OBNINSK.readme


     Level density parameters for the generalized superfluid models
           (Provided by A. V. Ignatyuk, 28 October 1997)
Contents
--------
The file contains the level density parameters for the Generalized Superfluid 
Model (extension of the Barden-Cooper-Schiefer model). The parameters are 
obtained by fitting the corresponding formulas both to neutron resonance 
spacings and to cumulative numbers of low-lying levels evaluated by the 
Obninsk group. The Generalized Superfluid Model takes into account beside 
the shell and superfluid effects also the collective enhancement of the 
nuclear level density. 
Format
------
FORMAT(I4,A3,I4,F5.1,F7.3,2(F8.3),12F.2,F8.3,I4) is used for data. 
Each row includes the following data: 
Z   :  Atomic number of compound nucleus, 
Sym :  Element symbol of compound nucleus,
A   :  Mass number of compound nucleus, 
Io  :  Spin of the ground state for target nucleus, 
Bn  :  Neutron binding energy of compound nucleus in MeV , 
a   :  Level density parameter of the Fermi gas formula in 1/MeV,
del :  Effective shift of the excitation energy in  MeV,
Do  :  Average resonance spacing in eV,
Uo  :  Excitation energy corresponding to the estimated number of
       low-lying levels in MeV,
No  :  Cumulative number of low-lying levels below Uo .        
Utility code
------------
Code for the level density calculations in the framework of the Generalized 
Superfluid Model is given in the file OBNINSK_BCS.FOR. This file should be 
found in the subdirectory [.OTHER_FILES]. The code can be run on a PC with 
the following command:
  OBNINSK_BCS.EXE < BCS.INP > BCS.OUT        
Input data, BCS.INP, are written in the FORMAT(2X,2(F5.1,1X),8(F7.3,1X)) 
and include the following values: 
Z   :  Atomic number of compound nucleus, 
A   :  Mass number of compound nucleus, 
AAS :  Asymptotic value of the level density parameter in 1/MeV, which
       is usually close to a-as=.073*A +.115 A**.6666,
D0  :  Energy gap parameter in MeV, which is approximately equal to 
       12/A**.3333,
D1  :  Effective shift of the excitation energy in  MeV,
OM  :  Energy of quadrupole vibrations in MeV, which defines the vibrational
       enhancement of the nuclear level density,
BET :  Parameter of quadrupole deformation that defines the rotational 
       enhancement of the nuclear level density,
USTEP and UMAX :  Energy interval and maximal excitation energy in MeV, 
                  for which the level density calculations will be done
       
BCS.OUT repeats the input data + the following information:
the excitation energy, LOG-10 of the state and level densities, the spin
cutoff parameter, the temperature of excited nucleus, the coefficients of
vibrational and rotational enhancement of the level density. An example of
BCS.OUT is given below:
        
  28.0  56.0   4.640  -7.210   1.600    .300    .850    .000    .500  10.000
  ENERGIES LOG.STATES & LEVELS    SIGMA2    TEMPER      QVIBR      QROT 
     .500     1.171      .129     1.279      .725     6.253     1.000
    1.000     2.147      .862     2.078      .844     9.289     1.000
    1.500     2.935     1.497     2.825      .968    13.320     1.000
    2.000     3.404     1.869     3.430     1.109    18.515     1.000
    2.500     3.798     2.188     3.987     1.222    22.508     1.000
    3.000     4.143     2.471     4.511     1.316    25.217     1.000
    3.500     4.456     2.731     5.012     1.398    26.820     1.000
    4.000     4.747     2.976     5.495     1.469    27.565     1.000
    4.500     5.023     3.212     5.961     1.534    27.686     1.000
    5.000     5.290     3.441     6.415     1.592    27.374     1.000
    5.500     5.549     3.667     6.857     1.645    26.774     1.000
    6.000     5.802     3.890     7.289     1.694    25.992     1.000
    6.500     6.052     4.112     7.711     1.739    25.104     1.000
    7.000     6.299     4.332     8.125     1.782    24.162     1.000
    7.500     6.542     4.552     8.531     1.823    23.202     1.000
    8.000     6.784     4.770     8.929     1.861    22.248     1.000
    8.500     7.024     4.989     9.320     1.898    21.316     1.000
    9.000     7.262     5.206     9.704     1.932    20.416     1.000
    9.500     7.498     5.424    10.082     1.966    19.554     1.000
   10.000     7.733     5.640    10.454     1.998    18.734     1.000
Stop - Program terminated.