GEF-2023-3-3

GEF 2023/3.3

General description of fission observables,
released on August 2, 2024.

Short characterisation of GEF 2023/3.3:

Compared to GEF 2023/3.2, the following modification have been applied:
- For a better reproduction of fast-neutron-induced fission of 238U, the peak at Z = 50 in the contribution of the proton shell to the standard 1 fission mode was flattended.
- The onset of the suppression of the standard 1 fission mode was smeared out.
- A small deformation of the heavy fragment in the standard 1 fission mode due to the neck was introduced and adjusted to reproduce the prompt-neutron multiplicities of 235U(nth,f) and 252Cf(sf).
- The transition in the level density from const. temp. to Fermi-gas in EVI was corrected.

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.
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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 (32-bit/64-bit), considers only long-lived isomers.
Version with nuclear properties from NUBASE2016 (32-bit/64-bit), considers all known isomers.

Make sure that the binary file GEF is executable.
Enter ./GEF32 or ./GEF64 in a command window.
Answer the input dialogue.
Output is written to file /out/... .dat.

Remark: The problem with the 64-bit compiler that had been mentioned on this place is solved.

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

An extended version of GEF-2023/3.3 that includes delayed processes (output of delayed-neutron multiplicities, delayed-neutron emitters, cumulative fission-fragment yields in ENDF format) is available here. It provides also an option for producing random files of fission-fragment yields in ENDF format.

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

Additional data

List of fission barriers