Two-step laser excitation and ionization from the 7p 2P3/2 state of potassium

Abstract

New measurements of photoionization cross-sections from the 7p 2P3/2 excited state of potassium near the first ionization threshold are presented using a two-step laser excitation/ionization technique in conjunction with a time-of-flight (TOF) mass spectrometer. The absolute values of photoionization cross-sections have been determined as (3.52 ± 0.52) Mb, (2.21 ± 0.33) Mb, (1.35 ± 0.22) Mb and (0.54 ± 0.08) Mb at four ionizing laser wavelengths; 1064 nm, 643.61 nm, 532 nm and 355 nm respectively whereas the number density has been determined as (1.6 ± 0.31) × 1010 cm−3. The presently measured experimental values of photoionization cross-sections are in good agreement with the literature experimental and theoretical values.