Nuclear stucture data refer to the properties of single nuclei, as opposed to reaction data which deals with the properties of a nucleus interacting with radiation or another nucleus.
Numerical data related to nuclear structure are available in the ENSDF and NUDAT databases, and bibliographic information on nuclear structure is found in the NSR database.
The International Nuclear Structure and Decay Data (NSDD) Network is organised under the auspices of the International Atomic Energy Agency, and co-ordinated by the National Nuclear Data Center (NNDC) at the Brookhaven National Laboratory, US. The NSDD Network is responsible for the evaluation of all the mass-chains on a continual basis. A mass-chain is formed by all the nuclides of the same mass and different chemical elements. Each of the members of the network has a permanent assignment of mass-chains depending on the number of evaluators, their research interests, or special expertise in a particular mass region. Evaluations produced by the NSDD Network are stored in the Evaluated Nuclear Structure Data File (ENSDF) database. Links to data centres in the NSDD Network is available from NNDC
ENSDF contains evaluated experimental data summarizing the present knowledge on the structure and decay of nuclei. It contains information on nuclear level properties, radiations, radioactive decay, and reaction data for all known nuclides. For masses A ≥ 45, this information is documented in the Nuclear Data Sheets; for A < 45 ENSDF is based on compilations published in the journal Nuclear Physics.
If there are gaps in experimental data, they are not filled with theoretical or nuclear model calculations. While the emphasis is on experimental data, the evaluations do use well-founded systematics or theory.
The Evaluated Nuclear Structure Data File is made up of a collection of "data sets" which present one of the following kinds of information:
The data sets in ENSDF are organised by their mass number. Within a mass number the data sets are of two kinds:
Data sets (ii) i.e., for a given nucleus (Z-value), consist of the following:
If the is more than one data set of type (1) or (2) for a given nucleus, then an adopted data set is required for that nucleus. If there is only one data set for a given nucleus, then that set is assumed also to present the adopted properties for that nucleus.
A full and detailed description of the ENSDF format is provided in:
"Evaluated Nuclear Structure Data File - A Manual for Preparation of Data Sets", J.K.Tulli, Feb 2001, BNL-NCS-51655-01/02-Rev
This mode of access provides an easy way to make simple searches of the ENSDF database. Simply enter a mass number (1 through 266) or a nuclide in the form ZZAAA (e.g.,235U) or ZZ-AAA (e.g., U-235).
A number of analysis and utility codes for use with ENSDF data are available from NNDC. Instructions on retrieving the codes from NNDC are described in "ENSDF Analysis and Checking Codes" (Postscript) or "ENSDF Analysis and Checking Codes"
The NUDAT database contains data extracted from several databases maintained at the National Nuclear Data Center (NNDC). The table below lists the type of data contained in NUDAT, and their origin:
|Adopted levels||-||Adopted nuclear level information from ENSDF|
|Adopted gammas||-||Adopted gamma rays from levels in ENSDF|
|Adopted levels and gammas||-||Levels and gamma ray information combined|
|Ground and Metastable state properties||-||Properties of ground/metastable states from the Wallet Cards|
|Decay Radiations||-||ENSDF decay radiations from decay data processed by the code RADLST|
|Thermal Neutron Data and Resonance Integrals||-||Thermal neutron cross sections and resonance integrals from BNL325|
This mode of access provides an easy way to make simple searches of the NUDAT database. The opening screen invites the user to select the type of data desired (selected from the list of data types shown above). For all data types the chemical symbol (or atomic number) and mass number are offered as search parameters. The other search parameters available are dependent on the data type. A full desciption of possible search criteria, together with examples, can be found on the web page "The NuDat2 Description".
The AME2003 atomic mass evaluation" is presented here in the form of four files:
The format of these data files are described in each of their headers (first 39 records). Note that the format is not identical to the 1993 and 1995 files.
See also the web page http://www.nndc.bnl.gov/amdc/.
The table of masses and the table of nuclear reaction and separation energies resulting from the evaluation published in:
"The 1995 Update to the Atomic Mass Evaluation" (Ame'95), G. Audi and A.H. Wapstra, Nuclear Physics A595 (1995) P409-480
are made available in electronic format.
Most readers can best use the set of recommended tables (labelled with `rmd') whereas the more specialized user could with benefit analyze the second set (with label `exp').
The first file, mass_rmd.mas95, contains the table of masses as printed in the reference above, plus the binding energies, the beta-decay energies and the atomic masses.
The next two files correspond to the table of reaction and separation energies (cf. "The 1993 Atomic Mass Evaluation", part II) in two parts of 6 entries each:
rct1_rmd.mas95 for S2n, S2p, Q(a), Q(2B), Q(ep), Q(B-n)
rct2_rmd.mas95 for Sn, Sp, Q(4B), Q(d,a), Q(p,a), Q(n,a)
The last three files with names mass_exp.mas95, rct1_exp.mas95 and rct2_exp.mas95 are identical to the first three files except for the values resulting from the use of the few deviating experimental data, listed in Table~B of Ame'93 and updated in Table~IV-a of Ame'95.
Values in these files are exact (unrounded) copy of the published ones.
|rct1_rmd.mas95||Recommended reaction energies, table 1|
|rct2_rmd.mas95||Recommended reaction energies, table 2|
|rct1_exp.mas95||Experimental reaction energies, table 1|
|rct2_exp.mas95||Experimental reaction energies, table 2|
Last reviewed: 23 September 2010