232 Th fission fragment angular distribution (FFAD)

FUSTIPEN - Caen – 13/10/2014 L. Tassan-Got

Fission fragment angular distribution and isotopic distributions

Fission fragment angular distributionsand isotopic distributions

L. Tassan-Got and n_TOF and SOFIA



232Th fission fragment angular distribution (FFAD)

• Detection of the 2 fission fragments• Fission direction given by the positions of the 2 fragments

• 9 Targets and 10 detectors tilted by 45°• 1x235U 1x238U 1x237Np 6x232Th



Examples of angular distributions





Rules of thumb for FFADs

220

TJK eff





Fissility effect

Lower fissility higher barrier lower temperature lower K0

lower K’s higher positive anisotropy



Anisotropy for p+X at 40 MeV





Systematics of linear momentum transfer

At 40 MeV almost full momentum transfer: in most of the cases the proton is captured by the target nucleus



SOFIA experiment

From courtesy of J. Taieb, T. Corbinet, J. Fiona-Martin, E. Pellereau, A. Chatillon



238U Z1+Z2=92 selection



Mass resolution



Fission of 238U: mass yield



• Even-odd effect=10% (<E*>~14 MeV) vs Lohengrin=24% (<E*>=6 MeV)• Even-odd effect decreases with excitation energy

Fission of 238U: charge yield



Fission of 238U: isotopic yields for heavy fragment



Fission of neutron deficient nuclei

x K.H. Schmidt et al., Nucl. Phys. A665 (2000) 221














Energetics of Sn isotopesfor fission of 235U <𝜈>=Nf - N1 - <N2>

Courtesy of Julie Fiona-Martin



• Even-odd effect=5% (<E*>~14 MeV) vs Lohengrin=5% (<E*>=6 MeV)• Evaporation ?

Fission of 238U: isotonic yield

Documents

232 Th fission fragment angular distribution (FFAD)