Directory: densities/fission/
File:      fis-barrier-etfsi.readme (January 15, 2002)
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			fis-barrier-etfsi.dat

    Compilation of fission barriers and saddle point deformations
		       based on the ETFSI model
	     (provided by S. Goriely on January 15, 2002)
    **************************************************************

    LARGE-SCALE FISSION-BARRIER CALCULATIONS WITH THE ETFSI METHOD

			 A. Mamdouh, M. Rayet
	       Universite Libre de Bruxelles (Belgium)
			      M. Pearson
	       Universite de Montreal, Quebec (Canada)
			      F. Tondeur
	 Institut Superieur Industriel de Bruxelles (Belgium)


Content
--------
Predictions of the fission barriers and saddle point deformations
obtained within the Extended Thomas-Fermi plus Strutinsky Integral
(ETFSI) method. The ETFSI approach is a semi-classical approximation
to the Hartree-Fock method in which the shell corrections are
calculated with the 'integral' version of the Strutinsky theorem. BCS
corrections are added with a delta-pairing force.  The fission
barriers are derived with the SkSC4 Skyrme force on which the ETFSI-1
mass formula is based. The experimental primary barriers can be
reproduced within 1.5 MeV (except for the elements with Z < 87 having
barriers above 10 MeV).

The present ETFSI compilation includes 2301 nuclei with Z=78 through
120.  Their masses range from slightly neutron deficient to very
neutron rich nuclei (close to or up to the calculated neutron drip
line), up to A = 318. This compilation contains the nuclei considered
in [1], for which experimental barriers are known, and a slightly
extended version of the set published in [2]. Also included are the
experimental fission barriers compiled in [1] and those originating
principally from [3].

For each nucleus a maximum of two barriers are given, one "inner" and
one "outer". They correspond to the highest saddle point among the
"slightly" and the "strongly" deformed ones. Those two groups of
saddle points correspond to well separated values of the elongation
parameter c, cin and cout (see below).  In most cases cin < 1.6 and
cout > 1.6 (in some cases 1.5 <cout <1.6).

In addition to the calculated inner and outer barriers, the
deformation parameters at the corresponding saddle points are
included. The nuclear shapes are limited to axially symmetrical
deformations. These are described by the so-called Brack
parametrization (c,h,alpha) where c is the elongation parameter
(c<1,=1 and >1 for oblate, spherical and prolate shapes, resp.) and h
is related to the "necking" of the nuclear surface. The shapes
corresponding to different regions of the (c,h) plane are described in
detail in [1]. The parameter alpha measures the left-right asymmetry
(alpha = 0 for symmetric shapes). The asymmetry parameters ain and
aout listed in the file refer not to alpha but to the quantity
alphatilda defined in [1] as alpha*c**3. In term of this quantity, the
mass ratio of the two fission fragments is roughly given by
(1+3/8*alphatilda)/(1-3/8*alphatilda).

All the calculated barriers have deformation parameters within the
following domain: 1.00<c<2.36, -0.26<h<+0.22, 0<=alphatilda<0.75 .


Format
------
Each record of the file contains:

   Z   : charge number
   A   : mass number
   El  : element symbol
   cin : c of the inner barrier
   hin : h of the inner barrier
   ain : alphatilda of the inner barrier
   Bin : inner barrier in MeV
   Bexp: inner experimental barrier in MeV
   cout: c of the outer barrier
   hout: h of the outer barrier
   aout: alphatilda of the outer barrier
   Bout: outer barrier in MeV
   Bexp: outer experimental barrier in MeV

The corresponding FORTRAN format is (2i4,1x,a2,1x,10f9.2)


References
----------
[1] A. Mamdouh, J. M. Pearson, M. Rayet and F.Tondeur (1998), Nucl. Phys.  A644,
    389.
[2] A. Mamdouh, J. M. Pearson, M. Rayet and F.Tondeur (2001), Nucl. Phys. A679,
    337.
[3] G. N. Smirenkin (1993) IAEA-Report INDC(CCP)-359.