Search results for "Nuclear isomer"
showing 10 items of 17 documents
Isomeric state of $^{80}$Y and its role in the astrophysical rp-process
2001
5 pages, 7 figures.-- PACS nrs: 21.10.Tg; 23.20.Nx; 27.50.+e.
Metastable electronic states induced by nuclear decay and light
1994
Radioactive atoms incorporated in insulating solid-state compounds create various kinds of chemical and physical “after-effects” upon nuclear disintegration. Mossbauer emission spectroscopy of57Co-labelled coordination compounds has undoubtedly become the most informative technique to detect such after-effects like aliovalent charge and spin states of the nucleogenic iron atom resulting from the57Co(EC)57Fe decay, low energy excitations of crystal field and Zeeman states, linkage isomerism, radical formation with subsequent redox reactions, and others. We have extensively studied57Co-labelled complexes with [CoIIN6] cores employing time-integral and time-resolved Mossbauer emission spectros…
Isomeric state of 80Y and its role in the rp-process
2003
The HIGISOL facility has been used to investigate carefully the isomeric transition 228.5 keV in 80Y. We have measured the electron internal conversion coefficient for this transition αK = 0.50 ± 0.07 which gives the value for half-life of “bare” isomeric state T 1/2 = 6.8 ± 0.5 s. The isomeric state should play an important role in the rp-process calculations.
Atomic spectroscopy studies of short-lived isotopes and nuclear isomer separation with the ISOLDE RILIS
2002
The Resonance Ionization Laser Ion Source (RILIS) at the ISOLDE on-line isotope separator is based on the selective excitation of atomic transitions by tunable laser radiation. Ion beams of isotopes of 20 elements have been produced using the RILIS setup. Together with the mass separator and a particle detection system it represents a tool for high-sensitive laser spectroscopy of short-lived isotopes. By applying narrow-bandwidth lasers for the RILIS one can study isotope shifts (IS) and hyperfine structure (HFS) of atomic optical transitions. Such measurements are capable of providing data on nuclear charge radii, spins and magnetic moments of exotic nuclides far from stability. Although t…
Note on the decay of200Au
1972
Gamma and beta rays from the decay of200Au (48.4 min) were studied employing Ge(Li) and plastic detectors in various singles and coincidence arrangements. The intensity of the β-branch to the ground state of200Hg was determined as 79%, and the disintegration energy of200Au to be asQβ=2.26 ± 0.06 MeV. A tentative spin and parity assignment of (1,2)+ is proposed for levels at 1515.2 and 1972.5 keV in 200Hg
A new isomer in 125La
1999
Levels in 125La have been studied via β+/EC decay of on-line mass-separated 125Ce using the HIGISOL technique. A new (390 ± 40) ms isomer is definitely attributed to 125La by conversion electron measurements of the 107 keV E3 isomeric transition.
Decay of24Al and24Almto γ-Ray and α-Particle Emitting States in24Mg
1979
The level structure of 24Mg and decay properties of 129 ms 24Alm and 2.07 s 24Al have been investigated by means of γ-ray and particle spectroscopy. The energy and intensity of the isomeric transition were measured to be 425.8 ± 0.1 keV and (82.5 ± 3.0)%, respectively. The isomer was observed to decay via a super-allowed transition with a log ft value of 3.51 ± 0.04 to its 1+, 9965.2 ± 1.5 keV analog state in 24Mg. In addition, decay to seven particle-emitting levels and four levels depopulated by γ-ray emission were observed. In the decay of 2.07 s 24Al a new delayed α-particle group with an energy 3.04 MeV and three new γ-transitions were observed. More accurate values than those reported…
Prompt and delayed spectroscopy ofAt199
2010
The neutron-deficient nucleus $^{199}\mathrm{At}$ has been studied through $\ensuremath{\gamma}$-ray and electron spectroscopy, using the recoil-decay tagging technique. Two experiments were conducted, using a gas-filled recoil separator with a focal-plane spectrometer alone and together with a germanium-detector array at the target position. The resulting level scheme for $^{199}\mathrm{At}$ includes a new isomer with a half-life of 0.80(5) $\ensuremath{\mu}$s and a spin and parity of ($29/{2}^{+}$). The $13/{2}^{+}$ isomer, which de-excites via an $M2$ transition to the $9/{2}^{\ensuremath{-}}$ ground state, was measured to have a half-life of 70(20) ns. Our earlier version of the level s…
Is the single-state dominance realized in double-β-decay transitions?
1998
In the single-state-dominance hypothesis (SSDH) the decay rate of the two-neutrino double-\ensuremath{\beta} decay to the final ground state is solely determined by virtual single-\ensuremath{\beta}-decay transitions via the ${1}^{+}$ ground state of the intermediate nucleus. A very important consequence the SSDH will be that some of nonaccelerator measurements of double-\ensuremath{\beta}-decay observables could be circumvented by single-\ensuremath{\beta}-decay measurements. To assess the validity of the SSDH, we have carried out a theoretical analysis of all double-\ensuremath{\beta}-decay transitions where the spin-parity of the ground-state of the intermediate nucleus is ${1}^{+}$. The…
Low-lying levels of201Hg from the decay of201Au
1972
The decay of 26.4-min201Au has been investigated using chemically separated sources and Ge(Li), Si(Li), plastic and Nal(Tl) detectors in different singles and coincidence arrangements. The β-disintegration energy was measured to be 1.27 ± 0.10 MeV. Thirteen γ-rays were observed to belong to this decay and the new levels at 543, 549.2, 552.8, 559.1, 605.7, 645.4, 732 and 1188 keV were established in201Hg, in addition to the three previously known excited states below 200 keV.