Confinement effects of mandrel degradation in ICF target fabrication

Abstract

Understanding and further regulating the degradation of mandrel materials is a key aspect of target fabrication in inertial confinement fusion (ICF). Here, a quasi-one-dimensional confinement model is developed using a series of single-walled carbon nanotubes with varying diameters (Dm), and the degradation of poly-α-methylstyrene (PAMS) as a typical mandrel material is investigated under such confined conditions by using the combined method of quantum mechanics and molecular mechanics. In comparison to the isolated system, the calculations show that confinement can decrease or increase the energy barriers of PAMS degradation, which directly depends on Dm. Following which a clear exponential relationship between the degradation rate of PAMS and its own density is derived, indicating that the density of PAMS can be used to regulate mandrel degradation. This work highlights the important effects of confinement on degradation and provides a valuable reference for further development of polymer degradation technologies in ICF target fabrication and other fields.