Intense-Field Ionization of Monoaromatic Hydrocarbons using Radiation Pulses of Ultrashort Duration: Monohalobenzenes and Azabenzenes

28th International Conference on Photonic, Electronic and Atomic Collisions

Scarborough, T.^1 ; Strohaber, J.^2 ; Foote, D.^3 ; McAcy, C.^4 ; Uiterwaal, C.J.^4

California Institute of Technology, Pasadena

CA

91125, United States^1

Texas A and M University, College Station

TX

77843, United States^2

University of Maryland, College Park

MD

20742, United States^3

Department Physics and Astronomy, Jorgensen Hall, U. Nebraska-Lincoln, 855 N. 16th St., Lincoln

NE

68588, United States^4

关键词: Focal intensity;    Heavy atom effects;    Intense field ionization;    Inter-system crossings;    Monoaromatic hydrocarbon;    Radiation pulse;    Resonance enhanced;    Triplet state;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/488/3/032033/pdf
DOI  :  10.1088/1742-6596/488/3/032033

来源: IOP

【 摘 要 】

Using 50-fs, 800-nm pulses, we study the intense-field ionization and fragmentation of the monohalobenzenes C6H5-X (X=F, Cl, Br, I) and of the heterocyclics azabenzene C5H5N (pyridine) and the three diazabenzenes C4H4N2(pyridazine, pyrimidine, and pyrazine). Avoiding focal intensity averaging we find indications of resonance-enhanced MPI. In the monohalobenzenes the propensity for fragmentation increases for increasing Z: fluorobenzene yields predominantly C6H5Fn+, while iodobenzene yields atomic ions with charges up to I8+. We ascribe this to the heavy-atom effect: the large charge of the heavy halogens' nuclei induces ultrafast intersystem crossing to dissociative triplet states.