Molecular ionization of chloromethane in strong fields: nearest neighbor gateway to highly charged ions

• Published in: Journal of physics. B, Atomic, molecular, and optical physics Vol. 51; no. 16; pp. 165601 - 165610
• Main Authors: Grugan, P D, Ekanayake, N, White, S, Luo, S Y, Ruan, P, Walker, B C
• Format: Journal Article
• Language: English
• Published: IOP Publishing 24.07.2018
• Subjects: chloromethane; highly charged ions; molecular ionization; strong field; ultrafast laser
• ISSN: 0953-4075; 1361-6455
• DOI: 10.1088/1361-6455/aacf82

The strong and ultrastrong field-molecule interaction is a complex, many-body process involving multiple ionization processes. We present ion yields and molecular fragment energies for the ionization of chloromethane (CH3Cl) in a laser field with intensities spanning from 1014 to 1017 W cm−2. As the laser intensity increases, ionization of CH3Cl is observed to pass from molecular tunneling, to enhanced ionization (EI), to an atomic-like response. The energy spectra of the ions show no dependence on the intensity and has its source in dissociative molecular ionization. A classical model of an aligned C-Cl ion is used to model the interaction. Following an initial molecular ionization process, our results show EI is a driving influence in the formation of low charge states until ionization become atomic-like and involves tightly bound ion states whose ionization is unaffected by nearest neighbor ions of similar ion charge.