TY - JOUR
T1 - Laser-induced Coulomb explosion of heteronuclear alkali-metal dimers on helium nanodroplets
AU - Albrechtsen, Simon H.
AU - Christensen, Jeppe K.
AU - Tanyag, Rico Mayro P.
AU - Kristensen, Henrik H.
AU - Stapelfeldt, Henrik
PY - 2024/4
Y1 - 2024/4
N2 - A sample mixture of alkali-metal homonuclear dimers, Ak2 and Ak2′, and heteronuclear dimers, AkAk′, residing on the surface of helium nanodroplets are Coulomb exploded into pairs of atomic alkali-metal cations, (Ak+,Ak+), (Ak′+,Ak′+), and (Ak+,Ak′+), following double ionization induced by an intense 50-fs laser pulse. The measured kinetic-energy distribution P(Ekin) of both the Ak+ and Ak′+ fragment ions contains overlapping peaks due to contributions from Coulomb explosion of the homonuclear and heteronuclear dimers. From P(Ekin), we determine the distribution of internuclear distances P(R) via the Coulomb-explosion imaging principle. Using coincident filtering based on momentum division between the two fragment ions, we demonstrate that the individual P(Ekin) distributions pertaining to ions from either hetero-or homonuclear dimers can be retrieved. This filtering method works through the concurrent detection of two-dimensional velocity images of the Ak+ and the Ak′+ ions implemented through the combination of a velocity-map-imaging spectrometer and a TPX3CAM detector. The key finding is that P(R) can be measured for any specific dimer in the unavoidably mixed sample of hetero-and homonuclear alkali-metal dimers. We report results for LiK and NaK, which were previously unmeasurable by the Coulomb-explosion technique. Our method should also work for other heteronuclear dimers and for differentiating between different isotopologues of any of the dimers.
AB - A sample mixture of alkali-metal homonuclear dimers, Ak2 and Ak2′, and heteronuclear dimers, AkAk′, residing on the surface of helium nanodroplets are Coulomb exploded into pairs of atomic alkali-metal cations, (Ak+,Ak+), (Ak′+,Ak′+), and (Ak+,Ak′+), following double ionization induced by an intense 50-fs laser pulse. The measured kinetic-energy distribution P(Ekin) of both the Ak+ and Ak′+ fragment ions contains overlapping peaks due to contributions from Coulomb explosion of the homonuclear and heteronuclear dimers. From P(Ekin), we determine the distribution of internuclear distances P(R) via the Coulomb-explosion imaging principle. Using coincident filtering based on momentum division between the two fragment ions, we demonstrate that the individual P(Ekin) distributions pertaining to ions from either hetero-or homonuclear dimers can be retrieved. This filtering method works through the concurrent detection of two-dimensional velocity images of the Ak+ and the Ak′+ ions implemented through the combination of a velocity-map-imaging spectrometer and a TPX3CAM detector. The key finding is that P(R) can be measured for any specific dimer in the unavoidably mixed sample of hetero-and homonuclear alkali-metal dimers. We report results for LiK and NaK, which were previously unmeasurable by the Coulomb-explosion technique. Our method should also work for other heteronuclear dimers and for differentiating between different isotopologues of any of the dimers.
UR - http://www.scopus.com/inward/record.url?scp=85190889348&partnerID=8YFLogxK
U2 - 10.1103/PhysRevA.109.043112
DO - 10.1103/PhysRevA.109.043112
M3 - Journal article
AN - SCOPUS:85190889348
SN - 2469-9926
VL - 109
JO - Physical Review A
JF - Physical Review A
IS - 4
M1 - 043112
ER -