共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
The rare isotope ^236U has a half-life of 2.342(3)×107 years, and is produced principally by thermal neutron capture on ^235U. The isotopic atom ratio of ^236U/^238U depends on the integral thermal neutron flux received by the material of interest. ^236U is potentially useful as a "fingerprint" for indicating the presence of neutron-irradiated uranium usually originating from nuclear activity. By extracting negative molecular ion UO^- from the uranium oxide target, simulating the ^236U^16O^- beam transport with ^238U^16O^- and ^208Pb2^16O^- pilot molecular ion beam, transporting the ^236U-containing ion beam with a high resolution injection magnet analyzer and electrostatic analyzer system, and finally identifying and detecting ^236U with a time-of-flight detector (TOF), a method for AMS (Accelerator Mass Spectrometry) measurement of ^236U was established on the HI-13 Accelerator AMS system at China Institute of Atomic Energy. 相似文献
3.
Based on Weinberg-Salam theory the bremsstrahlung neutrino energy loss for nuclei ^24Mg, ^28Si,^32S, ^40Ca and ^56Fe are investigated in strong electron screening. Our results are compared with those of Dicus' and show that the latter are higher by 2 orders of magnitude in the density-temperature region of 10^8 g/cm^3 ≤p/μe ≤ 10^11 g/cm^3 and 2.5≤ T9≤ 4.5. On the other hand, the factor C shows that the maximum differences are 99.16%, 99.13%, 99.12%, 99.055%, 99.040% corresponding to the nuclei ^24Mg, ^28Si, ^32S, ^40Ca and ^56Fe. 相似文献
4.
5.
WANG Ji-Min DUAN Jun-Feng YAN Yu-Liang SUN Xiao-Jun ZHANG Jing-Shang 《理论物理通讯》2006,46(3):527-532
In n +^10B reactions, ^5He cluster emission has been discussed with the updated level scheme and the new optical model parameters. In this paper the reaction channels related to ^5He emission are listed in detail. By using the new reaction model for light nuclei, the double-differential cross sections of total outgoing neutrons for n + ^10 B reactions at En= 14.2 MeV have been calculated, and the results agree fairly well with the measurements. Particularly, in the energy-angular spectra the contribution from the 5He-emission to the total outgoing neutron double-differential cross sections has also been analyzed, and the partial energy-angular spectra of 60° at En= 14.2 MeV have been given. The calculated results indicate that once the 5He emission is taken into account, the fitting with the double-differential measurements of total outgoing neutrons at the low energy region could be improved. Therefore, to consider the ^5He emission properly in the reaction processes of light nuclei is necessary. 相似文献
6.
7.
傅元勇 周书华T. Koike S. Kinoshita Y. Ma Y. Miura K. Miwa Y. Miyagi K. Shirotori T. Suzuki H. Tamura K. Tsukada M. Ukai K. Futatsukawa K. Hosomi M. Kawai M. Mimori N. Terada N. Maruyama K. Aoki H Fujioka Y Kakiguchi T. Nagae D. Nakajima H Noumi T Takahashi T.N. Takahashi A. Toyota M. Dairaku T. Fukuda S. Minami W. Imoto S. Aiimura K. Tanida 《中国物理快报》2007,24(8):2216-2218
From the ^12 C(π^+,K^+)^12 AC reaction the γ -rays of 261.6±0.24 ke V(7/2^+ →5/2^+)and 1481.7±0.7 ke V(1/2^+ →5/2^+) of ^11 A B,and 2667.3±2.8 keV(1^- 2 → 2^- 1)of ^12 A C hypernuclei have been identified using a large germanium detector array Hyperball2 at K6 beam line of KEK. The observed energies of the transitions 1481.7keV and 261.6 keV are significantly different from the values predicted by the shell model using the △ and SN parameters determined from the ^7 △ Li data. 相似文献
8.
9.
Physics of Atomic Nuclei - The first cycle of measurements of the ratio of cumulative spectra of beta particles originating from the isotopes $${}^{235}$$ U and $${}^{239}$$ Pu undergoing... 相似文献
10.
11.
High-spin states of ^165Er were studied using the ^160Gd(^9Be, 4n)reaction at beam energies of 42 and 45 MeV. The previously known bands based on the ν5/2^-[523] and ν5/2^+[642] configurations have been extended to high-spin states. Electric-dipole transitions linking these two opposite parity bands were observed. Relatively large B(E1) values have been extracted experimentally and were attributed to octupole softness. 相似文献
12.
马龙 周小红 M.Oshima Y. Toh 张玉虎 郭应祥 雷相国 M.Koizumi A.Osa T.Hayakawa Y.Hatsukawa T.Shizuma M.Sugawara 《中国物理 C》2008,32(1):31-33
利用176Yb (18O, 4n)熔合蒸发反应,在束流能量95和88MeV下,研究了190Pt的激发态能级结构. 用12套带BGO反康普顿抑制的高纯锗探测器阵列进行了γ-γ-t符合测量. 基于实验测量结果,在14+(3413.6keV)的能态上建立了一个新的能级结构,并建议其组态为ni13/2-2 nh9/2-1nj (j=p3/2 or f5/2). 相似文献
13.
14.
The structure of Ne isotopes has been investigated by using deformed Skyrme-Hartree-Fock (SHF) method and BCS approximation. Especially the effect of tensor force on the halo structure of 29Ne and 31Ne is discussed. To this end, the tensor contributions are considered to the energy density function and the single particle potential in SHF theory. For comparison, four Skyrme interactions are used: SLy5 and SGII without tensor force, and SLy5+T and SGII+ T with tensor force. The results indicate that the inclusion of tensor force shows a more pronounced halo structure for 31Ne. 相似文献
15.
The two∑ ? reactions at rest∑ ? p→Λ 0 n and∑ ? p→Λ 0 n have been studied in order to determine the capture ratio $$r_c = \frac{{\sum ^ - p \to \sum ^0 n}}{{(\sum ^ - p \to \sum ^0 n) + (\sum ^ - p \to \Lambda ^0 n)}}$$ , theΛ 0-lifetime and the∑ ?-Λ 0 mass difference. The following results were obtained: $$\begin{gathered} rc = 0.474 \pm 0.016 \hfill \\ \tau _{\Lambda ^0 } = (2.47 \pm 0.08) \times 10^{ - 10} \sec \hfill \\ M_{\sum ^ - } - M_{\sum ^0 } = 81.64 \pm 0.09{{MeV} \mathord{\left/ {\vphantom {{MeV} {c^2 }}} \right. \kern-\nulldelimiterspace} {c^2 }} \hfill \\ \end{gathered} $$ The∑ ?-mass was determined from the range of the stopping∑ ?-hyperons,M ∑} =1197.19±0.32 MeV/c 2. 相似文献
16.
Determination of Atomic Number Densities of ^87Rb and ^3He Based on Absorption Spectroscopy
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The atomic number densities of ^87 Rb vapor and surrounding gas 3He in a sealed cubic cell were measured by sweeping the absorption line and fitting the experimental data with a Lorentzian profile. The absorption was carried out around the D1 transition at different temperatures. We compare our results for the number density for^87 Rb with the previous methods and calculate the fractional error to be less than 5% as well as the error for ^3He between this work and the density obtained from the filling procedure to be no more than 4.2% at 370K. In addition, we discuss the factors that contribute to the error, among which the cell temperature plays the most important role. 相似文献
17.
The exotic structures of the ground state of the mirror nuclei ^17Ne and ^17N are investigated by means of the asymptotic normalization coefficient (ANC) method to explore the role of the Coulomb interaction, The probebilities of a valence nucleon outside the binding-potential are P = 56.69±2.98/7.46% for ^17Ne and P = 45.51±2.32/5.81% for ^17N. The rms radii are (r^2)^1/2 = 5.06±0.11/0.30 fm and (r^2)^1/2=4.24±0.06/0.16 fm, respectively. The results obtained are nearly independent of the potential parameters. According to the halo occurrence conditions, it is suggested that ^17Ne is a two-proton halo and ^17N is a two-neutron skin. Moreover, two effects of the Coulomb interact-ion on the exotic structure are analysed. From the present results, the exotic structure of the nucleus in the proton-rich side is more obvious than that of its mirror nucleus because of the Coulomb interaction. 相似文献
18.
A. de Lesquen C.E. Allgower J. Ball M. Beddo J. Bystrický M. Combet Ph. Demierre G. Durand J.-M. Fontaine D. Grosnick R. Hess Z. Janout Z.F. Janout V.A. Kalinnikov T.E. Kasprzyk B.A. Khachaturov R. Kunne F. Lehar D. Lopiano V.N. Matafonov I.L. Pisarev A.A. Popov A.N. Prokofiev D. Rapin J.-L. Sans H.M. Spinka Yu.A. Usov V.V. Vikhrov B. Vuaridel A.A. Zhdanov 《The European Physical Journal C - Particles and Fields》1999,11(1):69-78
A polarized proton beam from SATURNE II, the Saclay polarized targets with Li compounds, and an unpolarized target were used to measure spin-dependent observables for protons scattered on bound nucleons. The beam and target polarizations
were oriented vertically. The analyzing power and the depolarization were determined at seven energies between 1.1 and 2.4 GeV. The spin correlation parameter was measured at only 1.1 and 1.6 GeV. Measurements with the target at 1.1 GeV provided data for scattering of polarized protons on neutrons in carbon. The quasi-elastic observables are compared with previous
elastic scattering measurements and at 1.1 GeV with predictions of phase shift analyses.
Received: 19 April 1999 / Published online: 28 September 1999 相似文献
19.
Determination of Astrophysical 13N(p,γ)^14O S-factors from the Asymptotic Normalization Coefficient of ^14C→^13C + n
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The angular distribution of the ^13C(d,p)^14C reaction is reanalysed using the Johnson-Soper approach. The squared asymptotic normalization coefficient (ANC) of virtual decay ^14 C →^13 C^14+ n is then derived to be 21.4±5.0 fm^-1. The squared ANC and spectroscopic factor (SF) of ^14O→^13N +p are extracted to be 30.4± 7.1 fm^-1 and 1.94 ± 0.45, respectively. The astrophysical S-factors and reaction rates of ^13N(p, γ)140 are determined from the ANC of ^14O → ^13N + P using the R-matrix approach. 相似文献