Elucidation of the Two-Step Damage Formation Process of Latent Tracks in Poly(allyl diglycol carbonate), PADC: Role of Secondary Low-Energy Electrons
Elucidation of the Two-Step Damage Formation Process of Latent Tracks in Poly(allyl diglycol carbonate), PADC: Role of Secondary Low-Energy Electrons
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DOI：
10.1021/acs.jpcc.8b05341
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发表时间：
2018-09-13
影响因子：
3.7
通讯作者：
Yamauchi, Tomoya
中科院分区：
文献类型：
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作者：
Kusumoto, Tamon;Fromm, Michel;Yamauchi, Tomoya
本研究的目的是评估当聚（烯丙基二甘醇碳酸酯）（PADC）用作固态核径迹探测器时，低能二次电子降解聚（烯丙基二甘醇碳酸酯）（PADC）的机制。我们通过飞行时间质谱法测量了 5-30 eV 电子对各种 PADC 替代分子的三个单层厚膜的撞击所解吸的正离子和负离子，其中含有醚和/或羰基 (C=O) 部分。随着分子内裂解的进展，大多数阴离子产率随着入射电子累积数量（即注量）的增加而减少。相比之下，O-在入射能量 >15 eV 时的产率（与羰基损伤相关）随着注量单调增加。这一发现意味着羰基的裂解是在替代物内的其他含氧基团受损后发生的。目前的结果证实了之前假设的 PADC 在高能电子和 222 nm 紫外光子照射下的两步降解过程。更一般地说，这些结果强调了考虑低能二次电子在高灵敏度高能粒子探测器退化中的作用的重要性。
The aim of the present study is to evaluate the mechanisms by which secondary electrons of low energy degrade poly(allyl diglycol carbonate) (PADC) when it is used as a Solid State Nuclear Track Detector. We measured, by time-of-flight mass spectrometry, the positive and negative ions desorbed by the impact of 5-30 eV electrons on three monolayer thick films of various PADC surrogate molecules, which contained ether and/or carbonyl (C=O) moieties. As cleavages within the molecules progress, most anion yields are seen to decrease with an increasing cumulative number of incident electrons (i.e., fluence). In contrast, the yield of O- at incident energies >15 eV, which is associated with damage at a carbonyl group, increases monotonically with fluence. This finding implies that cleavage of carbonyl groups occurs after damage to other oxygen containing groups within the surrogates. The present result corroborates the previously postulated two-step degradation process in PADC irradiated with high-energy electrons and 222 nm UV photons. More generally, these results underline the importance of considering the role of low energy secondary electrons in the deterioration of high-sensitivity energetic particle detectors.