Department of Physics and Astronomy

Fission yield measurements

We study properties of fragments produced in fission of heavy nuclei like 234,238U and 232Th - properties such as mass yields and energy- and angular distributions, as a function of excitation energy.

These explorations are relevant for both basic nuclear physics and for nuclear applications. Despite the vast amount of measurements historically devoted to nuclear fission we still lack the full insight into the complex physics at the moment of scission. The interplay of the fundamental forces is a challenge to the existing models.

Many questions are yet to be answered, for example:

  • What drives the fissioning nucleus to select between symmetric and asymmetric mass split?
  • Why do we see a strong angular preference (i.e. anisotropy phenomenon) in the fission fragments emission?
  • How do resonance in the cross section influence the mass, energy and angular distributions?
  • What are the characteristics of the fission barrier?
  • What determines the neutron and gamma multiplicities and how are those values dependent on the mass and energy of the fission fragment?

The group has also interest in the development of detectors and data acquisition systems.

Selected publications

Al-Adili, A., Hambsch, F., Pomp, S., Oberstedt, S. (2012).
Indication of anisotropic TKE and mass emission in 234U(n,f)
In Stephan Oberstedt (red.) Physics Procedia, 158-164 doi: 10.1016/j.phpro.2012.04.021

Al-Adili, A., Hambsch, F., Stephan, P., Stephan, O. (2012).
Impact of prompt-neutron corrections on final fission-fragment distributions
Physical Review C. Nuclear Physics, 86(5): 054601- doi: 10.1103/PhysRevC.86.054601

Al-Adili, A., Hambsch, F., Bencardino, R., Oberstedt, S., Pomp, S. (2012).
Ambiguities in the grid-inefficiency correction for Frisch-Grid Ionization Chambers
Nuclear Instruments and Methods in Physics Research Section A, Elsevier. 673: 116-121 doi: 10.1016/j.nima.2011.01.088

Al-Adili, A., Hambsch, F., Bencardino, R., Pomp, S., Oberstedt, S. et al. (2012).
On the Frisch–Grid signal in ionization chambers.
Nuclear Instruments and Methods in Physics Research Section A, Elsevier. 671: 103-107 doi: 10.1016/j.nima.2011.12.047

I. V. Ryzhov, G. A. Tutin, V. D, Simutkin et al. (2011).
Measurement of Fragment Mass Yields in Neutron-induced Fission of (232)Th and (238)U at 33, 45 and 60 MeV.
Journal of the Korean Physical Society, 59(2), 1864-1867.
doi: 10.3938/jkps.59.1864

Al-Adili, A., Hambsch, F., Oberstedt, S., Pomp, S., Zeynalov, S. (2010).
Comparison of digital and analogue data acquisition systems for nuclear spectroscopy
Nuclear Instruments and Methods in Physics Research Section A, 624(3): 684-690 doi: 10.1016/j.nima.2010.09.126

V. D. Simutkin (2008)
Measurement of Fragment Mass Distributions in Neutron-Induced Fission of 238U och 232The at Intermediate Energies
Proceedings of International Nuclear Youth Congress