Electron emission contributions to dark current and its relation to microscopic field enhancement and heating in accelerator structures
Electron emission contributions to dark current and its relation to microscopic field enhancement and heating in accelerator structures
复制标题
电子发射对暗电流的贡献及其与加速器结构中微观场增强和加热的关系
DOI：
10.1103/physrevstab.11.081001
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发表时间：
2008
影响因子：
--
通讯作者：
P. O'Shea
中科院分区：
文献类型：
--
作者：
K. Jensen;Y. Lau;D. Feldman;P. O'Shea
建立了热场发射、场增强和加热机制(诺丁汉和电阻)的易于分析的模型，并将其结合在一起，以估计伴随着粗糙度发展和增长的场和温度。在两个实验激励的例子中讨论了粗糙度尺寸与暗电流的关系。在诺丁汉和电阻加热的背景下，讨论了暗电流和加热的微观来源与击穿的假设关系。后者是用一般的热场方法估计的。用点电荷模型求出场增强因子。最后，利用热模型估算了材料的电阻率和导热系数随温度的变化关系。总而言之，这些模型表明，可能会出现这样的条件，即粗糙顶的温度可能经历增长并导致融化或破裂(或两者兼而有之)，而诺丁汉加热通常主导着阻性加热项。
Analytically tractable models of thermal-field emission, field enhancement, and heating mechanisms (Nottingham and resistive) are developed and combined to make estimates of the fields and temperatures that accompany the development and growth of asperities. The relation of asperity dimensions to dark current is discussed in two experimentally motivated examples. The hypothetical relation of microscopic sources of dark current and heating to breakdown is discussed in the context of Nottingham and resistive heating. The latter are estimated using a general thermal-field methodology. A point-charge model is used to find field enhancement factors. Last, a thermal model is used to estimate the temperature dependence of the resistivity and thermal conductivity. Together, these models suggest that conditions can arise in which the temperature at the apex of an asperity can experience growth and contribute to melting or fracture (or both), and that Nottingham heating generally dominates the resistive heating term.