Influence of Sample Temperature on the Process of Hot Spot Formation and Degradation after Powerful Laser Pumping

Abstract

The degradation of a hot spot obtained near one of the surfaces of a thin crystal plate of anthracene at helium temperatures is investigated. The experimental results are discussed in terms of the local thermal conductivity with both specific heat and thermal conductivity as well-known functions of temperature. A good agreement between experimental results and model calculations is achieved. Analyzing the results of calculations a conclusion is drawn on the strong influence of sample temperature on the process of hot spot formation immediately after laser pumping. The role of the sample defectiveness i s also discussed. The solution of the non-linear thermal conductivity equation used to describe experimental results is analyzed. It was found that initial conditions strongly affect the time evolution of the hot spot width. B Damof pa6OTe UccneAyeTca AerpaAauXa ropmero nmHa nonygemoro B~J I U~M O A H O~~