Charge stripping and delayed autoionization in doubly charged ions of the noble gases

Abstract

Doubly charged ions of each of the rare gases neon, argon, krypton and xenon, formed by electron impact and accelerated through 6 kV in a double-focusing mass spectrometer, are ionized to the corresponding triply charged ions via processes of at least two general kinds. The first proceeds under collision-free conditions, and can be attributed to delayed (microsecond) autoionization. An alternative explanation involving transitions from high Rydberg states, induced by the 350 K black-body radiation within the analyser vacuum housing, cannot be entirely ruled out. Other ionization processes require a collision with a molecule of collision gas, and result in a measurable loss of translational energy. In this paper the knowledge of analogous processes of the corresponding singly charged ions is reviewed, the general features of the translational energy spectra are established, and effort is devoted to the characterization of the collision-free process. The collision-induced processes have been interpreted in terms of known metastable states of the doubly charged ions.

Comparison and Search for CH53+ and CH64+ and Their Isoelectronic Boron Analogues BH52+ and BH63+ 1

“…The methane cation and dication are of great significance and have been the subject of many experimental and theoretical studies . The methane cation CH 4 +• is the parent ion in mass spectrometry, and the methane dication CH 4 2+ has been observed in the gas phase . The planar C 2 v symmetrical structure 1 is preferred for CH 4 2+ as shown4a by Wong and Radom.…”