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1.
用高自旋同质异能态次级束流线实验装置,对144Pm的高自旋同质异能态进行了快速分离,并做了γ射线的符合测量.结合γ射线激发函数和各向异性的测量结果,首次建立了奇—奇核144Pm的高自旋同质异能态的衰变纲图,其中19条高自旋能级和29条γ射线是由本工作指定的.离子γ射线关联测量确定了144Pm的高自旋同质异能态的半衰期大于2μs.通过系统性比较以及变形的独立粒子模型理论计算,指定了高自旋同质异能态的粒子组态可能为π(1h211/2d5/2)v(1i13/21h9/22f7/2),自旋宇称为Jπ=27+,并具有形变参数为β=-0.18的扁椭球形状.  相似文献   

2.
利用能量为 90— 1 0 5MeV的16 O束流 ,通过197Au( 16 O ,4n)反应研究了2 0 9 Fr的高自旋态能级结构 .进行了γ射线的激发函数、γ γ延迟符合及γ射线的角分布测量 .首次建立了由 2 1条γ射线构成的2 0 9Fr的能级纲图 ,其中包括一个半寿命为 ( 52± 2 0 )ns的同质异能态 .基于2 0 9Fr与2 0 8Rn低位能级结构的相似性 ,用一个h9/ 2 价质子与2 0 8Rn激发态的弱耦合解释了2 0 9Fr的低位能级结构 .  相似文献   

3.
在用14.8MeV中子轰击天然钨样品时,观察到了一条γ射线,其能量为291.7keV,以5.17±0.03秒的半衰期衰变。根据实验事实,我们假设~(183)W的5.2秒同质异能态衰变中除了已知的两条跃迁分支外,还存在11/2~ 11/2[615]→5/2~-3/2[512]态的另一条同质异能(E3)跃迁。计算了这条新跃迁分支的受阻因子,它与K~-禁戒同质异能跃迁的一般经验规则很好相符。  相似文献   

4.
利用能量为80MeV的18O束流,通过130Te(18O,5n)反应研究了143Nd的高自旋态能级结构.基于γγ延迟符合、γ射线的角分布及线性极化测量,首次发现了143Nd的一个半寿命为(35±8)ns,自旋和宇称为49/2+的同质异能态.用形变独立粒子模型探讨了此同质异能态的形成机制.  相似文献   

5.
在用14.8MeV中子轰击天然钨样品时, 观察到了一条γ射线, 其能量为291.7keV, 以5.17±0.03秒的半衰期衰变. 根据实验事实, 我们假设183W的5.2秒同质异能态衰变中除了已知的两条跃迁分支外, 还存在11/2+11/2[615]→5/23/2[512]态的另一条同质异能(E3)跃起迁. 计算了这条新跃迁分支的爱阻因子, 它与K禁戒同质异能跃迁的一般经验规则很好相符.  相似文献   

6.
用高自旋同质异能态次级束流线实验装置,对144Pm的高自旋同质异能态进行了快速分离,并做了γ射线的符合测量.结合γ射线激发函数和各向异性的测量结果,首次建立了奇—奇核144Pm的高自旋同质异能态的衰变纲图,其中19条高自旋能级和29条γ射线是由本工作指定的.离子γ射线关联测量确定了144Pm的高自旋同质异能态的半衰期大于2μs.通过系统性比较以及变形的独立粒子模型理论计算,指定了高自旋同质异能态的粒子组态可能为,自旋宇称为,并具有形变参数为β=-0.18的扁椭球形状.  相似文献   

7.
利用电介质的平均能带模型计算了 Gd Ba2 Cu3O7的化学键参数 ,得到 Cu(1 ) - O键的平均共价性为 0 .41 6,Cu(2 ) - O键的平均共价性为 0 .2 8。应用由共价性和极化率定义的化学环境因子计算了 57Fe在 Gd Ba2 Cu3O7中的 Mossbauer同质异能位移 ,确定了 57Fe在 Gd Ba2 Cu3O7中的价态和占位情况。  相似文献   

8.
黄小龙 《中国物理 C》2001,25(3):229-236
提出了中子反应同质异能态截面比的半经验公式.该公式含有一系统学参数,适应于产物核质量数44≤A≤197、同质异能态自旋0≤Jm≤12和基态自旋0.5≤Jg≤8的中子反应.在入射中子能量En<20MeV能区,对该系统学参数进行了系统学研究.通过获得的半经验公式和系统学参数,可以很好地再现已有实验数据,也可较好地预言无实验数据的同质异能态截面比或同质异能态截面.  相似文献   

9.
用参量化的方法推导了激光引起的原子核同质异能态共振跃迁的几率,并考虑了激光频率宽度的效应.进而研究了基于以下概念发展γ激光器的可能性:即用强的可见光激光将长寿命的同质异能素转换到能量上近似兼并的短寿命同质异能素,并使后者达到粒子数反转.在分析了同质异能态的粒子占有数随时间变化的基础上,数值计算了这一途径所需要的激光强度.  相似文献   

10.
用参量化的方法推导了激光引起的原子核同质异能态共振跃迁的几率,并考虑了激光频率宽度的效应.进而研究了基于以下概念发展γ激光器的可能性:即用强的可见光激光将长寿命的同质异能素转换到能量上近似兼并的短寿命同质异能素,并使后者达到粒子数反转.在分析了同质异能态的粒子占有数随时间变化的基础上,数值计算了这一途径所需要的激光强度.  相似文献   

11.
The reactione + e - e + e - 00e + e - 6 has been analysed using the full data sample taken with the Crystal Ball detector at the DORIS II storage ring at DESY. The 00 invariant mass spectrum is dominated by the ', for which we determine the radiative width (') to be (4.5±0.3±0.5)keV. Near 1.9 GeV/c2 we observe a second enhancement in the 00 mass distribution. Assuming that these events are created by the production and subsequent decay of a wide resonanceX(1900), we have investigated the decay modes, the invariant mass distributions of the 0 and 00 subsystems and the angular distributions of the final state mesons. We find that the data is best described byJ PC=2. For thisJ P assignment the resonance parameters are (X) BR(X)=(0.95±0.27±0.20) keV tot (X)=(221±92±44)MeV, andM(X)=(1881±32±40) MeV/c2.Deceased  相似文献   

12.
The very neutron-deficient isotope 133Sm was produced by irradiation of an enriched target of 96Ru with 40Ca and studied by using a helium-jet fast tape transport system in combination with X-γ and γ-γ coincidence measurements. A simple ( EC + β+) decay scheme of 133Sm was proposed for the first time. As a by-product 133Pr was produced simultaneously because of the 98-102Ru content of the ruthenium target. The half-life of a 11/2- low-lying isomeric state in 133Pr was measured to be 1.1±0.2 s. Received: 22 March 2001 / Accepted: 18 July 2001  相似文献   

13.
Nuclear spectroscopy studies of 51 133 Sb82 have been performed at the recoil fission product separators JOSEF and LOHENGRIN. A tentative level scheme has been established for this nucleus with one proton in addition to the doubly closed shell core132Sn. Two isomeric states with half-lives of 3 and 16 μs have been found at excitation energies of >4300 keV and 4526 keV, respectively. Lower limits of 15/2 are deduced for the spins of these levels. The h11/2 proton state is suggested at 2792 keV in agreement with the systematics of the lighter Z=51 isotopes and the heavier N=82 isotones. Several states have been observed between 4300 and 4600 keV which are probably due to the coupling of the single proton to core-excited states which have energies between 4000 and 4800 keV.  相似文献   

14.
It is described how the measurement of nγ-coincidences can be used to identify single-particle states in 133Sn. This method, in combination with the improved yields at ISOLDE, has facilitated firm determination of three excited single-particle states in 133Sn: p3/2, h9/2 and f5/2. The i13/2 state is not observed in this experiment and probably unbound, and the data did not allow a firm identification of the p1/2 state. The results are well reproduced in a Woods–Saxon calculation based on the data from the 208Pb region and taking into account the distance from β-stability of the 132Sn region. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

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17.
Underground nuclear weapon detonations release gaseous species into the atmosphere. The most interesting isotopes/isomers from the detection point of view are 131mXe, 133mXe, 133Xe and 135Xe. We have developed a method that employs high-precision Penning trap mass spectrometry at the JYFLTRAP facility, the University of Jyväskylä, to produce pure calibration samples of these isotopes/isomers. Among developments this work required a new mass resolution record of a few parts-per-million. Here the status and future plans of the project are reviewed.  相似文献   

18.
The project of the scintillation complex of the upgraded Tunka-133 detector is described. Software for simulation of recording and processing of events by the future scintillation part of the Tunka-133 detector is presented. Highlights of the simulation are given. Results of the simulation of extensive air showers using Aires software are listed.  相似文献   

19.
We present a theoretical analysis of numerous magnetically tunable Feshbach resonances measured by Chin et al. [preceding Letter, Phys. Rev. Lett. 85, 2717 (2000)] at fields of up to 25 mT. This analysis provides the most accurate characterization of the collisional properties of ground state Cs atoms currently available and clearly shows, in contrast to previous work, that Bose-Einstein condensation of 133Cs cannot be ruled out. The X1Sigma(+)(g) and a(3)Sigma(u) scattering lengths are constrained to (280+/-10)a(0) and (2400+/-100)a(0), respectively ( 1a(0) = 0.052 917 7 nm), and the van der Waals C6 coefficient to 6890+/-35 a.u.(1 a.u. = 0.095 734 5 x10(-24) &Jdot;nm(6)).  相似文献   

20.
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