One-equation, two-equation and kinetic theory: Laser pulse heating

In the present study, comparisons of electron kinetic theory predictions wi th results of two-equation and one-equation models are made. The numerical solutions for all models employed are introduced for exponentially decaying and step input intensity pulses. The closed form solution for the electron kinetic theory approach is obtained for the exponentially decaying pulse. The study is extended to include comparisons of the closed form solution of the kinetic theory approach with the analytical solutions previously obtai ned according to the Fourier theory. It is found that all the models consid ered result in similar temperature profiles inside and at the surface of th e substrate for laser pulses up to 10(-9) s. As the pulse length reduces fu rther (<10(-9) s) and intensity increases (>10(13) W/m(2)), the kinetic the ory predictions deviate considerably from the Fourier theory results.