PRODUCTION OF POLARIZED 7Li ATOMIC BEAM IN STRONG MAGNETIC FIELD BY OPTICAL PUMPING

The production of a polarized ⁷Li atomic beam in a strong magnetic field was experimentally studied by laser optical pumping of a single ground hyperfine F level. It was shown that nearly complete negative and partial positive polarizations of ⁷Li atoms could be realized under appropriate conditions by this pumping scheme, which was in agreement with the rate equation calculations. Based on the analyses of transition probabilities, the maximum polarizations for various transitions and light polarizations were given.     

STUDY OF OPTICAL PUMPING OF ALKALI ATOMIC BEAM IN STRONG MAGNETIC FIELDS

We have gained a very comprehensive set of results for infrared diffraction (10.6μm wavelength) from fabricated single grooves of reflection with widths in the range of 5μm to 65μm. The experimental results show that the diffraction can still occur when the groove width becomes comparable to or less than the wavelength of the probing light. Variations of the diffraction intensities have a very regular sinusoidal relationship with the polarization angle of the incident light; and the diffraction intensities are the when the incident light is TM polarized. However, the diffraction intensities will be a minimum when the incident light is TE polarized; and the biger the diffraction angle, the higher the rate of change of the diffractive intensity with increasing polarization angle of the incident light.     

通过极化原子束的磁偏转实现激光同位素浓缩

本文描述一种通过极化原子束的磁偏转实现同位素和同质异能素浓缩的新方法。用具有不同频率和偏振的激光进行选择性光抽运,使束中两同位素的原子分别反向高度极化,然后使这些反向极化的原子在经过自旋选态磁铁后沿不同方向偏转,从而实现同位素浓缩。推算了此法的选择性和产量,与其他方法相比,讨论了其优缺点和可能的应用前景。提出了用锂或钾进行实验的方案。 关键词：     

利用强磁场剥离负氢离子获得中性束

本文用改进的微扰理论计算了在均匀磁场中高速运动的H~-离子的自离化寿命,讨论了H~-离子波函数的选择和连续态波函数的归一化,并用五参数Rotenberg-Stein波函数进行了具体的数值计算,与G.M.Stinson等人所得的实验结果进行了比较。     

85Rb灯对87Rb原子的光抽运

本文对用⁸⁵Rb灯不经滤光泡直接对⁸⁷Rb吸收泡的光抽运作了观测,得到了比传统的用⁸⁷Rb灯经⁸⁵Rb滤光泡对⁸⁷Rb吸收泡进行光抽运更强的基态0—0跃迁共振讯号。并在一定温度下观察到负的共振讯号。到目前为止,还不能对这种负的共振讯号作出解释。同时还测量了共振线宽和光频移。对在⁸⁷Rb原子频标中应用的可能性作了评述。 关键词：     

MEASUREMENTS OF RELAXATION OF SPIN POLARIZED 129Xe NUCLEI IN HIGH MAGNETIC FIELDS

We observed the NMR signal of low-pressure gas ¹²⁹Xe by laser enhanced method on an MSL-400 NMR spectrometer and measured nuclear spin relaxations of ¹²⁹Xe gas at various temperatures. The relaxation rate constant of ¹²⁹Xe-¹³³Cs spin exchange was obtained as (6.8±0.5)×10^-16cm^-3s^-1.     

离子导体LiCl(Al2O3)的核磁共振研究

本文报道了含分散第二相粒子的离子导体LiCl(或LiI)中⁷Li核磁共振的观测结果,测量了⁷Li核磁共振吸收谱线的线宽和自旋-晶格弛豫时间(T₁)。实验发现,在LiCl(Al₂O₃)中,⁷Li的核磁共振吸收谱线上叠加了一小峰,且随第二相粒子的类型、含量和温度而变化。⁷Li核磁共振信号的信噪比显著提高,自旋-晶格弛豫时间变短,且也随第二相粒子的类型、含量和温度而变化。结果表明,离子电导率的提高和附加小峰的出现都是由第二相粒子引起的,从而提出:靠近第二相粒子的LiCl界面附近的空间电荷区中高的离子传导是离子电导率提高和附加小峰出现的可能机理。 关键词：     

A microscopic multi-channel calculation for the reactions 7Li(p,p)7Li and7Li(p,n)7Be

Based on a refined resonating group method a microscopic multi-channel calculation for the reactions ⁷Li(p, p)⁷Li and ⁷Li(p, n)⁷Be has been performed. Diagonal S-matrix elements and differential cross sections are presented from the ⁷Li-p threshold up to E = 2.5 MeV c.m. and compared with experimental data.     

Break-up of 6Li and 7Li on tin and nickel nuclei

The break-up of the stable lithium nuclei on ⁵⁸Ni and ¹¹⁸Sn has been investigated in the bombarding energy range 12–24 MeV. The emerging α-particles have been analysed showing that the cross sections peak at the angle of grazing collisions. Inspection of the present data suggests the conclusion that several different reaction mechanisms contribute to the continuous spectrum of the α-particles.     

Optical-model analysis of 7Li + 25Mg and 7Li + 27Al elastic scattering at 89 MeV

The elastic scattering angular distributions for ⁷Li + ²⁵Mg and ⁷Li + ²⁷Al were measured at $\text{E(}{}^7\text{Li}\text{) = 89}\text{MeV}$ over angular ranges of 8–55° c.m. and 8–64° c.m. Previously published measurements for ^{24, 26}Mg at 89 MeV and ²⁴Mg at 34 MeV are reanalyzed. The cross sections were analysed using a 6-parameter phenomenological Saxon-Woods potential. No discrete ambiguities were found but the usual continuous ambiguities exist. The data were also analysed with double folded real potentials generated using the M3Y effective interaction. The folded potential must be multiplied by about 0.6 to fit the data. The extent to which ⁷Li optical-model potentials are determined and suggestions for further work on the normalization of the folded potential are discussed.     

Calculation of scattering parameters for ultracold ~6 Li-~7 Li elastic collisions

This paper theoretically studies the elastic scattering properties in a mixture of 6 Li and 7 Li atoms at cold and ultracold temperatures.Based on the constructed accurate interatomic potential of the triplet state for 6 Li 7 Li mixture by the mass scaling method,it calculates the interspecies s-wave scattering lengths and the p-wave scattering lengths by the variable phase method and the semiclassical method,respectively.The scattering length is in good agreement with the experiment.The partial-wave and total cross sections are also calculated and a rich resonance structure is found.     

原子束中慢波波谱的观察

分析了慢波中原子束波谱的特征多普勒增宽随着慢波结构的几何参数而变化的原因,给出了几种不同条件的驻波场慢波波谱,讨论了磁场对波谱的影响.实验上,观察到了波谱随慢波结构的几何参数的变化. 关键词：     

原子束在光定波场中的聚焦研究

建立了描述原子束在光定波场中聚焦行为的理论模型并通过数值计算给出原子在光驻波场中的运动轨迹,针对不同情况模拟了原子在基底上沉积的堆积图形.     

Electromagnetic properties of 7Li and 7Be in a cluster model

The electromagnetic properties of ⁷Li (⁷Be) are studied by using a microscopic α-t (³He) cluster model. Among the several properties are the Coulomb and magnetic form factors for the ground spin-doublet states of ⁷Li (⁷Be), density distribution radii, static moments and radiative transition probabilities. Provided that the stability conditions for the binding energies are satisfied for both the constituent nuclei α and t (³He), the calculated results are in good agreement with many available data. Several interesting differences are predicted between ⁷Li and ⁷Be.     

12C(7Li,t)16O和20Ne(d,6Li)16O反应的研究

本文把用于处理重离子引起的单粒子转移反应的Goldfarb-Buttle方法推广到多粒子转移反应。计算了¹²C(⁷Li,t)¹⁶O和²⁰Ne(d,⁶Li)¹⁶O反应,用了¹⁶O的全相干波函数,考虑了某些反冲因素,并将结果与实验作了比较。     

Nuclear reactions of 24 MeV 7Li on 10B

The charged-particle reaction channels accessible in the bombardment of ¹⁰B targets by ⁷Li nuclei of 24 MeV incident energy are investigated by measuring all ejectiles up to Be. Except for tritons, the reactions with light ejectiles proceed mainly via the formation of a compound nucleus, whereas some of the reactions with ejectiles heavier than the α-particle can be described by a direct mechanism.     

磁场误差对电子束能量调制的影响

 根据实测的磁场分布误差,对合肥同步辐射环上光学速调管中电子束能量调制的影响进了分析和讨论。结果表明磁场峰值误差对电子束能量调制的影响不大。