Evaluated nuclear structure data file. A manual for preparation of data sets

Abstract

This manual describes the organization and structure of the Evaluated Nuclear Structure Data File (ENSDF). This computer-based file is maintained by the National Nuclear Data Center (NNDC) at Brookhaven National Laboratory for the international Nuclear Structure and Decay Data Network. For every mass number (presently, A less than or equal to 263), the Evaluated Nuclear Structure Data File (ENSDF) contains evaluated structure information. For masses A greater than or equal to 45, this information is documented in the Nuclear Data Sheets; for A < 45, ENSDF is based on compilations published in the journal Nuclear Physics. The information in ENSDF is updated by mass chains with a present cycle time of approximately six years. The body of a data set is composed of numeric data records which describe the measured or deduced properties of levels, ..gamma.. rays, ..cap alpha.. particles, etc. These records are associated with the level which decays (for gamma records) or the level which is populated (for beta, ec, or alpha records). Thus, each level record is followed by a group of records describing charged-particle decay into the level and ..gamma..-ray decay out of the level. (WHK)