Photoelectron and photoion imaging spectroscopy of metal-doped nanodroplets and rare gas clusters

• Applicant: Professor Dr. Marcel Mudrich
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2012 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 214242089

• Final Report Year: 2017

Final Report Abstract

The most relevant projected experiments aiming at characterizing the excited states dynamics of metal atoms attached to He nanodroplets using nanosecond and femtosecond spectroscopy were successfully carried out and the results are published in a series of papers. Various aspects of the photodynamics of metal atom doped He nanodroplets were systematically studied using Rb and Cs, and Rb2 as samples. The approach to combine VMI detection of photoelectrons and ions with nanosecond as well as femtosecond photoionization was successfully realized. It has proven to reveal a multitude of fine details of dopant-droplet interactions with high spectral and time resolution. Thus, the pseudo-diatomic dissociation dynamics of Rb from the surface of He droplets when excited into various electronic states was traced in real time. An important dynamical effect - the fall-back of the photoionized dopant atom in the course of desorption - was unambiguously identified and quantitatively analyzed by comparing with high-level quantum fluid dynamics simulations done by Manuel Barranco and coworkers in Barcelona. RbHe exciplex formation and desorption thereof, spin and electronic relaxations induced by the He droplets were characterized in detail and are still being analyzed.

Publications

• “Photoionization and imaging spectroscopy of rubidium atoms attached to helium nanodroplets”, Physical Chemistry Chemical Physics 14, 3843 (2012)
  L. Fechner, B. Gruener, A. Sieg, C. Callegari, F. Ancilotto, F. Stienkemeier, M. Mudrich
  
• “Desorption Dynamcs of Heavy Alkali Metal Atoms (Rb, Cs) Off the Surface of Helium Nanodroplets”, Journal of Physical Chemistry A 118, 6604 (2014)
  J. v. Vangerow J, Sieg A, Stienkemeier F, Mudrich M, Leal A, Mateo D, Hernando A, Barranco M, Pi M
  
• “Photoionization of Pure and Doped Helium Nanodroplets”, International Reviews in Physical Chemistry 33, 301 (2014)
  M. Mudrich and F. Stienkemeier
  
• “Dynamics of solvation and desolvation of rubidium attached to He nanodroplets”, Journal of Chemical Physics 143, 034302 (2015)
  J. von Vangerow, O. John, F. Stienkemeier, M. Mudrich
  
• “Desorption Dynamics of Rb2 Molecules Off the Surface of Helium Nanodroplets“, Journal of Physical Chemistry A 120, 7641 (2016)
  A. Sieg, J. von Vangero B. w, F. Stienkemeier, O. Dulieu, and M. Mudrich
  
• “Imaging Excited State Dynamics of Doped He Nanodroplets in Real-Time”, Journal of Physical Chemistry Letters 8, 307−312 (2017)
  J. von Vangerow, F. Coppens, A. Leal, M. Pi, M. Barranco, N. Halberstadt, F. Stienkemeier, and M. Mudrich