Study of Gaseous Impurity Elements in Cavities with Use of Positrons and Positronium

利用正电子和正电子研究空腔中的气态杂质元素

• 批准号: 63550470
• 负责人: HASEGAWA Masayuki
• 金额: $ 1.22万
• 依托单位: Institute for Materials Research, Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63550470/
• 关键词: POSITRON; POSITRONIUM; CAVITY; VOID; RADIATION DAMAGE; VANADIUM; ZEOLITE; SEPIOLITE; グラファイト

In metals and semiconductors, there are cavities which are induced by bombardment of high energy particle or produced during sample preparation processes. In silicate compounds (zeolites and sepiolite) there are structural cavities. These cavities have been object of basic research because of their important roles in physical, mechanical and chemical properties such as dimensional stability of heavily irradiated metals, and catalytic behavior of synthetic zeolites.In this study positrons are used to investigate the interiors of cavities, especially state and behavior of gaseous element molecules within them.1) Positronium in cavities (voids) in vanadium Positron ACAR (angular correlation of annihilation radiation) and life measurements have been done on neutron-irradiated vanadium samples with controlled impurity contents of oxygen or carbon. It has been shown that contamination of voids with oxygen impurities, presumably on the void internal surface, leads to Ps formation, but not wit … More h carbon impurities. From the annealing behavior of narrow component due to para-Ps, the Ps formation increases with annealing temperature up to 600 ﾟC but subsequently decreases with increasing the temperature. This suggests that segregation of oxygen impurities onto the void surface up to 600 ﾟC followed by resolution into the matrix. Lifetime experiments shows a very rapid Ps ortho-para conversion rate and its large temperature dependence.2)Positron annihilation in zeolites and sepiolite. Positron annihilation ACAR measurements have been carried out for series of synthetic zeolite powders and single fibers of natural sepiolite. All of the samples showed marked narrow para-Ps peaks af the top of the ACAR curves. From a simple model calculation, the Ps atoms are found to exist as free particle in the structural cavities, such as the alpha-cages in the MS-3A zeolite and the 1-dimensional cavity channel in sepiolite. Oxygen molecules influence motion and reactions of Ps in these cavities.Cavities in neutron-irradiated nickel and stainless steel and in graphite have been studied by positron annihilation method. Less

在金属和半导体中，在样品中，有硅酸盐化合物（沸石和sepiolite）在样品中产生的空腔。化学性质类似于辐照金属的尺寸稳定性，Ze olites。测量已经进行了含氧或碳在无效的内部表面上进行的ITH控制的杂质含量。 PS的形成随着温度高达600°C的速度而增加，随后随着温度的增加而降低。 2）沸石中的ni灭和sepiolite。 MS-3A沸石和1-腔腔中的氧气分子在这些空腔中会影响PS的运动和反应

项目成果

Yasuo,Ito: Applied Physics. A45. 193-201 (1988)

伊藤康夫：应用物理学。

Masayuki Hasegawa: "Positronium in voids in metals(Jnuited Paper)" Positron Annihilation,Ed.by L.Dorikens-Vanpraet,M.Dorikens and D.Segers,World Scientific. 73-75 (1989)

长谷川雅之：“金属中空隙中的正电子（Jnuited Paper）”正电子湮灭，L.Dorikens-Vanpraet、M.Dorikens 和 D.Segers 编辑，世界科学。

Yoshimi,Tsuchiya: Proc.of the 8th Int.Conf.on Positron Annihilation,Gent,Belgium,23 Aug.-3 Sept.1988. (1989)

Yoshimi,Tsuchiya：第 8 届国际正电子湮灭会议记录，比利时根特，1988 年 8 月 23 日至 9 月 3 日。

E. Kuramoto, N. Kikuchi, D. Irisawa, M. Takenaka and M. Hasegawa: "Positron Annihilation ACAR Measurement of Neutron-Irradiated Fe-Cr-Ni Alloys" Positron Annihilation, Ed. by L. Dorikens-Vanpraet, M. Dorikens and D. Segers, World Scientific, p446-448, (19

E. Kuramoto、N. Kikuchi、D. Irisawa、M. Takenaka 和 M. Hasekawa：“中子辐照 Fe-Cr-Ni 合金的正电子湮灭 ACAR 测量” 正电子湮灭，Ed。

Eiichi Kuramoto: "Positron Annililation ACAR Measurement of Neutron-Irradiated Fe-Cr-Ni Alloys" Positron Annihilation,Ed.by L.Donkeus-Vanpraet,M.Dorikeus and D.Segers,World Scientific. 824-826 (1989)

Eiichi Kuramoto：“中子辐照 Fe-Cr-Ni 合金的正电子湮灭 ACAR 测量”正电子湮灭，L.Donkeus-Vanpraet、M.Dorikeus 和 D.Segers 编辑，World Scientific。