P. Jesinger

Angular correlations in ternary fission induced by polarized neutrons

Ternary fission induced by cold polarized neutrons was studied for the two isotopes 233U and 235U at the Institut Laue-Langevin in Grenoble, France. In particular two types of angular correlations between the spin of the incoming neutrons and the emission directions of both, the fission fragments (FF) and the ternary particles (TP), were investigated. For FF and TP detectors facing the target at right angles to the neutron beam, first, for longitudinally polarized neutrons a triple correlation between spin and the emission of outgoing particles was explored and, second, for transversally polarized neutrons parity violating asymmetries in the emission of FFs and TPs were analyzed. Nonzero expectation values for the triple correlation were oberserved in the present experiments for the first time.

Spontaneous ternary fission of 252Cf: New experiment with GSI super clover detectors

A new multiparameter experiment on ternary fission of 252Cf has recently been successfully performed by using the CODIS2 detector system and two GSI segmented Super Clover Ge γ-ray detectors. The experimental setup and the main subjects of interest are briefly described.

Left-right asymmetry of the angular distribution of long-range alpha particles from ternary 235U fission induced by cold polarized neutrons

Left–Right Asymmetry of the Angular Distribution of Long-Range Alpha Particles from Ternary 235U Fission Induced by Cold Polarized Neutrons* G. V. Danilyan1), A. M. Fedorov1), A. M. Gagarski2), F. Goennenwein3), P. Jesinger3), J. von Kalben4), A. Koetzle3), Ye. I. Korobkina5), I. T. Krasnoshchekova2), M. Mutterer4), V. V. Nesvizhevsky6), S. R. Neumaier4), Yu. B. Novozhilov1), V. S. Pavlov1), G. A. Petrov2),

Studies On Particle‐Accompanied Fission Of 252Cf(sf) And 235U(nth,f)

In recent multi‐parameter studies of spontaneous and thermal neutron induced fission, 252Cf(sf) and 235U(nth,f) respectively, the energies and emission angles of fission fragments and light charged particles were measured. Fragments were detected by an energy and angle sensitive twin ionization chamber while the light charged particles were identified by a series of ΔE‐Erest telescopes. Up to Be the light particle isotopes could be disentangled. In addition, in the 252Cf(sf) experiment, gammas emitted by the fragments were analyzed by a pair of large‐volume segmented clover Ge detectors. Here the main interest is to study the γ‐decay and the anisotropy of gammas emitted by fragments and light particles. On the other hand, the high count rates achieved in the U‐experiment performed at the high flux reactor of the ILL, Grenoble, should allow to explore fragment‐particle correlations in very rare events like quaternary fission. At the present stage of data evaluation, yields and energy distributions of light...

Can Time Reversal be tested in ternary fission

Ternary fission of 233U and 235U induced by cold polarized neutrons has been investigated. Several correlations between neutron spin and the momenta of fission fragments and ternary particles were analyzed. These correlations are probing time reversal invariance, parity non-conservation and left-right asymmetries. Results for all three correlations from the reaction 233U(n,f) are presented. Especially the outcome in the searches for time reversal correlations and left-right asymmetries is unexpected. A huge effect observed formally as a violation of time reversal is most probably simulated by specific properties of the emission mechanism for ternary particles.