Mass spectrometric analysis of carbon species generated by laser evaporation

✍ Scribed by P.D. Zavitsanos

• Book ID: 102993328
• Publisher: Elsevier Science
• Year: 1968
• Tongue: English
• Weight: 517 KB
• Volume: 6
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(68)90017-1

✦ Synopsis

Using a ruby laser as an energy source, vaporization rates were measured for several types of graphite in the energy range 0.85-12.6 J and power density lo"-106 W/cma. Avaporization rate, m/E = (1.7 i 0.3) x loss g/J, was measured with a corresponding heat of vaporization, AH, = (44 f 9) x 10" J/g, and an average molecular weight for the resulting vapor, M.W. = 18 f 4. Time resolved mass spectra were obtained on the carbon vapor with the time of flight mass spectrometer. Relative concentrations of C&/C, (n = 1, 3, 4. . . 10) were determined and an average molecular weight, M.W. = 22, was calculated. Based on the ratios, C&/C, and C,jC,, a surface temperature of 406~4100°K was estimated.