Here, we report the study on degradation for a kind of ideal mandrel material called poly-α-methylstyrene based on the theoretical and experimental methods. First-principles calculations reveal two types of processes including depolymerization and hydrogen transfer induced chain scission. Between them, the energy barrier for former (0.68-0.82 eV) is smaller than that for most of the latter (1.39-4.23 eV). More importantly, reaction rates suggest that the former is fast while the latter is mostly slow, which can achieve 5-31 orders of magnitude difference at 550 K. Further, thermogravimetric experiment shows that the activation energy of 2.53 eV for degradation is between those of fast and slow processes, corresponding to the theoretical average value of multiple reaction paths. Thus, a mandrel degradation model combining fast and slow processes is established at the atomic level. Our work provides a direction for key technology of target fabricating in inertial confinement fusion research.
Zhu Yu, Liu Zheng, Yu Famin, Chen Qiang, Feng Wei, Zhan-Wen Zhang, Wang Zhigang. Mandrel degradation model of combined fast and slow processes[J]. High Power Laser Science and Engineering, , (): .
