Dynamics of ion irradiation defects

离子辐照缺陷动力学

基本信息

批准号：
09680492
负责人：
UEDA Yoshio
金额：
$ 1.6万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09680492/
关键词：
ion irradiation defects radiation enhanced sublimation chemical sputtering high flux graphite boron-doped graphite silicon-doped graphite flux dependence 高粒子束ビーム

项目摘要

We have investigated radiation enhanced sublimation of graphite and chemical sputtering of graphite under high flux beam irradiation (up to 10ィイD122ィエD1 mィイD1-2ィエD1sィイD1-1ィエD1) to study the dynamics of ion irradiation defects and its effects on the above-mentioned erosion processes of graphite. The obtained results are as follows :1. Radiation enhanced sublimation of isotropic graphite was investgated with 5keV Ar beam with the flux up to 10ィイD121ィエD1mィイD1-2ィエD1sィイD1-1ィエD1). It is found that as irradiation flux exceeds 10ィイD120ィエD1mィイD1-2ィエD1sィイD1-1ィエD1 erosion yield decreases rapidly with flux as ΦィイD1-0.26ィエD1 (Φ : flux). This flux dependence is much stronger than the previous low flux results (< 10ィイD120ィエD1mィイD1-2ィエD1sィイD1-1ィエD1, ΦィイD1-0.1ィエD1). According to self-interstitial diffusion theory, flux dependence of erosion yield of radiation enhanced sublimation might be elucidated provided that sinks for interstitials are stable defects for low irradiation flux (< 10ィイD120ィエD1mィイD1-2 … More ィエD1sィイD1-1ィエD1) and vacancies for high irradiation flux (>10ィイD120ィエD1mィイD1-2ィエD1sィイD1-1ィエD1).2. Measurements of chemically sputtered methane (CDィイD24ィエD2) were made with 5 keV DィイD3+(/)3ィエD3 beam irradiation by a quadrupole mass analyser installed in a differential pumping chamber. Samples were isotropic graphite (JG-430), CFC graphite (CX2002), boron-doped graphite (GB series, boron content 0% to 20%), and silicon-doped graphite (TS processed graphite). It is found that peak temperature at which methane signals took maximum increased with flux up to about 1000 K. This temperature was not observed previously (less than 850 K) and could be considered as a high flux effect. In addition, methane yield (methane signal divided by flux) did not show flux dependence. These results are not consistent with a typical chemical sputtering model made by Roth et al. under the assumption that the annealing effects of graphite prevents methyl group formation above the temperature of 800 K. Chemical sputtering yield of boron-doped graphite is reduced by about a factor of 3 compared with pure graphite samples. For silicon-doped graphite with the atomic ration of about 1/1. Chemical sputtering was almost suppressed. Less

我们研究了石墨在高通量束辐照（高达10 D122 D1 D1 D1 D1 D1 D1 D1）下的辐射增强升华和化学溅射，以研究离子辐照缺陷的动力学及其对上述腐蚀过程的影响。得到的结果如下：1．各向同性石墨的辐射强化升华。用5keV Ar束，通量高达10D121D1-2D1sD1-1D1)进行研究，发现当辐照通量超过10D120D1m D1-2 D1s D1-1 D1时，侵蚀产率随通量快速下降。 ΦD1-0.26D1（Φ：通量）比之前的低通量结果强得多（< 10D120D1mD1-2D1sD1-1 根据自间隙扩散理论，辐射增强升华的侵蚀产率的通量依赖性可能是阐明了间隙的汇是低辐照通量（< 10D120D1mD1-2 … 更多 D1-1D1）的稳定缺陷和高辐照通量（>10 D120 D1m D1-2 D1s D1-1 D1）的空位。2. 测量化学溅射甲烷（CD-D24-D2）是通过安装在差动泵室中的四极质量分析仪以 5 keV D-D3+(/)3-D3 束照射制备的，样品为各向同性石墨（JG-430）、CFC 石墨。（CX2002）、掺硼石墨（GB系列，硼含量0%至20%）和硅掺杂石墨（TS 处理的石墨）发现甲烷信号达到最大值的峰值温度随着通量增加到约 1000 K。该温度以前没有观察到（小于 850 K）。此外，甲烷产量（甲烷信号除以通量）并未表现出通量依赖性。这些结果与 Roth 等人假设的典型化学溅射模型不一致。石墨的退火效应可防止在 800 K 温度以上形成甲基。与原子比约为 1/ 的纯石墨样品相比，硼掺杂石墨的化学溅射产率降低了约 3 倍。 1.化学溅射几乎被抑制。