【作者】 席发元；

【导师】 陈熙萌；

【作者基本信息】 兰州大学 ， 粒子物理与原子核物理， 2009， 博士

【摘要】 绝缘材料微孔膜对低能高电荷态离子束的导向效应，在离子光学发展方面具有较好的应用前景。我们实验研究了低能O^q+离子束沿Al₂O₃微孔膜的导向效应。论文对微孔膜导向效应中出射束方向的具体表现做了深入研究，研究结果表明，离子束出射角相对于毛细孔偏转角表现出多样性，“导向”以及“出射角等于偏转角”仅是微孔膜导向效应的一种名义特征。离子穿透率与毛细孔偏转角的关系能够被类高斯函数拟合；获取了表征毛细孔导引能力的特征偏转角Ψ_c的数值，并与理论和其他小组的结果做了比较，从理论上分析了毛细孔导引能力与离子（E_p）/q值和不同绝缘材料之间的关系，结果表明，理论公式中的可调参数（Q_∞）/（c_e）因材料不同而不同；不镀导电层，作为微孔膜的一种不同的工作方式，表现出较强的离子导引能力；实验结果具有一定的可重复性。出射束宽度随微孔膜偏转角有波动；理论基本描述了出射束宽度与离子（E_p）/q值和不同绝缘材料之间的关系。实验发现了出射束方向与宽度变化之间的强关联；提出出射束角分布宽度是出射束方向连续变化累积结果的观点；认为绝缘材料较长的放电时间是出射束方向与宽度之间强关联的原因。更多还原

【Abstract】 Guiding effect of slow highly charged ions by capillary membranes ininsulators has excellent prospect in application at ion optics.Experimentally we studyguiding effect of slow O^q+ions through capillaries in Al₂O₃ membranes.We find that emission angles of the ions relative to the capillary tilt anglesexhibit diversity,i.e.“emission angles equalling the capillary tilt angles”as wellas“guiding”is just nominal character of the guiding effect.Relationship between the transmission rate and the capillary tilt angles can befitted by Gaussion-type function.We obtain the values of characteristic tilt angleψ_crepresentating the guiding ability of the capillries,and the results are compared withthe theory and that from others.The comparison shows that the adjustable parameter（Q_∞）/（C_e）in the theory equation varies with the materials,and that having no conductinglayers,as a different working form of the capillary membranes,exhibits stronger ionguiding ability with reproductivity of the experimental results to some extent.The experimental results also show that the angular widths of the emerging ionbeams fluctuate with the tilt angles of capillary membrane.The theory basicallydescribes the relationship between the angular widths and the insulating materials aswell as the ionic values of （E_p）/q.The experiments find strong correlativity of the directions with the widths of theemerging beams.We propose that the angular widths of the emerging beams are theaccumulative results of continuous variations of the emerging directions,and longdischarging time of insulators is the reason for the observed correlativity.更多还原