排序方式: 共有51条查询结果,搜索用时 15 毫秒
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气体喷嘴反冲传输技术是继“跑兔”装置之后发展和完善起来的适合于短寿命核素研究的一种快速而有效的在线脱束方法。 它能够将短寿命核反应产物传输至远离高辐射区的低本底场所进行收集和测量。 该技术已在加速器和反应堆上得到了广泛的应用, 是一种研究核反应、 核谱学和合成与鉴别新元素、 新核素的一种不可缺少的基本实验技术和工具。 描述了气嘴系统的结构、 基本原理、 设计要求以及它的主要特性, 特别是对系统的气体动力学机制以及各种参数对系统特性的影响等进行了讨论。 最后, 综述了它在核物理、 核化学以及质谱学等领域的应用情况, 并且给出了几个应用的典型例子。 The gas jet recoil transport technique is developed and improved as a new rapid and effective on line and off beam method following “rabbit” apparatus in the study of short lives nuclei. It can transport the short half life nuclear reaction products far from high radioactive area for collection and measurement at low background area. This technique has been widely used in the researches with accelerator and reactor. It is indispensable basic experimental technology and tool applied to nuclear reaction, spectroscopy, as well as synthesis and identification of new elements and nuclei. The basic principle, structure, design requirement and main characteristics of gas jet system are described in this paper, especially the mechanism of gas dynamics and the effect of several parameters on the system properties are discussed. Finally, the applications of this technique in several fields such as nuclear physics, nuclear chemistry and mass spectroscopy etc. are comprehensively represented. Several typical applications are also illustrated. 相似文献
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The most neutron-deficient isotopes 215;216U were produced in the complete-fusion reaction 180W(40Ar, 4-5n)215,216U. Evaporation residues recoiled from the target were separated in-flight from the primary beam by the gas-filled recoil separator SHANS and subsequently identified on the basis of correlated -decay chains. Two -decaying states were identified in 216U, one for the ground state and the other for the isomeric state with 8+(h9=2f7=2) configuration. The -decay properties for 215;216U and the systematics of 8+ isomeric state in N =124,126 isotones were investigated. 相似文献
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分析了目前关于超重核研究的现状,结合现有的设备及条件,在合成259Db以后,下一次实验的目标核初步确定为107号元素的新同位素265Bh.描述了对MG转轮收集探测系统的实验检验结果.实验中成功地观察和测量了24Mg+232Th的产物252No的母子体的α衰变谱,为下一步合成265Bh完成了部分预实验工作.另外,也给出了下一个目标核的衰变特性的理论预言值,同时也选择了产生该目标核的弹靶组合及反应道,并对生成截面进行了粗略估计,给出了该核的可观测性产额及可行性分析. The present status of investigation on the surperheavy nuclei are analyzed. After 259Db synthesized, the next objective nuclide is determined to be265Bh, a new isotope of Z=107 element, according to our existing available equipment and conditions.The test result of the MG rotating wheel collection and detection system is described. The α decay spectra of mother daughter of the product252No from24Mg +232Th reaction are observed and measured successfully in this test experiment. It is regarde... 相似文献
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The restriction of the one dimensional (1D) master equation (ME) with the mass number of the projectile-like fragment as a variable is studied, and a two-dimensional (2D) master equation with the neutron and proton numbers as independent variables is set up, and solved numerically. Our study showed that the 2D ME can describe the fusion process well in all projectile target combinations. Therefore the possible channels to synthesize super-heavy nuclei can be studied correctly in wider possibilities. The available condition for employing 1D ME is pointed out. 相似文献
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A flow gas low-pressure multi-wire proportional chamber(LPMWPC)with an active area of 180 mm×80 mm has been developed for the flying time test of the recoil nuclei on super heavy nuclear experiments.The LPMWPC detector can be operated in single as well as double step operational modes.In the case of double step operational mode with a high gas amplification factor,signals fromα-particles reside well above the electronic noise.The gas leakage rate and time resolution obtained from theα239Pu source are shown and discussed at the condition of 3 mbar Isobutane gas.It was shown that the time resolution was better than 2.9 ns at the best work condition,and the detecting efciency was larger than 98%at the low energyαparticles.So the LPMWPC is fit to measure the flying time in the super heavy nuclear fragments experiment. 相似文献
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徐瑚珊 黄天衡 孙志宇 胡正国 詹文龙 周小红 黄文学 张宏斌 章学恒 甘再国 郑川 李君清 马新文 秦芝 肖国青 郭忠言 李智慧 张玉虎 靳根明 《原子核物理评论》2006,23(4):359-368
简单描述了超重核合成的历史与国际现状, 详细地介绍了近代物理研究所已经开展的研究工作及取得的成果, 并对近代物理研究所未来在超重核研究方面的研究计划进行了介绍。 The history and the international status of the super heavy nuclei synthesis are briefly described. The related research work carried out at the Institute of Modern Physics (IMP) has been reviewed. The prospect of the super heavy nuclei research at IMP has been introduced. 相似文献
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范红梅 吴晓蕾 郭俊盛 甘再国 秦芝 雷相国 董成富 徐华根 陈若富 张福明 郭斌 刘洪业 王华磊 谢成营 冯兆庆 郑勇 宋立涛 骆鹏 徐瑚珊 周小红 任中洲 靳根明 《中国物理 C》2005,(5)
主要介绍了合成和鉴别107号元素的新同位素265Bh的实验装置、实验方法以及实验结果.目标核265Bh是由能量为135MeV的26Mg离子轰击243Am靶,通过融合蒸发反应而产生.反应产物首先由He jet系统传输到装有数个探测器对的转轮收集测量系统,然后依靠母子核遗传关系通过观察新同位素和它们已知子核261Db和257Lr之间的α衰变的关联,来实现对新核素的鉴别.实验测得265Bh的α衰变能量为(9.24±0.05)MeV, 半衰期为0.94+0.70-0.31s.从该实验得出的265Bh的α衰变能量和半寿命能够与理论预言一致. 相似文献
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张玉虎 M.Oshima T.Morikawa T.Hayakawa Y.Toh 周小红 何建军 刘忠 甘再国 T.Shizuma M.Koizumi A.Osa J.Katakura Y.Hatsukawa M.Matsuda N.Shinohara T.Ishii H.Kusakari M.Sugawara K.Furuno T.Komatsubara T.Une 温书贤 竺礼华 王治民 许甫荣 《中国物理 C》2003,(4)
利用重离子熔合蒸发反应和在束γ谱学实验方法研究了双奇核176,178Ir和182 Au的高自旋态结构 ,在这 3个双奇核中观测到了基于πi13 2 νi13 2 准粒子组态下的转动带 .以能级间隔系统学为判据 ,对184Au核中πi13 2 νi13 2 转动带能级自旋进行了指定 .指出176,178Ir和182 ,184Au 4个双奇核的πi13 2 νi13 2 转动带在低自旋区均出现旋称反转 .对πi13 2 νi13 2 转动带旋称反转现象进行了定性的讨论 .用推转壳模型对πh9 2 νi13 2 带和πi13 2 νi13 2 带能级结构进行了理论研究 ,发现当采用形变和对力自洽计算后 ,从理论上可以定性地解释两个半退耦带出现的旋称反转现象 相似文献
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