THERMAL EFFECTS INDUCED IN SOLID TARGETS BY LASER RADIATION

Abstract

This thesis presents a theoretical treatment to study the the1mal effects induced in solid targets by laser radiation. The study consists of four main parts as follows:

Tlte first part: Represents survey of literature on themal effects induced in solid targets by laser radiation. It considers the experimental and theoretical trials to solve the heating problem with• different and initial boundary conditions. One-phase and multi­ phase problems are also indicated. A review of the main experimental and theoretical results obtained by some authors are revealed.

The second part: Represents a trial to predict a semi-classical mathematical expression to represent a laser pulse shape, characterized by the following parameters: The maximum power density of the incident pulse (qmax) (iV/m2 . Pulse time duration (6t), sec. and The time collapsed (6to) sec, to reach qmax• Changing the values of these parameters one gets different pulse shapes, that to be considered in the present study.

The third part: Represents a theoretical attempt to study the problem of heating a finite homogeneous slab of material induced by time-dependent laser irradiance q(t) with different pulse shape parameters. Two cases are considered: i) For a finite slab with insulated rear surface, and ii) For a finite slab considering cooling conditions at the rear surface.