Dynamics of ion irradiation defects

We have investigated radiation enhanced sublimation of graphite and chemical sputtering of graphite under high flux beam irradiation （up to 10イイD122イイD1-2イイD1） to study the dynamics of ion irradiation defs and its effs on the above-mentioned erosion processes of graphite。已获得的结果如下：1。使用5 keV Ar beam with the flux up to 10的D121的D1-2的D1 s的D1-1的D1。It is found that as irradiation flux exceeds 10-D120-D1-2-D1-1-此flux dependence is much stronger than the previous low flux results （< 10_根据自内部扩散理论，通量对辐射增强型覆盖率的依赖可以被简化提供，因为下沉的内部辐射对低辐射通量有稳定的影响（< 10-D120-D1-2） ... More D1-1 D1） and vacancies for high irradiation flux （>10 D120 D1 m D1-2 D1 s D1-1 D1）.2。Measurements of chemically sputtered methane （CD型D24型D2） were made with 5 keV D型D3型（/）3型D3型beam irradiation by a quadrupole mass analyser installed in a differential pumping chamber。样品是异源图形（JG-430）、CFC图形（CX 2002）、硼掺杂图形（GB系列，硼含量0%至20%）和硅掺杂图形（TS处理图形）。它发现了在任何甲烷信号中提取最大值时的峰值温度，流量增加到约1000 K。此温度以前没有观察到（少于850 K），可能会考虑到高通量效应。在添加中， methane yield （methane signal divided by flux）没有显示flux依赖。这些结果与Roth等人制作的一种典型的化学分裂模型不一致。根据800 K温度的退火效应的假设，该假设对图形预防甲基组形成的影响。化学分裂的硼-掺杂的图形场被减少了大约3个因素，并用纯图形样本进行比较。用于硅掺杂的图形，其原子化约为1/1。化学探测器几乎被压抑了。Less（低）

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