Contamination is always troublesome in spacecraft development, but it has yet to be investigated because outgassing, transportation, deposition, and re-emission largely depend on spacecraft design. Designing spacecraft requires an accurate estimate of contaminant emission and deposition. Particularly for today’s sophisticated spacecraft, analytical tools would be indispensable—but current simulations need to be improved. Our study addresses the first phase in the occurrence of contamination: improving the outgassing model. We focused on diffusion-limited phenomena because the diffusion rate of outgassing molecules in materials is thought to be much slower than their desorption rate at the surface. A new outgassing test method and analytical procedure was originally devised for extracting the parameters of the diffusion model. In comparing the desorption and diffusion models, we developed a model for the emission of outgassing molecules based on the diffusion theory and updated some functions of Japan’s Spacecraft Induced Contamination Environment analysis software (J-SPICE). From this, we developed J-SPICE2 and installed the diffusion model to the software for calculating outgassing behavior.

中文翻译：

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基于扩散理论的污染物排放模型脱气测试方法

污染在航天器的开发中总是很麻烦，但是由于除气，运输，沉积和再排放在很大程度上取决于航天器的设计，因此尚待研究。设计航天器需要准确估算污染物的排放和沉积。尤其对于当今的先进航天器而言，分析工具将是必不可少的-但当前的仿真需要改进。我们的研究解决了污染发生的第一阶段：改进除气模型。我们关注扩散受限的现象，因为排气分子在材料中的扩散速率被认为比其在表面的解吸速率要慢得多。最初设计了一种新的除气测试方法和分析程序来提取扩散模型的参数。在比较解吸模型和扩散模型时，我们基于扩散理论开发了脱气分子排放模型，并更新了日本航天器污染环境分析软件（J-SPICE）的某些功能。据此，我们开发了J-SPICE2并将扩散模型安装到用于计算除气行为的软件中。