Search results for "Decay"
showing 10 items of 2087 documents
Structure ofSb118nucleus
1992
{gamma}, {gamma}{gamma}-coincidence, internal conversion electron, and {gamma}-ray angular distribution spectra of the {sup 118}Sn({ital p},{ital n}{gamma}){sup 118}Sb reaction were measured at different bombarding proton energies between 5.5 and 7.5 MeV. {gamma}, {gamma}{gamma}-coincidence, and internal conversion electron spectra of the {sup 115}In ({alpha},{ital n}{gamma}){sup 118}Sb reaction were also measured at {ital E}{sub {alpha}}=14.5 MeV. Ge(HP), Ge(Li), Ge(LEPS) {gamma}-ray detectors, as well as a superconducting magnetic lens electron spectrometer (with Si(Li) detectors), were used in the experiments. About 210 (including {similar to}130 new) {gamma} rays have been assigned to {…
(e,e'f) Coincidence experiments on 235U and 238U
1990
Abstract Coincidence experiments for (e, e'f) on the actinide nuclei 235 U and 238 U have been performed at the Mainz Microtron (MAMI A) concentrating on three subjects: multipole strength distributions and form factors for the lowest multipolarities, the mass split in the fission decay of various giant multipole resonances, and the separation of near barrier fission channels. Data were taken at four values of momentum transfer ( q eff ≈ 0.20, 0.28, 0.53, and 0.71 fm −1 for 238 U, q eff ≈ 0.20, 0.44, 0.57, and 0.71 fm −1 for 235 U) for excitation energies ω = 4–22 MeV. The fission fragments have been detected using the Giessen PPAC-Ball. A model-independent multipole analysis yields both fo…
Manifestations of Clustering in Fission of Excited Actinides
2003
A new, graphical way of extracting important physical information from the total kinetic-energy—mass (TKE—M) distributions of the nuclear reaction products is presented. The resulting images indicate for the first time the presence of the Ni—Mo and Ge—Mo fission modes in the fission of Np nuclei at intermediate excitation energies.
Total Absorption Study of Beta Decays Relevant for Nuclear Applications and Nuclear Structure
2014
Abstract An overview is given of our activities related to the study of the beta decay of neutron rich nuclei relevant for nuclear applications. Recent results of the study of the beta decay of 87,88 Br using a new segmented total absorption spectrometer are presented. The measurements were performed at the IGISOL facility using trap-assisted total absorption spectroscopy.
New nuclideHa263
1992
A new nuclide $^{263}\mathrm{Ha}$ was produced in the bombardment of a $^{249}\mathrm{Bk}$ target with 93-MeV $^{18}\mathrm{O}$ ions. It was detected via spontaneous fission counting and was shown to have a half-life of about 0.5 min. This activity was also separated from the reaction products by automated rapid chemical separations using cation-exchange chromatography in 0.05M \ensuremath{\alpha}-hydroxyisobutyric acid. After chemical separation, $^{263}\mathrm{Ha}$ was found to decay by spontaneous fission (${57}_{\mathrm{\ensuremath{-}}15}^{+13}$%) and by \ensuremath{\alpha} emission (${\mathit{E}}_{\mathrm{\ensuremath{\alpha}}}$=8.35 MeV, 43%) with a half-life of ${27}_{\mathrm{\ensurem…
The new neutron-rich nuclei231Fr and231Ra
1985
The new neutron-rich isotope231Fr has been produced in a spallation reaction of238U induced by 600 MeV protons and identified by mass-separation and decay spectroscopy. In addition, the so far unknown231Ra and the known231Ac have been observed as daughter products. The Z-assignments were performed via the decay of KX-rays, and genetic relationships. Half-lives of 17.5(8) s and 103(3) s were obtained for231Fr and231Ra, respectively.
αdecay of the new isotope206Ac
1998
The new neutron-deficient nuclide {sup 206}Ac was produced by bombarding a {sup 175}Lu target with 5.5 MeV/nucleon {sup 36}Ar ions. The evaporation residues were separated in flight by a gas-filled separator and subsequently identified by the {alpha}-{alpha} position and time correlation method. {sup 206}Ac was found to have two {alpha} particle emitting isomeric levels with half-lives of (22{sub {minus}5}{sup +9}) ms and (33{sub {minus}9}{sup +22}) ms, and with {alpha} particle energies of (7790{plus_minus}30) keV and (7750{plus_minus}20) keV, respectively. The former isomer is tentatively assigned to a J{sup {pi}}=3{sup +} level and the latter to a J{sup {pi}}=10{sup {minus}} level, both …
α-Decay branching ratios measured by γ-ray tagging
2008
Abstract The nuclides 168–170Pt were produced by bombarding isotopically enriched 92,94Mo targets with 336, 348 MeV 78Kr ions. Prompt γ rays were detected at the target position and provided a selection criterion for the 168–170Pt nuclei. This technique enables the problem of the background from higher-energy α decays in the spectrum to be circumvented. The Pt nuclei were separated in flight using the gas-filled separator RITU and implanted into the GREAT spectrometer, which was used to study subsequent α decays. The α -decay branching ratios of 164–166Os were deduced from the fraction of selected 168–170Pt nuclei correlated with α decays of 164–166Os. The resulting branching ratios agree w…
Beta decay half-lives of neutron rich Ti–Co isotopes around
1999
Abstract The neutron-rich 57 – 59 Ti, 59 – 62 V, 61 – 64 Cr, 63 – 66 Mn, 65 – 68 Fe, 67 – 70 Co have been produced at GANIL via interactions of a 60.4 MeV/u 86 Kr 34+ with a 58 Ni target. They have been separated by the doubly achromatic spectrometer LISE3. Beta-decay half-lives have been determined for all produced nuclei, and subsequent γ -rays have been observed for the most efficiently produced nuclei. The measured half-lives of vanadium and chromium isotopes are compared to QRPA calculations using ground states deformations from the FRDM or ETFSI models. In an astrophysical context, the short half-lives of 58 Ti and 64 Cr indicate that these nuclei are potential r-process progenitors, …
High-Kfour-quasiparticle states inGd138
2011
States above the known ${K}^{\ensuremath{\pi}}={8}^{\ensuremath{-}}$ 6 $\ensuremath{\mu}$s isomer in $^{138}\mathrm{Gd}$ have been populated with the $^{106}\mathrm{Cd}$($^{36}\mathrm{Ar}$,$2p2n$) reaction at a beam energy of 180 MeV at the University of Jyv\"askyl\"a, Finland. The recoil-isomer tagging technique was utilized to correlate delayed $\ensuremath{\gamma}$-ray decays, detected in the GREAT focal plane spectrometer, with prompt decays measured in the JUROGAM II spectrometer at the target position. The lifetime of the ${K}^{\ensuremath{\pi}}={8}^{\ensuremath{-}}$ isomeric state has been remeasured as 6.2(2) $\ensuremath{\mu}$s. Two high-lying strongly coupled bands have been estab…