0000000000751933
AUTHOR
E. Bouchez
New shape isomer in the self-conjugate nucleus $^{72}$Kr
A new isomeric ${0}^{+}$ state was identified as the first excited state in the self-conjugate ($N=Z$) nucleus $^{\mathrm{72}}\mathrm{K}\mathrm{r}$. By combining for the first time conversion-electron and gamma-ray spectroscopy with the production of metastable states in high-energy fragmentation, the electric-monopole decay of the new isomer to the ground state was established. The new ${0}^{+}$ state is understood as the band head of the known prolate rotational structure, which strongly supports the interpretation that $^{\mathrm{72}}\mathrm{K}\mathrm{r}$ is one of the rare nuclei having an oblate-deformed ground state. This observation gives in fact the first evidence for a shape isomer…
FRIPON: a worldwide network to track incoming meteoroids
Context. Until recently, camera networks designed for monitoring fireballs worldwide were not fully automated, implying that in case of a meteorite fall, the recovery campaign was rarely immediate. This was an important limiting factor as the most fragile - hence precious - meteorites must be recovered rapidly to avoid their alteration. Aims. The Fireball Recovery and InterPlanetary Observation Network (FRIPON) scientific project was designed to overcome this limitation. This network comprises a fully automated camera and radio network deployed over a significant fraction of western Europe and a small fraction of Canada. As of today, it consists of 150 cameras and 25 European radio receiver…
Spectroscopy of very neutron-deficient 187,189Bi isotopes
Shape coexistence is well known to occur in nuclei, in particular near closed shells [1], where particle-hole excitations across the shell gap can create deformed intruder states. In the neutron-deficient lead isotopes (Z = 82), deformed structures appear at low excitation energy. The isotope 188Pb [2] shows for example a triple shape coexistence with oblate and prolate excited 0+ states that compete with the spherical ground state. The study of the odd-proton single-particle excitations in Bi isotopes allows to obtain information on the orbitals involved in the different shapes observed in this mass region.
Isomeric states in proton-unbound 187, 189Bi isotopes
Prompt and delayed gamma-ray spectroscopy of very neutron-deficient bismuth isotopes 187, 189Bi has been performed using the Recoil Decay Tagging (RTD) method. The isomeric i 13/2 states have been identified and their lifetimes have been measured. The systematics of these long-lived M2 isomers has been extended to the proton-unbound isotopes. The general behaviour of single-proton states is discussed within the systematics and interpreted within the shell-model framework.