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1.
Using gaseous sources of Tc2O7 containing the radioactive isotopes94Tc,95Tc and96Tc, levels at 871.0keV (94Mo), 765.8, 820.6, 947.8, 1074.0keV (95Mo) and 778.3keV (96Mo) have been excited. From the effective cross sections for nuclear resonance scattering and from the lifetimes of the 947.8, 1074.0 and 778.3keV levels known from Coulomb excitation experiments the profiles of theγ-lines have been determined. A broadening of theγ-lines due to Coulomb explosion of the molecules has been observed. Making use of the line profiles, lifetimes ofΤ=(6.4±1.0) ps andΤ=(0.90 ± 0.20) ps have been determined for the 765.8 and 820.6keV levels, respectively. The angular distribution of the resonantly scattered radiation yields an amplitude ratioδ for the mixed M1 E2 765.8keV transition ofδ=0.14 ?0.009 +0.08 . TheB(E2) from a Coulomb excitation experiment and the lifetimeΤ from the present experiment yield ¦δ¦=0.07±0.01 for the 820.6keV transition. 相似文献
2.
P. von Brentano C. Fransen A. Gade A. Lisetskiy N. Pietralla 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):99-103
Due to the recent development of radioactive beam production, various direct reaction studies in reversed kinematics have
been made to investigate the behavior of the N = 20 shell closure in the neutron-rich region. Coulomb excitation, proton inelastic scattering, and fragmentation of unstable
nuclei have been studied with γ-ray detection.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: motobaya@rikkyo.ne.jp 相似文献
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V. Paar 《Zeitschrift für Physik A Hadrons and Nuclei》1974,271(1):11-16
The properties of94Mo and95Mo nuclei, which are typical representatives of N=52 and N=53 nuclei, respectively, are described in the cluster-vibrational field coupling model in natural representation (without parameter fitting). The interplay of few valenceshell neutrons and vibrational degree of freedom gives rise to the coexistence of quasivibrational, quasirotational, and clustering phenomena. 相似文献
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C. A. Kalfas A. C. Xenoulis E. Adamides S. Papaïoannou L. D. Skouras 《Zeitschrift für Physik A Hadrons and Nuclei》1979,292(2):153-158
The multipole mixing ratios of transitions from 6+ and 8+ states in94Mo, following the decay of94Tc, have been measured by means ofγγ angular correlations. The spin of the 2423.4 keV state, being important for the interpretation ofγ cascades feeding this level, has been firmly established as 6+ by a method in which the angular correlation data are utilized in a non-conventional way. Furthermore, properties of electromagnetic transitions in94Mo have been calculated in the shell model framework and are compared with the corresponding experimental quantities. 相似文献
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Pietralla N Fransen C von Brentano P Dewald A Fitzler A Friessner C Gableske J 《Physical review letters》2000,84(17):3775-3778
We identify a Jpi = 3(+)(ms) state in 94Mo. This identification is based on six M1 and E2 strengths and is the first identification of a 3(+)(ms) state from B(M1) and B(E2) values. The transition strengths were determined from the measurement of Doppler shifts, branching ratios, and E2/M1 mixing ratios, obtained from gammagamma directional correlations following the 91Zr(alpha,n) reaction and the beta(+) decay of (94)Tc(m). The interacting boson model agrees with the observations, which prove the 2(+) mixed-symmetry states to be a building block in nuclear structure. 相似文献
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利用束流能量为116MeV的59Co(35Cl,2p2n)90Mo反应布居90Mo的高自旋态.用10台反康普顿HPGe探测器组成的探测阵列进行γγ符合测量.通过多普勒展宽峰的形状分析测定90Mo高自旋态的寿命.在正宇称衰变系观察到增强的M1跃迁,推断I=13以上是扁椭形变.负宇称高自旋态具有大的B(E2)值,并随自旋增大而起伏变化.正、负宇称态之间的跃迁显示增大的E1跃迁,似有八极关联的可能.但是,90Mo并不处在理论预言的存在八极形变的核区内. 相似文献
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张玉虎 柳敏良G.deAngelis Zs.Podolyak 郭文涛 A.Gadea C.Ur N.Marginean C.Rusu R.Schwengner D.R.Napoli R.Menegazzo S.Lunardi D.Bazzacco T.Martinez M.Axiotis A.Gargano S.M.Lenzi F.Brandolini W.vonOertzen 《中国物理 C》2004,28(9):941-946
通过重离子融合蒸发反应^16O(^82Se 4n)^94Mo布局了^94Mo核的高自旋态.利用多探头探测器阵列GASP进行了在束γ测量,从而重新研究了^94Mo核的高自旋态能级结构.基于新发现的一些重要的连接跃迁,对^94Mo核的高自旋态能级纲图做了重要修改.将新的能级结构与壳模型计算进行了比较和讨论.结果表明要正确的描述^94Mo核的高自旋态(自旋值大于14)能级结构,应考虑价中子在d5/2,g7/2和h11/2轨道上的激发. 相似文献
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Ohkubo S 《Physical review letters》1995,74(12):2176-2179
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We have investigated the low-lying collective states and electromagnetic transitions in 94Mo within the framework of the interacting boson model. The influence of model parameters on the energy levels and electromagnetic properties has been investigated. The analysis of the obtained results and the parameter values predict that the 23+state is the lowest mixed symmetry state with pure F = Fmax - 1 in this nucleus. The calculated results predicate that the 25+ (two-Q-phonon) mixed symmetry state is closed to the J = 2+ at 2.870 MeV in the experimental data, and the 2.965 MeV state is the lowest mixed symmetry with J = 3+. 相似文献
11.
The γ-decays of the energy levels of 92Nb and 94Tc were measured following the 92Zr(p, n)92Nb and 94Mo(p, n)94Tc reactions. For 92Nb the γ-ray thresholds were measured and a detailed excitation function was obtained near the 93Zr ground-state isobaric analog resonance. Also, γ-γ coincidence measurements with two Ge(Li) detectors were made for both 92Nb and 94Tc. The coincidence measurements determined ten energy levels in 92Nb and two levels in 94Tc. A comparison with particle transfer reactions is used to elucidate the structure of 92Nb levels observed here but not seen in the transfer reactions. 相似文献
12.
N. N. Arsenyev A. P. Severyukhin V. V. Voronov 《Bulletin of the Russian Academy of Sciences: Physics》2013,77(4):462-465
The influence of coupling between simple and complex configurations on the probabilities of E2 and M1 transitions between vibrational quadrupole states is investigated. The finite rank separable approximation for the Skyrme effective forces is used. Properties of the low-energy spectrum for quadrupole excitations in 94Mo nucleus are considered. 相似文献
13.
We investigated the properties of low-lying states in ~(94)Mo within the framework of the proton-neutron interacting boson model(IBM-2), with special focus on the characteristics of mixed-symmetry states. We calculated level energies and M1 and E2 transition strengths. The IBM-2 results agree with the available quantitative and qualitative experimental data on ~(94)Mo. The properties of mixed-symmetry states can be well described by IBM-2 given that the energy of the d proton boson is different from that of the neutron boson, especially for the transition of B(M1, 4_2~+→ 4_1~+). 相似文献
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Burda O Botha N Carter J Fearick RW Förtsch SV Fransen C Fujita H Holt JD Kuhar M Lenhardt A von Neumann-Cosel P Neveling R Pietralla N Ponomarev VY Richter A Scholten O Sideras-Haddad E Smit FD Wambach J 《Physical review letters》2007,99(9):092503
High-energy-resolution inelastic electron scattering (at the S-DALINAC) and proton scattering (at iThemba LABS) experiments permit a thorough test of the nature of proposed one- and two-phonon symmetric and mixed-symmetric 2+ states of the nucleus 94Mo. The combined analysis reveals the one-phonon content of the mixed-symmetry state and its isovector character suggested by microscopic nuclear model calculations. The purity of two-phonon 2+ states is extracted. 相似文献
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We investigated the properties of low-lying states in 94Mo within the framework of the proton-neutron interacting boson model (IBM-2), with special focus on the characteristics of mixed-symmetry states. We calculated level energies and M1 and E2 transition strengths. The IBM-2 results agree with the available quantitative and qualitative experimental data on 94Mo. The properties of mixed-symmetry states can be well described by IBM-2 given that the energy of the d proton boson is different from that of the neutron boson, especially for the transition of B(M1; 4 2 + → 4 1 + ). 相似文献
16.
A. Kankainen V. S. Kolhinen V. -V. Elomaa T. Eronen J. Hakala A. Jokinen A. Saastamoinen J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》2012,48(4):47
Penning-trap measurements on stable 92, 94-98, 100Mo isotopes have been performed with relative accuracy of \(\ensuremath 1\cdot 10^{-8}\) with the JYFLTRAP Penning-trap mass spectrometer by using 85Rb as a reference. The Mo isotopes have been found to be about 3keV more bound than given in the Atomic Mass Evaluation 2003 (AME03). The results confirm that the discrepancy between the ISOLTRAP and JYFLTRAP data for 101-105Cd isotopes was due to an erroneous value in the AME03 for 96Mo used as a reference at JYFLTRAP. The measured frequency ratios of Mo isotopes have been used to update mass-excess values of 30 neutron-deficient nuclides measured at JYFLTRAP. 相似文献
17.
T. Loarer J. Gunn J. L. Lachambre E. Gravier C. Boucher K. H. Finken M. Lehnen G. Mank S. Jachmich H. Van Goubergen G. Van Oost 《Czechoslovak Journal of Physics》2001,51(10):1021-1031
Particle collection by the ALT-II belt limiter in the TEXTOR-94 tokamak is exclusively limited to the parallel outflux because the scoop walls that are oriented parallel to the field lines obstruct the poloidal E×B mass flow. With normal B
tor direction (E×B towards the scoops), a threefold decrease of plenum pressure is measured during negative biasing, while with reversed B
tor (E×B away from the scoops), a 60% pressure increase is observed. This behaviour is exactly opposite to that observed in X-point divertors. A simple fluid model explains this apparent contradiction, and gives good quantitative agreement with measurements of the parallel Mach number in the SOL. The essential physics is governed by the Bohm-Chodura criterion. 相似文献
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Liquan He Fei Hong Yong Li 《International Journal of Infrared and Millimeter Waves》1996,17(2):297-303
This paper describes a kind of low insertion loss phase-shift-keying modulators used in 94GHz digital communications systems. A BPSK modulator with a insertion loss lower than 3.8dB has been achieved by connecting a circulator and a fin-line PIN diode phase shifter in series. The bandwidth is 2.5GHz given a phase error of ±50. The circuits and experimental results are also given out. 相似文献
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