The relationship between charge accumulation and scission of molecular chain in the proton irradiated PI

We evaluate the dielectric characteristic of polymeric materials for spacecraft irradiated by a high energy proton using results of space charge distribution and conduction current measurement under DC. From the results, we observed that space charge polarization was produced in the irradiated bulk and the conductivity is 10⁴ times larger than pristine sample. It is considered that those phenomena were produced due to the scission of molecular chain. Therefore, in this report, we try to find the evidence of scission of molecular chain by the XPS analysis, UV-vis and surface observation results.