Temperature distribution in polymeric films during ion beam irradiation

A simulation code is developed to investigate the cooling efficiency of a prototype ion beam irradiation system for surface modification. A linear type ion source has been used in this system. As a typical case, the temperature increase of poly-ethylene-terephthalate (PET) films during surface modification by the linear type ion source is simulated. In the simulation model, the PET film was placed on a sample holder made of aluminum, the thickness of PET was 50 mum and the thickness of sample holder was 1.5 mm. The incident beam energy was 1500 eV and beam current density was 1.0 A/m(2). Using this simulation model, the distribution of the temperature inside of the target and the sample holder was calculated. The relationships between the irradiation time and temperature increase at the: target surface was also calculated. The results showed that the behavior of the temperature increase was dominated by the cooling rate, and other parameters have comparatively less influence on temperature distribution. When the cooling rate was 5 W/m(2) K, the temperature increase at the target surface was 16.0 K, and when the cooling rate was 50 W/m(2) K, the temperature increase at the target surface was 6.4 K, for an irradiation time of 200 s. (C) 2002 American Institute of Physics.