Mass Spectrometric Study of the Laser-Produced Carbon Vapor Up to 4500 K

The mass spectrometric measurements of the molecular composition in a carbon vapor produced with the laser-induced sublimation of pyrolitic graphite have been carried out up to 4500 K – the temperature in a close vicinity to the triple point of carbon. The measurements of the relative partial pressures of C 1 -C 5 molecules up to the maximum attended temperature did not show any peculiar behavior, which can be attributed to any kind of the phase transition (e.g. melting, etc ) while staying in a good accordance with the most theoretical predictions. The well-known problem of a significant difference of the evaporation coefficients of carbon molecules from unity has been largely treated by a comparative analysis of the evaporation products of two planes of pyrolitic graphite. The technical means allowed for mass spectrometric study of the carbon sublimation up to extreme temperatures are presented in detail