BUDAPEST.readme
Budapest Discrete Level Schemes Library
(Provided by G. Molnar, 15 September 1997)
***********************************************
Contents
--------
1. BUDAPEST_LEVELS.DAT - the actual library, ASCII text file with
132-character lines, about 5 Mbyte size;
first version: 16 November 1996, last modified: 15 September 1997
2. BUDAPEST_CUMULATIVE.DAT - ASCII table of the fitted cumulative numbers,
cutoff energies and level density parameters;
first version: 16 November 1996, last modified: 15 September 1997
3. BUDAPEST.README - describes the library's format and contains an
illustrative example (this file).
Background
----------
The Budapest Discrete Level Schemes Library has been created at
the Institute of Isotopes, Budapest, using the 23 February 1996 version
of the Evaluated Nuclear Structure Data File ENSDF as input data source.
The library contains data for 2,585 nuclei: 96,834 levels and 105,423
gamma rays with their characteristics such as energy, spin, parity,
half-life, as well as gamma-ray placements and branching percentages,
respectively.
The major steps are outlined below:
The adopted discrete nuclear levels and gamma-ray transitions have
been retrieved on line, using the program NUDAT.
The retrieved ENSDF data have been filtered for errors and converted
into a library file in the extended Bologna format.
The cutoff energy, Umax, and the cumulative number, Nm, of levels up
to this energy have been determined from exponential fits to the
staircase plots for those 1,277 nuclei for which at least 10 levels
were known and have been included in the file as a cutoff value up
to which the discrete level scheme is complete.
A second energy cutoff, Uc, corresponding to the upper energy limit
of levels characterized by an unique spin and parity has been determined
for all nuclei on the basis of ENSDF data alone.
Truncations mandated by the adopted format:
As the final levels are identified by their two-digit integer serial
number, the sets of gammas had to be truncated to keep the serial number
of final levels below 100 for each individual nuclide. (There is no
limit to the number of initial levels, however.)
For branching percentages also only two digit integer numbers (100% is
given as 00) are allowed. Therefore all branching values had to be
rounded to integers, and gammas with branchings below 0.5% had to be
deleted. The truncation has affected 2,922 gammas, reducing their total
number to 105,423 gamma rays.
Limitations on choices of level parameters:
Level spins and parities have been included in the file only if a single
value was assigned at least tentatively by the ENSDF evaluators. In
cases of multiple spin choices tentative values have been inferred
according to the following rule: out of two alternative spins the higher
value, out of three the middle value has been adopted. For the rest of
cases no spin values were given at all, and no attempts were made to
infer parities either. Separate flags mark uncertain or undefined spin
and parity, respectively.
The extended Bologna format also allows the inclusion of half-lives.
Those excited levels with half-lives greater than one second have been
flagged as isomers.
The cutoff numbers Nm, Nc facilitate the truncation of input string
whenever necessary.
Format of file BUDAPEST_LEVELS.DAT
----------------------------------
IAEA Project RIPL - Phase I (1994/97)
DISCRETE LEVEL SCHEMES SUBLIBRARY - Version 16 November 1996
Prepared by: J. Ostor, T. Belgya and G. Molnar,
Institute of Isotopes, Budapest, Hungary
Format: ASCII, 132 characters per line
Data format: Extended version of original Bologna format
by G. Reffo et al. (ENEA Bologna, Italy)
1. First line
Number of levels (format I5); 18 blanks; mass, charge, 0 (format 3I3);
40 characters for bibliographic information
2. Second line - new!
Level number for cutoff Umax,
level number for spin/parity cutoff Uc (blank if not available,
format 2I3); 23 blanks; 0 (format I3)
3. All other lines
Col 1: * flag = uncertain parity (blank otherwise)
Col 2-4: parity (+1 or -1 or blank, format I3)
Col 5-13: level energy in MeV (format F8.5)
Col 14-20: spin (format F8.5)
Col 21: X flag = isomeric level
Col 22: * flag = uncertain energy - not used!
Col 23: * flag = uncertain spin
Col 24-32: mass, charge, level number (format 3I3)
Col 33-112: data for 18 gamma decay events (format 18I4;
first 2 digits = number of final level, second 2 digits = branching
percentage /100 percent given as 00)
Col 113-119 : level half-life in seconds (scientific format)
..........................................................................
Example: Co-60
286 60 27 0*** FROM NUDAT 1996 FEB 23
10 10 0
1 0 5 60 27 1 ... 4.017E7
1 .05859 2 X 60 27 2 100 ... 6.28E2
1 .2772 4 60 27 3
1 .2884 3 60 27 4 200
1 .43571 5 60 27 5 139 361
1 .5062 3 60 27 6 299 4 1
1 .54282 2 60 27 7 200
1 .61455 3 60 27 8 296 3 4
1 .7388 1 60 27 9 259 741
1 .78571 4 60 27 10 153 444 5 2 8 1 ... 3.2E-12
* .94 * 60 27 11
* 1.00391 * 60 27 12 249 323 4 2 726
* 1.0058 4 60 27 13 1 6 440 85110 2
* 1.13198 * 60 27 14 900
* 1 1.1507 * 60 27 15 400
1 1.20783 5 60 27 16 129 371
1 1.21645 6 60 27 17 100 ... 2.8E-13
...
...........................................................................
Format of file BUDAPEST_CUMULATIVE.DAT
--------------------------------------
IAEA Project RIPL - Phase I (1994/97)
Source: T. Belgya, G. Molnar, B. Fazekas and J. Ostor,
"Histogram plots and cutoff energies for nuclear discrete levels"
Report INDC(NDS)-367 (IAEA Vienna, 1997)
Format: ASCII table, 132 characters per line
Headings:
A - atomic mass number
Z - atomic charge number
n - total number of known levels, including ground state
Nc - complete spin information cutoff level number, corresponds to Uc
Nm - accepted cumulative number of levels, corresponds to Umax
Uc - complete spin information cutoff energy (in MeV units)
Umax - fitted complete level scheme cutoff energy (in MeV units)
* means Umax>Sn or Sp, the neutron (proton) separation energy
U0 - fitted "backshift energy" (in MeV units)
T - fitted "nuclear temperature" (in MeV units)
Chi^2 - chi-square
The parameters Umax, U0 and T are given for both the accepted local
minimum and the absolute minimum of chi-square separately
(# marks cases where the two minima are different).
A word of caution: the U0 and T parameters, obtained in a simplified
model, should not be taken as realistic level density parameters.