Observation of a four-electron Auger process in near-K-edge photoionization of singly charged carbon ions

Phys Rev Lett. 2015 Jan 9;114(1):013002. doi: 10.1103/PhysRevLett.114.013002. Epub 2015 Jan 7.

Abstract

Single, double, and triple ionization of C(1+) ions by single photons is investigated in the energy range of 286-326 eV, i.e., in the range from the lowest-energy K-vacancy resonances to well beyond the K-shell ionization threshold. Clear signatures of C(1+)(1s2s(2)2p(2) (2)D,(2)P) resonances are found in the triple-ionization channel. The only possible mechanism producing C(4+)(1s(2)) via these resonances is direct triple-Auger decay, i.e., a four-electron process with simultaneous emission of three electrons.