同位素^(10)B靶的制备  

Preparation of Isotopic^(10)B Target

作　　者：樊启文[1] 王华[1] 孟波[1] FAN Qiwen;WANG Hua;MENG Bo(Department of Nuclear Physics,China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院核物理研究所,北京102413

出　　处：《原子能科学技术》2021年第3期550-554,共5页Atomic Energy Science and Technology

基　　金：国家自然科学基金资助项目(U1432246,11475264)。

摘　　要：为准确测量^(10)B(n,α)7Li和^(10)B(n,t2α)的反应截面,需制备质量厚度为50~350μg/cm^(2)的^(10)B靶。本文系统研究了同位素^(10)B靶的制备工艺,确定了“压片-烧结-蒸发”三步法制备^(10)B靶。研究了基片温度对^(10)B膜生长过程、结构和膜基结合力的影响,测试和分析了^(10)B靶的不均匀性。结果表明,利用间歇式静电聚焦微调电子轰击法制备同位素^(10)B靶,蒸发速率应低于0.02μg/(cm^(2)·s);灯丝平面与^(10)B柱的最佳距离为10.5~11 mm;生长的^(10)B膜随基片温度的升高而致密并逐步结晶,膜基结合力也更好,最佳基片温度约为300℃。对于尺寸为∅80 mm同位素^(10)B靶的制备,不均匀性可控制在10%以内。已经成功在Ta和Al基片上制备了厚度<350μg/cm^(2)的^(10)B靶用于核物理实验测量。In order to measure accurately the reaction cross sections of^(10)B(n,α)7Li and^(10)B(n,t2α),^(10)B targets with the thickness of 50-350μg/cm^(2)should be prepared.The preparation technology of isotopic^(10)B target was studied.The three-step method of“pressing-sintering-evaporation”was determined.The effects of substrate temperature on the growth process,structure and adhesion of^(10)B film were studied.The inhomogeneity of^(10)B target was also measured and analyzed.The results show that the evaporation rate of isotopic^(10)B target prepared by intermittent electrostatic focusing fine-tuning electron bombardment method should be less than 0.02μg/(cm^(2)·s).The optimum distance between filament plane and^(10)B column is 10.5-11 mm.The growth of^(10)B film is compact and crystallizes gradually with the increase of substrate temperature,and the adhesion between film and substrate is better.The optimum substrate temperature is about 300℃.For the preparation of isotopic^(10)B target with the size of∅80 mm,the inhomogeneity can be controlled within 10%.The^(10)B targets with the thickness less than 350μg/cm^(2)were successfully fabricated on Ta and Al substrates,and used in the measurements of nuclear physics experiments.

关 键 词：^(10)B靶 电子轰击 蒸发速率 基片温度 

分 类 号：O484.1[理学—固体物理]