GEF-2020-1-2

GEF 2020/1.2

General description of fission observables. Released December 4, 2020.
Last update January 4, 2021.
Update: May 29, 2021. (Complete output of mass-dependent gamma multiplicities.)

Short characterisation of GEF 2020/1.2:

Compared to GEF 2020/1.1, the description of asymmetric fission in the pre-actinides has been revised. The carefully measured energy dependence of the mass yields in 205Bi(p,f) [Swinton-Bland et al., Phys. Rev. C 102 (2020) 054611] is better reproduced by a reduction of the macroscopic binding energy on the asymmetric fission path. Other systems in the pre-actinides are less well described, in particular at low excitation energies.

Note that the parameters of GEF 2020/1.2 might still slightly be modified.

Mass yields of U235T in comparison with JEFF 3.3

The mass distribution of 235U(nth,f) from GEF-2019/1.1 (red points) in comparison with the JEFF 3.3 evalution (black symbols with error bars). The calculated contributions from different fission channels are traced in green. 10 million events have been calculated.

An extended version of GEF-2020/1.2that includes delayed processes (output of delayed-neutron multiplicities, delayed-neutron emitters, cumulative fission-fragment yields in ENDF format) is available on demand. It provides also an option for producing random files of fission-fragment yields in ENDF format.

We are happy about any feed-back (mail to schmidt-erzhausen<at>t_online.de). This helps to correct errors, to improve the quality of the model and to better respond to the needs and preferences of the users.

Use of the GEF code is subject to the GNU GENERAL PUBLIC LICENSE agreement that you find here: <License>.

Stand-alone version (Monte-Carlo method)

The stand-alone version of the GEF code is written in FreeBASIC (a). The FreeBASIC compiler produces binary code from the same source on Windows (b) and on Linux. The executable uses the C library. For the Windows version, a GUI is provided, written in JustBasic (c). The Windows version runs also on Linux with Wine (d). The Windows version runs also on OS X (e) with Wine (d).

a) FreeBASIC is available from http://www.freebasic.net/ with no cost.
b) Windows is either a registered trademark or a trademark of Microsoft Corporation in the United States and/or other countries.
c) JustBasic is available from http://www.justbasic.com/ with no cost.
d) Wine is a windows compatibility layer for Linux and Mac OS X (http://www.winehq.org/).
e) OS X is a trademark of Apple Inc., registered in the U.S. and other countries.

Quick start on Windows:

Download the binaries (that includes some additional files).

Version with nuclear properties from JEFF-3.3 (considers only long-lived isomers)
Version with nuclear properties from NUBASE2016 (considers all known isomers)

Start GEF.bat in a command window.
Fill in the input mask of the graphical user interface and start the calculation.
Output is written to file \out\... .dat.

Quick start on Linux:

Download the binaries.

Version with nuclear properties from JEFF-3.3 (considers only long-lived isomers)
Version with nuclear properties from NUBASE2016 (considers all known isomers)

Make sure that the binary file GEF is executable.
Enter ./GEF in a command window.
Answer the input dialogue.
Output is written to file /out/... .dat.

Windows version

Input mask of the graphical user interface:

For Windows and Linux

Complete package

Documentation

Readme file (Technical information, list of relevant publications)
JEFF-Report 24, part I (Comprehensive documentation of the GEF model.)
JEFF-Report 24, part II (Technical information on the GEF code.)

Source (for Windows and Linux)

Source files

Data

Input files for extended input options

Distribution of entrance energies (example)
List of input parameters (example)
See Readme file for more detailed information.

Output

Data tables in XML-assisted format (example)
List-mode file (example) (short sample of most complete event list)
Raw data for the multi-variate distribution of fission-fragment yields from calculations with perturbed parameters (example)
See Readme file for more detailed information.

You may consider using the Windows version of GEF on Linux with Wine in order to profit from the more comfortable input handling offered by the graphical user interface. This option may also solve problems of missing libraries under Linux.

Subroutine (Folding method)

The subroutine aims for being used in combination with other nuclear-reaction codes. For a given fissioning nucleus with excitation energy E* and angular momentum I it calculates complete distributions of a number of fission observables before emission of prompt neutrons and prompt gamma radiation with the GEF model.

Documentation

Technical description of the subroutine

FreeBASIC version

In preparation

FORTRAN version

In preparation