Determination for β-delayed fission probability of 230Ac

The 230Ra has been produced via 232Th-2p reaction induced by 60 MeV/u 18O ion irradia-tion of natural thorium. The radium was radiochemically separated from the mixture of thorium andreaction products. Thin Ra sources in which 230Ac was got through 230Ra β- → 230Ac were pre-pared for observing fission fragments from β-delayed fission of 230Ac. The sources were exposedto the mica fission track detectors and measured by the HPGe γ detector. The precursor 230Ac wasidentified by means of observed two fission events as well as γ spectra, and the β-delayed fissionprobability of 230Ac was obtained to be (1.19±0.85) × 10-8.     

新重丰中子核237Th的合成和鉴别

用14MeV中子照射(NH₄)₂U₂O₇粉末,通过²³⁸U(n,2p)²³⁷Th反应产生了新的重丰中子同位素²³⁷Th,并用放射化学方法分离了它.借助于跟踪其子体²³⁷pa的γ射线的时间序列谱首次鉴别了这个新活性.利用递次衰变分析程序得到了²³⁷Th的半衰期为5.0±0.9min.另外,发现了一条能量为35.1±0.3keV T_1/2=5.0±1.1min的新γ射线并指定它为²³⁷Th衰变.     

中能12C+197Au产物中Ir的同位素分布观测

以¹²C(47MeV/u)+¹⁹⁷Au靶,通过化学分离及γ谱学方法获得了Ir和Pt同位素产额. 用测到的Pt累积产额对相应Ir同位素做了照射期内母体衰变修正,从而获得了很好的Ir同位素分布. 讨论了A>170丰中子核产生截面、截面的Q_gg系统性和剩余激发能的问题.     

超铀区缺中子新同位素~（235）Am的合成与鉴别

用３５ＭｅＶ质子轰击同位素靶２３８Ｐｕ，通过２３８Ｐｕ（Ｐ，４ｎ）２３５Ａｍ反应，合成了新的缺中子同位素２３５Ａｍ．利用Ｈｅ－ｊｅｔ及毛细管传输技术收集反应产物，然后用放射化学法除去产物中的裂变碎片并分离出Ａｍ活性．根据观测到的２３５Ｐｕ的衰变Ｙ及ＮＰ的特征Ｘ射线的生长－衰变行为和Ｘ－Ｙ符合测量，肯定了２３５Ａｍ的首次合成，测得２３５Ａｍ的半衰期为１５±５ｍｉｎ．     

186mTa的鉴别

通过14 MeV中子引起的¹⁸⁶W(n,p)反应, 生成了^186mTa和¹⁸⁶Ta. 借助于对已知¹⁸⁶Ta的γ射线的观测, 鉴别了未知的^186mTa, 并测定其半衰期为1.5±0.1 min.     

新重丰中子同位素^239Pa的合成

本文简述了新重丰中子同位素＾２３９Ｐａ的首次合成和鉴别，并测定其半衰期为１０６＋３０ｍｉｎ。     

实验测定183Os的QEC值

用39MeV-α粒子轰击天然钨靶产生了¹⁸³Os测量了¹⁸³Os衰变的γ-β符合谱,确定了β⁺能谱的端点能量.最终提取出 衰变的QQ_EC值:Q_EC=2.24±0.10MeV,与系统学的估计值;2.30±0.10MeV在误差范围内相符.     

新丰中子同位素:186Hf

在兰州重离子加速器(FDUL)上,用60MeV/μ ¹⁸O离子轰击厚天然钨靶,通过多核子转移反应产生¹⁸⁶Hf. 使用放射化学分离技术从钨和反应产物混和物中分离出铪,并由HPGe探测器测量铪样品的活性.观测到了¹⁸⁶Hf的子体¹⁸⁶Ta的737,5keVY射线的增长、衰变行为,结果表明,本实验首次合成并鉴别了新丰中子同位素¹⁸⁶Hf,测得它的半衰期为(2.6±1.2)min.     

新同位素235Am的产生与鉴别

一种缺中子新同位素２３５Ａｍ通过２３８Ｐｕ（ｐ,４ｎ）２３５Ａｍ反应而产生．产物借助Ｈｅ－ｊｅｔ系统的传输,快化学分离以及γ、Ｘ射线和γ－Ｘ（γ）符合测量等得到鉴别,测得其半衰期为１５±５ｍｉｎ． A new neutron deficient isotope 235 Am was produced via 238 Pu(p,4n) 235 Am reaction. The products were identified by means of the transporting of He jet system, separating of rapid radiochemical method and measuring of γ and X rays as well as X γ coincidence. The measured half life of 235 Am is 15±5min.     

新重丰中子同位素239Pa的合成

本文简述了新重丰中子同位素２３９Ｐａ的首次合成和鉴别,并测定其半衰期为１０６±３０ｍｉｎ． This paper reports that the new heavy neutron-rich isotope 239Pa has been observed for the first time and its half life has been determined to be 106±30min.