宽带泵浦激光的聚焦位置对SRS发生过程的影响

 结合SRS实验,重点研究了聚焦位置对Raman介质中的物理过程、Stokes光的输出特性的影响,比较了SRS阈值和转换效率的实验结果与理论预期。     

K_s~0重建及其寿命测量在BESⅡ上的研究

在BESⅡ上利用Bhabha,dimu事例确定了BEPC束流对撞中心位置,并以此为初级顶点研究了次级顶点的重建,改进了原有次级顶点重建程序,在此基础上选择 事例,测量了Ks0的寿命,并利用50MJ/ψ数据测量了Ks0的单举质量谱,最后还利用MC研究了Ks0质量的1C拟合.     

二次型复折射率介质中的光导现象

本文讨论了n(z,r)=n_0(z)+n_2(z)r~2/r_e~2型复折射率介质中的激光传输问题,给出了激光传输参数(光束半径和波阵面曲率)的演化公式。指出只要存在一定大小的n_(21),在传输过一段特征距离z_c之后,将出现完全光导(即自相似模的传播),而且自相似模是激光体系的特征模式。其传输参数只与n_2有关,而与激光初始参数无关。自相似模必定是高斯球面波,而不是高斯平面波。     

Determination of the ~(12)C(p, γ)~(13)N reaction rates fromthe ~(12)C(~7Li,~6He)~(13)N reaction

The angular distribution of the 12C(7Li,6He)13N reaction at E(7Li) = 44.0 MeV was measured at the HI-13 tandem accelerator of Beijing, China. The asymptotic normalization coefficient (ANC) of 13N → 12C + p was derived to be (1.64 ± 0.11) fm-1/2 through the distorted wave Born approximation (DWBA) analysis. The ANC was then used to deduce the astrophysical S (E) factors and reaction rates for the 12C(p,γ)13N direct capture reaction at energies of astrophysical relevance.     

Single-particle resonances in a deformed relativistic potential

The positive-parity single-neutron levels in an axially-deformed relativistic quadrupole Woods-Saxon potential are analyzed. Neutron states are obtained as the solutions of the corresponding single-particle Dirac equation, using the coupled-channels method in the coordinate space. The evolution of the levels close to the continuum threshold and, in particular, the occurrence of singleneutron resonant states as the functions of the axial deformation parameter 0 β 0.5, are examined using the eigenphase representation. Calculations are performed for different values of the radius of the potential (R/r 0 ) 3 , corresponding to a variation of the mass number A.     

Mobile Rayleigh Doppler wind lidar based on double-edge technique

<正>We describe a mobile molecular Doppler wind lidar(DWL) based on double-edge technique for wind measurement of altitudes ranging from 10 to 40 km.A triple Fabry-Perot etalon is employed as a frequency discriminator to determine the Doppler shift proportional to the wind velocity.The lidar operates at 355 nm with a 45-cm-aperture telescope and a matching azimuth-over-elevation scanner that provides full hemispherical pointing.To guarantee wind accuracy,a single servo loop is used to monitor the outgoing laser frequency to remove inaccuracies due to the frequency drift of the laser or the etalon.The standard deviation of the outgoing laser frequency drift is 6.18 MHz and the corresponding velocity error is 1.11 m/s.The wind profiles measured by the DWL are in good agreement with the results of the wind profile radar(WPR).Evaluation is achieved by comparing at altitudes from 2 to 8 km.The relative error of horizontal wind speed is from 0.8 to 1.8 m/s in the compared ranges.The wind accuracy is less than 6 m/s at 40 km and 3 m/s at 10 km.     

Lepton-number-violating decays of singly-charged Higgs bosons in the type-（Ⅰ＋Ⅱ ） seesaw model

The lepton-number-violating decays of singly-charged Higgs bosons H^± are investigated in the minimal type-（ Ⅰ＋Ⅱ ） seesaw model with one SU（2）L Higgs triplet △ and one heavy Majorana neutrino N1 at the TeV scale. We find that the branching ratios B（H^＋ → 1α^＋υ^-） （for α = e,μ,τ） depend not only on the mass and mixing parameters of three light neutrinos υi （for i = 1, 2, 3） but also on those of N1. Assuming that the mass of N1 lies in the range of 200 GeV to 1 TeV, we figure out the generous interference bands for the contributions of υi and N1 to B（H^＋→ 1α^＋υ^-）. We illustrate some salient features of such interference effects by considering three typical mass patterns of υi, and show that the relevant Majorana CP-violating phases can affect the magnitudes of B（H^＋→ 1α^＋υ^-）） in this parameter region.     

Systematic studies on α-decay half-lives for super heavy nuclei

Radioactive decay of super heavy nuclei via the emission of α-particles has been studied theoretically in the preformed cluster model （PCM）. The nucleus-nucleus （NN） potential is obtained by double folding the density distributions of the α-particle and the daughter nucleus with a realistic effective interaction. The M3Y effective interaction, supplemented by a zero-range pseudo-potential for exchange term, is used to calculate the NN potential. The α decay half-lives for 317 nuclei at Z=102 120 are performed in the PCM framework with the theoretical Q values extracted from the MSller-Nix-Kratz and Liran-Marinov-Zeldes mass tables and are compared with the experimental data. The calculated results are also compared with those obtained by using Q values from the Muntian-Hofmann-Patyk-Sobiczewski and Myers-Swiatecki mass estimates.     

Design of a PXR experiment based on the NCEL

Parametric X-ray Radiation （PXR） can be used as a novel, quasi-monochromatic energy-tunable and high-yield X-ray source. It is produced at the Bragg angle by a relativistic electron beam passing through the periodic structure of crystal materials. This article concerns the PXR experiment using low energy electrons （10 MeV） from NCEL （Novel Compact Electron-Linac）. The difficulty of the experiment is to distinguish the PXR photons form the background. The design of the experiment relies mainly on the yield of PXR, the Bremsstrahlung background of the X-rays and the capability of the detector.     

Primary result of ~(236)U measurement with accelerator mass spectrometry at CIAE

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 236U16O- beam transport with 238U16O- an...