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.     

无氧下低浓度硫化氢在浸渍活性炭上的吸附研究

为了考察常温、无氧下浸渍Na2CO3改性、原料气相对湿度对活性炭吸附硫化氢的促进作用，用动态吸附法分别测试了不同湿度下原活性炭和浸渍活性炭对低浓度硫化氢的吸附，同时考察了温度对该吸附过程的影响。结果表明，吸附平衡数据均符合Freundlich吸附等温方程。与原活性炭相比，浸渍活性炭的孔容和比表面积略有降低，但对硫化氢的吸附能力却显著提高，说明硫化氢与浸渍剂在活性炭表面上发生了化学反应。相对湿度增加，活性炭和浸渍活性炭对H2S的吸附能力均显著增强。温度升高，平衡吸附量均略有下降。     

Gamma decay of the lowly excited states of 189Re

¹⁸⁹W activities were produced via the ¹⁹²Os(n, α) reaction using irradiation of isotopically enriched ¹⁹²Os metallic powder of ~100 mg/cm² with 14 MeV neutrons. The X-γ and γ-γ coincidence measurements were made so as to obtain γ rays from ¹⁸⁹W decay and its coincidence relations. A new simple decay scheme of ¹⁸⁹W including three γ rays of 210.2, 229.6 and 260.2 keV is proposed. Two new levels of ¹⁸⁹Re at 470.4 and 489.8 keV are assigned.     

Ba同位素的截面测量

用60MeV/u¹⁸O离子轰击天然铀靶,通过²³⁸U(¹⁸O,X)反应产生钡的放射性同位素.使用放射化学分离方法从被照射过的铀靶中分离出Ba,用HPGeγ射线探测器测量Ba样品的γ射线谱,经对所得时间累计谱的处理和分析得到了Ba同位素的产生截面,并观察到Ba同位素分布中的双峰分布现象.     

浸渍活性炭脱除低质量浓度H2S性能的研究

浸渍法制备了Na2CO3浸渍活性炭（IACⅠ）和一种高效脱硫剂（IACⅡ）。通过测定低质量浓度H2S在固定床上的穿透曲线，比较了原活性炭（AC）、IACⅠ和IACⅡ的脱硫效果。考察了原料气相对湿度，H2S质量浓度对穿透过程的影响。建立了固定床反应器一维轴向扩散模型模拟脱硫穿透曲线，并进行了数值求解。通过模型计算与实验测量穿透曲线拟合，确定了有效扩散系数等参数。结果表明，IACⅡ的脱硫效果最佳，其有效扩散系数较IACⅠ有所提高。提高相对湿度有利于增大硫容，但有效扩散系数略有降低。随着H2S入口质量浓度升高，有效扩散系数增大，穿透变快，硫容略有降低。     

β-delayed fission of 228Ac

The basic process of an exotic decay mode namely β-delayed fission is simply introduced. The progress status of the study in the world is essentialized. The observation of β-delayed fission of ²²⁸Ac is reported. The radium was radiochemically separated from natural thorium. Thin Ra sources in which ²²⁸Ac was got through ²²⁸Ra →β^－228Ac were prepared for observing fission fragments from β-delayed fission of ²²⁸Ac. They exposed to the mica fission track detectors, and measured by an HPGe γ-ray detector. The β-delayed fission events of ²²⁸Ac were observed and its β-delayed fission probability was found to be (5±2)×10^－12.     

230Ac β-延发裂变概率的测定

由60 MeV/μ ¹⁸O离子照射天然钍靶所引起的²³²Th-2p反应产生²³⁰Ra, 通过放射化学分离方法从被照射的靶中提取出镭元素并制成薄源, 经²³⁰Ra®²³⁰Ac 得到²³⁰Ac. 用云母裂变径迹探测器和PHGe γ 射线探测器对来自源中的裂变碎片和 γ谱进行记录和测量, 借助于所测得的两个裂变事件和 γ谱, 鉴别了β-延发裂变核²³⁰Ac, 得到了它的β-延发裂变概率为(1.19±0.85)×10^-8.