论文部分内容阅读
利用俄歇能谱“就地”定性、定量地测量了浸渍钡钨阴极(4.56∶1.44∶2)的蒸发成分和速率。得到的主要结果是:(1)老炼初期和寿命初期蒸发率可相差半个量级,前者的蒸发能为4.34eV,而后者为4.58eV;(2)蒸发物成分随阴极温度不同而变化,高温激活时,氧化钡在蒸发物中的比例缓慢减少,但Ca的蒸发增加,1250℃时,约占3.5％,在工作温度范围内,90％左右为金属钡,氧化钡约占9.3％;(3)与50年代蒸发测量相比,AES法得到的BaO蒸发量少得多,但与热力学理论计算的结果一致;(4)与AES计量的5∶3∶2,4∶1∶1阴极相比,所研究的阴极(4.56∶1.44∶2)的Ca蒸发量少得多,这是该阴极的特点;(5)逸出功测量和AST曲线都表明,当吸附了约1.5×10~(14)at./cm~2的钡时,多晶钨表面已建立一个由吸附原子形成的均匀的屏蔽场。
The composition and rate of evaporation of the impregnated barium-tungsten cathode (4.56: 1.44: 2) were qualitatively and quantitatively measured “in situ” using Auger energy spectra. The main results obtained are as follows: (1) The evaporation rate in the early stage of aging and the initial stage of life can differ by one and a half orders of magnitude, the former is 4.34eV and the latter is 4.58eV; (2) The composition of the evaporation varies with the cathode temperature , The proportion of barium oxide in the evaporation decreases slowly when high temperature is activated, but the evaporation of Ca increases, accounting for 3.5% at 1250 ℃. In the operating temperature range, about 90% is barium metal and barium oxide accounts for 9.3% ; (3) Compared with the evaporimetry in the 1950s, the BaO evaporation obtained by the AES method is much less, but it is consistent with the thermodynamic calculation. (4) Compared with the AES measurement of 5: 3: 2, 4: 1: The catholyte (4.56: 1.44: 2) studied had much less evaporation of Ca than the cathode, which was characteristic of the cathode; (5) Both the work function measurement and the AST curve showed that when the adsorption was about 1.5 × 10 ~ (14) at./cm ~ 2 barium, polycrystalline tungsten surface has been established by the adsorption of atoms formed a uniform shielding field.