A nonresonant multiphoton ionization method has been applied for pressure measurement in ultrahigh vacuum. Second harmonics of a commercial picosecond YAG laser was used for ionization of gases in order to reduce noise caused by scattered laser light. Saturation of ionization was observed for H2, CO and CO2 gases at incident laser power density of about 1013 Wƃcm-2.
ASJC Scopus subject areas
- Physics and Astronomy(all)