Contribution to the design, fulfillment, and data analysis of fission fragment yields of the SOFIA experiment at GSI
Jeudi 23 janvier 2014 11:00
- Duree : 1 heure
Lieu : Seminar room ILL1, 6 rue Jules Horowitz - Grenoble
Orateur : E. PELLEREAU (CEA DAM/DIF)
The isotopic fission yields of 238U following the SOFIA experiment, conducted at the GSI facility (Darmstadt), will be presented. This experiment takes advantage of the inverse kinematics technique at relativistic energies. Benefits are several : fission fragments are highly focused (high geometrical efficiency) and are also completely stripped, which greatly simplifies their nuclear charge measurement. The first detector of the SOFIA setup is an active target in which fission occurs via electromagnetic excitation, followed by an ionization chamber to measure the nuclear charge and the horizontal angle of both fission fragments. The masses are deduced by the bending radius measurement of the fragments, deflected by a strong magnet (ALADIN), thanks to two position detectors (MWPC), and also by a highly resolved time-of-flight measurement (40 ps FWHM) so that heavy neighbouring isotopes can be separated. The data analysis shows that the main goals are achieved since the isotopic separation is reached over the whole range of the fission fragments. A strong even-odd effect is seen in the charge spectrum but, surprisingly, the neutron even-odd effect of the light region is seen to be very close to the one in thermal neutron induced fission. The peak-to-valley ratio of the mass spectrum confirms that the mean excitation energy at fission is close to the expected one (14 MeV).
Contact : blanc@ill.fr
Discipline évènement : (Physique)
Entité organisatrice : (ILL)
Nature évènement : (Séminaire)
Evènement répétitif : (General ILL Seminar - College 3)
Site de l'évènement : Polygone scientifique
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