A novel and efficient excitation- and ionization-scheme for laser resonance ionization of mercury

摘要

A novel, efficient scheme for mercury atomic resonance ionization is proposed and experimentally studied with wavelengths #lambda#_1 = 254 nm, #lambda#_2 = 313 nm and #lambda#_3 = 626 nm. The cross-sections of mercury photoionization from different excited states were estimated using a new imaging method of resonance ionization signal measurement. Almost 100% efficiency of Hg resonance ionization was achieved using the first harmonic of a dye laser at 626 nm to ionize mercury atoms excited into the 6~3D_2 state. The photoionization cross-section from this state was found to be 1.5 * 10~(-18) cm~2. Suppression of the ionization signal by coherent effects (electromagnetically-induced transparency) and the efficiency of resonance ionization were also studied.