Laser-induced Electron-Transfer in the Dissociative Multiple Ionization of Argon Dimers

Dissociative electron attachment to pulsed supersonic O$_2$ jet : Violation of $Σ^{+} \rightleftharpoons Σ^{-}$ selection rule and dependence on carrier gas proportion

The formation of $O^{-}$ and $O_{2}^{-}$ ions via dissociative electron attachment to a pulsed supersonic jet of $O_{2}$ molecules containing weakly bound small van der Waals clusters seeded in a beam of argon is reported. The energy dependence of the $O^{-}$ and $O_{2}^{-}$ yield exhibits three peaks near 7, 11 and 16 eV incident electron energies. The 7 eV peak arises from the $^{2}Π_{u}$ state of $O_{2}^{-}$ whereas, the 11 and 16 eV peaks are ascribed to two distinct resonance states:$ ^{2}Σ_{g}^{+} $ and $^{2}Σ_{u}^{+}$ states of $O_{2}^{-}$, respectively, via a violation of the $Σ^{+} \r…

Ion impact induced Interatomic Coulombic Decay in neon and argon dimers

We investigate the contribution of Interatomic Coulombic Decay induced by ion impact in neon and argon dimers (Ne$_2$ and Ar$_2$) to the production of low energy electrons. Our experiments cover a broad range of perturbation strengths and reaction channels. We use 11.37 MeV/u S$^{14+}$, 0.125 MeV/u He$^{1+}$, 0.1625 MeV/u He$^{1+}$ and 0.150 MeV/u He$^{2+}$ as projectiles and study ionization, single and double electron transfer to the projectile as well as projectile electron loss processes. The application of a COLTRIMS reaction microscope enables us to retrieve the three-dimensional momentu…

Observation of (N2)2 dimers in free nitrogen and argon-nitrogen clusters

Supersonic-jet luminescence spectroscopy was applied to study vibronic transitions in icosahedral N2 and Ar-N2 clusters having from 100 to 400 particles per cluster. In the case of mixed Ar-N2 clusters, the w->X transitions were observed to occur in single N2 molecules in an Ar environment, that is very much in the same way as in Ar-N2 bulk samples. In N2 clusters, however, a band series was detected which was never observed earlier. In the spectra of Ar-N2 clusters, this new series coexisted with the 'bulk' w->X transitions. Our analysis demonstrated that the series should be assigned to emis…

原子间库仑衰变起始于氦离子和氩双聚体碰撞中的电子移除和激发过程

Interatomic Coulombic decay initiated by electron removal and excitation processes in helium ion and argon dimer collisions

研究了氦离子和氩双聚体碰撞中促进原子间库仑衰变的电子移除和激发通道，通过统计技术分析电子激发路径，发现3d激发态是主要衰变通道，且随着碰撞能量变化，静态和动态势模型存在差异。

Swirling the weakly bound helium dimer from inside

Controlling the interactions between atoms with external fields opened up new branches in physics ranging from strongly correlated atomic systems to ideal Bose and Fermi gases and Efimov physics. Such control usually prepares samples that are stationary or evolve adiabatically in time. On the other hand, in molecular physics external ultrashort laser fields are employed to create anisotropic potentials that launch ultrafast rotational wave packets and align molecules in free space. Here we combine these two regimes of ultrafast times and low energies. We apply a short laser pulse to the helium…

Dissociation energies of AgRG (RG = Ar, Kr, Xe) and AgO molecules from velocity map imaging studies

The near ultraviolet photodissociation dynamics of silver atom rare gas dimers have been studied by velocity map imaging. AgRG (RG = Ar, Kr, Xe) species generated by laser ablation are excited in the region of the C <- X continuum leading to direct, near threshold dissociation generating Ag* (2P3/2) + RG (1S0) products. Images recorded at excitation wavelengths throughout the C <- X continuum, coupled with known atomic energy levels, permit determination of the ground X (2SIGMA+) state dissociation energies of 85.9 +/- 23.4 cm-1 (AgAr), 149.3 +/- 22.4 cm-1 (AgKr) and 256.3 +/- 16.0 cm-1 (AgXe)…