共查询到20条相似文献,搜索用时 31 毫秒
1.
K. Sümmerer N. Kaffrell H. Otto P. Peuser N. Trautmann 《Zeitschrift für Physik A Hadrons and Nuclei》1978,287(3-4):287-297
Theβ ? — andγ-activities of 18.4 min104Tc have been studied with singles and coincidence measurements. Sources were prepared by chemical separation of technetium from the fission products of thermal-neutron-induced fission of235U. A revised level scheme of104Ru up to an excitation energy of 4.26 MeV is proposed. Fromβ-γ coincidence measurements, aQ β-value of 5.62±0.07 MeV has been obtained. 相似文献
2.
K. Shizuma H. Ahrens J. P. Bocquet N. Kaffrell B. D. Kern H. Lawin R. A. Meyer K. Sistemich G. Tittel N. Trautmann 《Zeitschrift für Physik A Hadrons and Nuclei》1984,315(1):65-75
Theβ ? decays of103Nb and105Nb have been studied at the fission product separators JOSEF and LOHENGRIN. Half-lives of (1.5±0.2) s and (2.95±0.06) s, respectively, have been determined for these decays. Fromγ singles andγ-γ coincidence measurements extended level schemes for103Mo and105Mo have been established for the first time. The lowest energy levels of these nuclei are consistent with the interpretation as members of rotational bands built on a 3/2+ [411] Nilsson state. Evidence is presented for the location of the 9/2+ [404] configuration. 相似文献
3.
H. A. Selič G. Sadler T. A. Khan W. -D. Lauppe H. Lawin K. Sistemich E. Monnand J. Blachot J. P. Bocquet F. Schussler 《Zeitschrift für Physik A Hadrons and Nuclei》1979,289(2):197-210
Theβ-decays of99Y and99Zr have been investigated with the two recoil fission product separators JOSEF and LOHENGRIN. Half-lives of 1.51±0.08s and 2.1±0.1s respectively, have been determined. Aβ-decaying isomeric state has been observed in99Y. The level schemes of 40 99 Zr59 and 41 99 Nb58 have been established fromγ-ray spectroscopy. Absoluteγ-intensities have been obtained by means of two independent techniques. Halflives of 293±10 ns for the 251.9 keV state and 10.2±1.5 ns for the 614.0 or 667.2 keV level in99Zr have been measured through delayedβ,γ- andγ,γ-coincidence experiments. Values for the spins and parities of the low lying levels in99Zr are proposed in accordance with the systematics of lighter odd Zr isotopes. Spins and partities are assigned to some levels in99Nb fromγ,γ-angular correlation measurements. In this nucleus there is evidence for three-particle configurations of some excited states, where the odd proton is coupled to two neutrons which are in different orbits. 相似文献
4.
J. Stachel N. Kaffrell N. Trautmann K. Brodén G. Skarnemark D. Eriksen 《Zeitschrift für Physik A Hadrons and Nuclei》1984,316(1):105-119
Levels in106,108Ru have been studied by measuringγγ coincidences andγγ directional correlations of theγ-rays following theβ ?-decay of 36 s106Tc and 5 s108Tc. Tc activities were separated chemically from the fission products of thermal neutron induced fission of239Pu by the continuously running system “SISAK 2” and theγ-radiation was measured on-line. An extended level scheme for108Ru, spin assignments,E2/M1 multipole mixing ratios andB(E2) ratios for106Ru and108Ru have been obtained. The collective structure of the two nuclei is discussed in the framework of different nuclear models. 相似文献
5.
By means of X-γ andγ-γ coincidence measurements of the35Cl+58Ni reaction products, 38γ lines have been identified to be in coincidence with KX(Tc)-rays and assigned to the decay of90Ru. Its half-life of 11±3 s has been deduced from the 154.6 keVγ-decay. The result supports our previous identification of90Ru produced in the same reactions. 相似文献
6.
P. J. Tivin R. L. Schulte H. W. Taylor 《Zeitschrift für Physik A Hadrons and Nuclei》1975,273(4):339-347
104Tc was produced through the104Ru(n, p)104Tc reaction using target material enriched to 99.7% in104Ru. The energies and intensities of theγ-rays emitted by104Tc were measured with a multichannel Ge(Li) spectrometer. A revised level scheme is proposed which contains 33 levels and incorporates 85γ- ray transitions. The half life of104Tc was observed to be 18.2±0.5 min. 相似文献
7.
By delayed coincidence techniques, the half-life of the 344 keV level in105Pd, populated by the decay of105Ag, was measured:T 1/2=(1.01±0.05) · 10?9s. A comparison of this value with the prediction of the single-particle model shows good agreement for the 344 keVE2 transition. 相似文献
8.
The level scheme of91Tc has been studied by means of in-beamγ-ray spectroscopy in the irradiations of58Ni and54Fe targets by40Ca beams from the Munich MP tandem and the heavy ion post accelerator. A large number of positive as well as of negative parity yrast-levels with excitation energies up to 8 MeV has been established. The level scheme of91Tc has been compared with shell model claculations and a good agreement for all identified levels has been found. In parallel investigations of the residual activities of the reaction40Ca→54Fe, theβ decay of the (9/2+ ground) state of91Ru has been investigated. Aβ decay scheme of91Ru(9/2+) has been established. The half-life of91Ru(9/2+) has been measured to be 9±1 s. 相似文献
9.
H. H. Güven B. Kardon H. Seyfarth 《Zeitschrift für Physik A Hadrons and Nuclei》1978,287(3-4):271-285
Theγ radiation following thermal neutron capture in104Ru has been investigated through singles, coincidence, and angular correlation measurements in order to solve existing discrepancies and to complete the knowledge about the transitional odd-N nucleus 44 105 Ru61. The resulting level andγ-decay scheme is found to be very similar to that of the odd-Z transitional nucleus 61 149 Pm88. Between the 11/2?, 15/2?, and 19/2? states which are interpreted as members of the decoupled band, built on the unique parity 11/2? single particle state, low spin states of negative parity are found at surprisingly low excitation energies above the 11/2? state. In the frame of the particleplus-rotor model their positions would require a sharp decrease of the rotational parameter with increasing collective angular momentum of the soft core. 相似文献
10.
T. A. Khan W. D. Lauppe H. A. Selič H. Lawin G. Sadler M. Shaanan K. Sistemich 《Zeitschrift für Physik A Hadrons and Nuclei》1975,275(3):289-296
A windowless Si(Li) electron detector has been used in conjunction with the gas filled fission product separator JOSEF to study totally converted transitions in Zr and Mo isotopes. The existence of twoβ-decay modes in96Y,98Y and100Nb is confirmed. The half-lives of theβ-decaying levels feeding O 2 + states in96Zr and98Zr are 6.0 ± 0.4 sec and 0.60±0.05 sec respectively. A search for other first excited O 2 + states shows that no such states are apparent in100Zr and104Mo. 相似文献
11.
A. Jokinen J. Äystö P. Dendooven K. Eskola Z. Janas P. P. Jauho M. E. Leino J. M. Parmonen H. Penttilä K. Rykaczewski P. Taskinen 《Zeitschrift für Physik A Hadrons and Nuclei》1991,340(1):21-28
Neutron-rich nuclides110Ru and112Ru produced in symmetric fission of238U by 20 MeV protons have been studied at the IGISOL facility by means ofβ-ray,γ-ray and conversion electron spectroscopy. A total of 12 and 6γ-transitions were observed in the decays of110Ru and112Ru, respectively. Multipolarities were determined for a few transitions. The beta decay half-life was determined to be 11.6±0.6 s for110Ru and 1.75±0.07 s for112Ru. As a side product, a new value of 2.1±0.3 s for theβ half-life of the112Rh 1+ state was obtained. The decay energy measured with the plastic scintillator was 2.81 ±0.05 MeV for110Ru and 4.52 ±0.08 MeV for112Ru. The beta decay schemes of110Ru and112Ru isotopes indicate that the main fraction of their beta strength resides in two 0+→1+ spin-flip transitions with their logf t values between 4.4 and 4.7. The decay energies and the energies of the 1+ GT states are compared with the macroscopic-microscopic model calculations. The observed GT-strengths are discussed in the framework of the deformed single-particle model. 相似文献
12.
K. Sümmerer N. Kaffrell E. Stender N. Trautmann K. Brodén G. Skarnemark T. Björnstad I. Haldorsen J.A. Maruhn 《Nuclear Physics A》1980,339(1):74-88
The decay schemes of 36 s 106Tc and 5 s 108Tc have been studied with γ-ray singles and γ-γ coincidence measurements. To separate the technetium nuclides from the fission products of 239Pu, an on-line chemical separation procedure has been developed which is based on multistep chemical separations of liquid phases by fast-rotating centrifuges (“SISAK”). The resulting level schemes of 106Ru and 108Ru, together with those of 102Ru and 104Ru, are interpreted in terms of the generalized collective model of Gneuss and Greiner. The potential-energy surfaces calculated from the spectroscopic data show a trend towards triaxial shapes for the very neutron-rich Ru nuclei. 相似文献
13.
A. Odahara Y. Gono S. Mitarai T. Shizuma E. Ideguchi J. Mukai H. Tomura B. J. Min S. Suematsu T. Kuroyanagi K. Heiguchi T. Komatsubara K. Furuno 《Zeitschrift für Physik A Hadrons and Nuclei》1996,354(1):231-232
Decay scheme, half life andQ EC value of88Tc were deduced from aβ-decay study. The neutron deficient nucleus88Tc was produced by the58Ni(32S,pn)88Tc reaction using beam energies of 100, 101 and 105 MeV. The ground- and isomeric states of88Tc were found to decay to88Mo with similar half lives of 5.8±0.2 and 6.4±0.8 sec. The most probable spins and parities of these states are 3+ and 6+, respectively, though the order in energy could not be determined. TheQ EC value was deduced to be 8.6±1.3 MeV. 相似文献
14.
T. A. Khan W. D. Lauppe K. Sistemich H. Lawin G. Sadler H. A. Selic 《Zeitschrift für Physik A Hadrons and Nuclei》1977,283(1):105-120
Theβ-decay of100Y has been investigated at the gas filled recoil separator JOSEF by means ofγ-ray and conversion electron spectroscopy. Twoβ-decay modes, of half lives 0.94±0.03 s and 0.55±0.15 s, have been observed. Using Xγ-, Xce-, γγ- andγce-coincidences the level scheme of100Zr has been constructed. An excited 0 2 + state at 331.3 keV has been discovered in this nucleus. Theβ-decay from the 0.55 s decay mode in100Y shows a strong preference for the ground state compared to the 0 2 + state in100Zr. The structure of100Zr and the nature of the 0 2 + level is discussed in the light of the present results. 相似文献
15.
The residual activities of the projectile-target system40Ca→58Ni have been investigated with gamma and proton multi spectrum analyses,γγ andpγ coincidences. Aβ decaying high-spin isomer in95Pd withJ π=(21/2+), a half-life of 14±1 s and an excitation energy of about 2 MeV has been identified. It has been found that95Pd m is aβ delayed proton precursor. The totalβ branching to proton emitting states has been determined to be (0.74±0.19)·10?2. It has been observed that the final state in94Ru, populated after proton emission, is dominantly the 8+ state. A decay scheme of95Pd m has been derived. 相似文献
16.
W. Herzog N. Trautmann R. Denig G. Herrmann 《Zeitschrift für Physik A Hadrons and Nuclei》1976,276(4):393-402
TheΒ- andγ-radiations of98Zr and98m, g Nb have been investigated employing scintillation and semiconductor spectrometers and coincidence techniques. Sources of98Nb were produced by the98Mo(n, p)98Nb reaction, sources of98Zr by fission of235U with thermal neutrons applying chemical separations. For98Zr, a half-life of 30.7±0.4 sec and aQ β-value of 2.3±0.2 MeV were obtained, for the98Nb isomers, half-lives of 2.86±0.06 sec and 51.3±0.4 min, andQ β-values of 4.8±0.2 MeV and 4.5±0.2 MeV, respectively. Noγ-rays were observed in the decay of98Zr. The decay of 2.9 sec98Nb was found to involve 11γ-ray transitions. In the decay of 51 min98Nb, 54γ-transitions were detected. Spin and parity of 1+ and 4? were deduced for the isomeric states of98Nb. 相似文献
17.
The level scheme of97Tc has been investigated by observing theγ-rays following the decay of 2.9-d97Ru.γ-singles andγγ-coincidence measurements were carried out with Ge(Li)-detectors. The time difference of coincident γ-rays was measured as a third parameter. From the coincidence events, the intensities ofγγ-cascades were extracted. The97Ru decay gives rise to 18γ-lines which could be fitted into a level scheme of97Tc consisting of 9 levels. Spin and parity assignments of the levels were made from log(ft) values andγ-ray branching ratios. Discrepancies concerning the energy of the first 3/2? state and the existence of a 946 keV level are discussed. 相似文献
18.
M. Graefenstedt P. Jürgens U. Keyser F. Münnich F. Schreiber K. Balog T. Winkelmann H. R. Faust B. Pfeiffer 《Zeitschrift für Physik A Hadrons and Nuclei》1990,336(3):247-252
Theβ-decay energy of the neutron-rich isotopes148Ba,148La and151Pr has been measured at the Institute Laue-Langevin (ILL). The148Ba- and148La-nuclei were produced using a high-temperature ion source at the OSTIS separator of this institute, whereas samples of151Pr were obtained from the thermal fission of239Pu, used as a target in the mass separator LOHENGRIN. At both instruments,βγ-coincidences were measured with a plastic scintillator telescope and a Ge(I)-detector, together withβ-singles andγ-singles spectra. Theβ-spectra emitted in coincidence with 44γ-lines in the decay of these nuclei have been evaluated. From their endpoint energies, the followingQ β -values have been obtained:Q β (148Ba)=5115±60keV;Q β (148La)=7255±55 keV;Q β (151Pr)=4170±75 keV. Using these results, the nuclear massesA of these nuclei can be calculated with a relative error ΔA/A?5·10?7. In addition, the two-neutron separation energies and the mass excesses have been derived; the results are compared with recent predictions of theoretical mass calculations. 相似文献
19.
R. Katajanheimo T. Tuurnala E. Hammarén 《Zeitschrift für Physik A Hadrons and Nuclei》1978,286(1):57-63
TheΒ ?-decay of the longer-lived170Ho isomer produced through the170Er(n, p)170Ho reaction has been investigated by using a versastile detector and coincidence equipment. The half-life andΒ ?-decay energy were determined to beT 1/2=2.76±0.05 min andQ β =3.85±0.15 MeV, respectively. In addition to the ground state band and some higher energy levels, the proposed level scheme of170Er contains 11 states between 1.0 and 1.6 MeV (6 new ones), which are connected mutually by previously unknown low-energy transitions. Spin and/or parity assignments based mainly on coincidence data and multipolarity determinations are suggested for most of these states. By using systematic considerations and the nuclear projection model calculations several bands withK≧2 can be assigned tentatively. As a side result the half-life of169Ho was determined to be 4.7 ±0.2 min. 相似文献
20.
Theγ-radiation following the β? decay of73Ga has been studied. Singlesγ andγγ coincidence spectra were recorded with Ge(Li)-detectors. 17γ-rays were assigned to transitions in73Ge, where 11 excited levels are proposed. From logft values based onγ-transition intensities, spin and parity assignments for the levels were deduced. The half-life of73Ga was measured to (4.86±0.03) h. From allowedβ-transitions the ground state of73Ga was assigned 3/2?. 相似文献