Thermochemical heat of ablation of solid carbon

Abstract

The thermochemical heat of ablation of carbon, H_A, is usually set equal to 32 kJ/g as derived from the JANAF tables. There is, however, some uncertainty since JANAF‐recommended values for heats of vaporization and partial vapor pressures differ from the results of a detailed analysis that was carried out at the Lawrence Livermore National Laboratory (LLNL). We find that the LLNL model yields carbon‐vaporization enthalpies that are appreciably lower than the JANAF‐based values. In this light, we examine experimental data generated in the course of a comprehensive investigation of laser‐interaction effects in graphite and conclude that our experiments are indicative of an H_A equal to 31.0±1.6 kJ/g.