单次分子镀法制备部分La系及~(238)U靶的实验研究

采用单次分子镀方法研究了异丙醇-硝酸体系中电流密度、分子镀持续时间及两极间距离对镀层性能和电沉积效率的影响,确定了制备La,Sm,Eu,Gd,Tb靶及238U靶的最佳工艺条件。因制备的靶不同,电流密度一般介于2—8mA/cm2之间,两极间最优距离为3cm,分子镀1h,用分光光度法测定各靶的沉积效率均高于85%。利用扫描电子显微镜(SEM)对部分靶的表面形貌分析后发现靶面结构均匀致密。目前制得的Gd靶和Tb靶已用于中国科学院近代物理研究所加速器SFC低能核化学终端上,利用19F束流轰击,分别产生了Ta和W的短寿命同位素,从而成功完成了Db(Z=105)及Sg(Z=106)的模型试验。

Experimental Study on Preparation of Some Lanthanide and 238U Targets by Using Single-cycle Molecular Plating Method

Preparation of La, Sm, Eu, Gd, Tb and 238U targets from the mixture of isopropanol and nitric acid solution are studied by using single cycle molecular plating technique. To determine the optimum conditions for the deposition process, the effect of current density, deposition time and distance between the two electrodes on the quality and electrodeposition yield of the target films are investigated individually. Depending on the deposited metal, the current densities are found to be 2—8 mA/cm2 and the suitable distance between the two electrodes is 3 cm. With the spectrophotometry method, the electrodeposition yields for all the targets prepared are found to be higher than 85% after one hour’s deposition. The composition and morphological structure of some targets are characterized by scanning electron microscope(SEM) and it can be seen that the surface of the targets are uniform and intact. Short lived isotopes of Ta and W were produced from natural Gd and Tb targets bombarded by 19F beam at the SFC low energy radiochemical terminal of Institute of Modern Physics, Chinese Academy of Sciences, respectively, and successfully applied in the model experiment of Db(Z=105) and Sg(Z=106).