Measurements of photoionization cross sections from the 4p, 5d and 7s excited states of potassium

✍ Scribed by Nasir Amin; S. Mahmood; S.U. Haq; M.A. Kalyar; M. Rafiq; M.A. Baig

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 221 KB
• Volume: 109
• Category: Article
• ISSN: 0022-4073
• DOI: 10.1016/j.jqsrt.2007.09.008

✦ Synopsis

New measurements of the photoionization cross sections from the 4p 2 P 1/2,3/2 , 5d 2 D 5/2,3/2 and 7s 2 S 1/2 excited states of potassium are presented. The cross sections have been measured by two-step excitation and ionization using a Nd:YAG laser in conjunction with a thermionic diode ion detector. By applying the saturation technique, the absolute values of the cross sections from the 4p 2 P 3/2 and 4p 2 P 1/2 states at 355 nm are determined as 7.271.1 and 5.670.8 Mb, respectively. The photoionization cross section from the 5d 2 D 5/2,3/2 excited state has been measured using two excitation paths, two-step excitation and two-photon excitation from the ground state. The measured values of the cross sections from the 5d 2 D 5/2 state by two-photon excitation from the ground state is 28.974.3 Mb, whereas in the two-step excitation, the cross section from the 5d 2 D 3/2 state via the 4p 2 P 1/2 state and from the 5d 2 D 5/2,3/2 states via the 4p 2 P 3/2 state are determined as 25.173.8 and 30.274.5 Mb, respectively. Besides, we have measured the photoionization cross sections from the 7s 2 S 1/2 excited state using the two-photon excitation from the ground state as 0.6170.09 Mb.