (MT = 3) is now optional and no longer required since total gamma ray production must be entered in File 13 and never as multiplicities in File 12.
The file 4 changes include a simplified format using a new flag, LI, has been introduced to indicate that all angular distributions for an MT are all isotropic.
The File 5 changes include only the distribution laws for LF = 1, 5, 7, 9 and 11 are now allowed. LF = 11 is a new format for an energy dependent Watt spectrum.
The File 8 changes include the following. Information may be given for any MT specifying a reaction in which the end product is radioactive. The MT section contains information about the end product and how it decays. Files 9 and 10 may be used to give the cross section for the production of the end product. Fission product yield information is given under MT = 454 and 459. The format has been modified to include the 1 σ uncertainty of the yields. MT = 454 is for independent yields and MT = 459 is for the cumulative yields. The spontaneous radioactive decay data is given in MT = 457. This is an entirely new format.
The file 9 and 10 changes include the following. Isomer production is described in the new File 9 or File 10. In File 9, the cross sections are obtained by use of multiplicities. In File 10, the absolute cross sections are given.
The File 17 and 18 changes are the following. Formats for time dependent photon production data files have been defined. They may be used in ENDF/A only.
The Files 19, 20, 21 and 22 changes are the electron production data files have been implemented.
The Files 31, 32 and 33 changes are the formats for data covariance files first introduced in Version IV have been extensively modified and expanded. They are now included in this document for the first time. Twenty-four materials and reactions are available in ENDF-V format containing covariance files.
The Department of Energy put restrictions on the distribution of the library for the first time. This version was the first to have the evaluation of standards completed in advance of the evaluation of other materials.
-- Adapted from the ENDF/B-VII format manual, Appendix I "Historic Perspective", By Norman Holden.