NEA-1864 GEF.
GEF, Code for Simulation of Nuclear Fission Process
NAME OR DESIGNATION OF PROGRAM, COMPUTER, DESCRIPTION OF PROGRAM OR FUNCTION, METHODS, RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM, TYPICAL RUNNING TIME, RELATED AND AUXILIARY PROGRAMS, STATUS, REFERENCES, HARDWARE REQUIREMENTS, LANGUAGE, SOFTWARE REQUIREMENTS, OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS, NAME AND ESTABLISHMENT OF AUTHORS, MATERIAL, CATEGORIES
[ top ]
[ top ]
To submit a request, click below on the link of the version you wish to order.
Only liaison officers are authorised to submit online requests. Rules for requesters are
available here.
| Program name | Package id | Status | Status date |
|---|---|---|---|
| GEF | NEA-1864/04 | Arrived | 20-JUN-2012 |
Machines used:
| Package ID | Orig. computer | Test computer |
|---|---|---|
| NEA-1864/04 | Linux-based PC,PC Windows |
[ top ]
3. DESCRIPTION OF PROGRAM OR FUNCTION
GEF is a computer code for the simulation of the nuclear fission process. The GEF code calculates pre-neutron and post-neutron fission-fragment nuclide yields, angular-momentum distributions, isomeric yields, prompt-neutron yields and prompt-neutron spectra, prompt-gamma spectra and several other quantities for a wide range of fissioning nuclei from polonium to seaborgium in spontaneous fission and neutron-induced fission. The result refers to first-chance fission. Output is provided as tables and as values of fission observables on an event-by-event basis.
Specific features of the GEF code:
- The mass division and the charge polarisation are calculated assuming a statistical population of states in the fission valleys at freeze-out. The freeze-out time considers the influence of fission dynamics and is not the same for the different collective variables.
- The separability principle [1] governs the interplay of macroscopic and microscopic effects.
- Four fission channels are considered. The strengths of the shells in the fission valleys are identical for all fissioning systems. The mean positions of the heavy fragments in the asymmetric fission channels are essentially constant in atomic number, as suggested by experimental data [2].
- The stiffness of the macroscopic potential with respect to mass asymmetry is deduced from the widths of measured mass distributions [3].
- The excitation-energy-sorting mechanism [4,5,6,7] determines the prompt neutron yields and the odd-even effect in fission-fragment yields of even-Z and odd-Z systems.
- Neutron evaporation and gamma emission are calculated with a Monte-Carlo statistical code using level densities from empirical systematics and binding energies with theoretical shell effects. Gamma competition at energies above the neutron threshold is considered.
The official GEF websites are http://www.khs-erzhausen.de and http://www.cenbg.in2p3.fr/GEF.
GEF is a computer code for the simulation of the nuclear fission process. The GEF code calculates pre-neutron and post-neutron fission-fragment nuclide yields, angular-momentum distributions, isomeric yields, prompt-neutron yields and prompt-neutron spectra, prompt-gamma spectra and several other quantities for a wide range of fissioning nuclei from polonium to seaborgium in spontaneous fission and neutron-induced fission. The result refers to first-chance fission. Output is provided as tables and as values of fission observables on an event-by-event basis.
Specific features of the GEF code:
- The mass division and the charge polarisation are calculated assuming a statistical population of states in the fission valleys at freeze-out. The freeze-out time considers the influence of fission dynamics and is not the same for the different collective variables.
- The separability principle [1] governs the interplay of macroscopic and microscopic effects.
- Four fission channels are considered. The strengths of the shells in the fission valleys are identical for all fissioning systems. The mean positions of the heavy fragments in the asymmetric fission channels are essentially constant in atomic number, as suggested by experimental data [2].
- The stiffness of the macroscopic potential with respect to mass asymmetry is deduced from the widths of measured mass distributions [3].
- The excitation-energy-sorting mechanism [4,5,6,7] determines the prompt neutron yields and the odd-even effect in fission-fragment yields of even-Z and odd-Z systems.
- Neutron evaporation and gamma emission are calculated with a Monte-Carlo statistical code using level densities from empirical systematics and binding energies with theoretical shell effects. Gamma competition at energies above the neutron threshold is considered.
The official GEF websites are http://www.khs-erzhausen.de and http://www.cenbg.in2p3.fr/GEF.
NEA-1864/04
GEF-code, Version 2012/2.4 (June 2012) contains some modifications in the energy balance with respect to the previous version.[ top ]
[ top ]
[ top ]
[ top ]
8. RELATED AND AUXILIARY PROGRAMS
The main routines are written in FreeBASIC (http://www.freebasic.net/). FeeBASIC produces compiled binary code using the C run-time library. Graphics output is based on the X11 library. A graphical user interface is provided for Windows, written in JustBasic (http://www.justbasic.com/), which has a specific run-time library.
The main routines are written in FreeBASIC (http://www.freebasic.net/). FeeBASIC produces compiled binary code using the C run-time library. Graphics output is based on the X11 library. A graphical user interface is provided for Windows, written in JustBasic (http://www.justbasic.com/), which has a specific run-time library.
[ top ]
10. REFERENCES
[1] Experimental evidence for the separability of compound-nucleus and fragment properties in fission, K.-H. Schmidt, A. Kelic, M. V. Ricciardi, Europh. Lett. 83 (2008) 32001
[2] Nuclear-fission studies with relativistic secondary beams: analysis of fission channels, C. Boeckstiegel et al., Nucl. Phys. A 802 (2008) 12
[3] Shell effects in the symmetric-modal fission of pre-actinide nuclei, S. I. Mulgin, K.-H. Schmidt, A. Grewe, S. V. Zhdanov, Nucl. Phys. A 640 (1998) 375
[4] Entropy-driven excitation-energy sorting in superfluid fission dynamics,
K.-H. Schmidt, B. Jurado, Phys. Rev. Lett. 104 (2010) 212501
[5] New insight into superfluid nuclear dynamics from the even-odd effect in fission, K.-H. Schmidt, B. Jurado, arXiv:1007.0741v1 [nucl-th]
[6] Thermodynamics of nuclei in thermal contact, K.-H. Schmidt, B. Jurado, Phys. Rev. C 82 (2011) 014607
[7] Final excitation energy of fission fragments, K.-H. Schmidt, B. Jurado, Phys. Rev. C 83 (2011) 061601(R)
[8] Systematics of nuclear level density parameters, Till von Egidy, Dorel Bucurescu, Phys. Rev. C 72 (2005) 044311
[9] Nuclear ground state masses and deformations, P. Moeller et al., Atom. Data Nucl. Data Tables 59 (1995) 185
[1] Experimental evidence for the separability of compound-nucleus and fragment properties in fission, K.-H. Schmidt, A. Kelic, M. V. Ricciardi, Europh. Lett. 83 (2008) 32001
[2] Nuclear-fission studies with relativistic secondary beams: analysis of fission channels, C. Boeckstiegel et al., Nucl. Phys. A 802 (2008) 12
[3] Shell effects in the symmetric-modal fission of pre-actinide nuclei, S. I. Mulgin, K.-H. Schmidt, A. Grewe, S. V. Zhdanov, Nucl. Phys. A 640 (1998) 375
[4] Entropy-driven excitation-energy sorting in superfluid fission dynamics,
K.-H. Schmidt, B. Jurado, Phys. Rev. Lett. 104 (2010) 212501
[5] New insight into superfluid nuclear dynamics from the even-odd effect in fission, K.-H. Schmidt, B. Jurado, arXiv:1007.0741v1 [nucl-th]
[6] Thermodynamics of nuclei in thermal contact, K.-H. Schmidt, B. Jurado, Phys. Rev. C 82 (2011) 014607
[7] Final excitation energy of fission fragments, K.-H. Schmidt, B. Jurado, Phys. Rev. C 83 (2011) 061601(R)
[8] Systematics of nuclear level density parameters, Till von Egidy, Dorel Bucurescu, Phys. Rev. C 72 (2005) 044311
[9] Nuclear ground state masses and deformations, P. Moeller et al., Atom. Data Nucl. Data Tables 59 (1995) 185
NEA-1864/04, included references:
- K.-H. Schmidt and B. Jurado:General model description of fission observables
- Karl-Heinz Schmidt and Beatriz Jurado:
Prompt-neutron and prompt-gamma emission from a general description of the
fission process (JEF/DOC 1423)
[ top ]
11. HARDWARE REQUIREMENTS
GEF can be compiled and installed under Windows and linux, using exactly the same sources files. Specific executables are provided for the two systems. The authors tested GEF on Windows and linux.
Memory less than 50 MByte; Disc less than 100 MByte, eventually more for event-wise output.
GEF can be compiled and installed under Windows and linux, using exactly the same sources files. Specific executables are provided for the two systems. The authors tested GEF on Windows and linux.
Memory less than 50 MByte; Disc less than 100 MByte, eventually more for event-wise output.
[ top ]
[ top ]
[ top ]
[ top ]
NEA-1864/04
FreeBASIC source filesJustBasic executable and run-time-library
Executables for Windows and linux
ReadMe file with technical instructions
Keywords: Monte Carlo method, nuclear fission, statistical models.