Atmospheric processes on ice nanoparticles in molecular beams

Abstract

This review summarizes some recent experiments with ice nanoparticles (large water clusters) in molecular beams and outlines their atmospheric relevance: (1) Investigation of mixed water–nitric acid particles by means of the electron ionization and sodium doping combined with photoionization revealed the prominent role of HNO3 molecule as the condensation nuclei. (2) The uptake of atmospheric molecules by water ice nanoparticles has been studied, and the pickup cross sections for some molecules exceed significantly the geometrical sizes of the ice nanoparticles. (3) Photodissociation of hydrogen halides on water ice particles has been shown to proceed via excitation of acidically dissociated ion pair and subsequent biradical generation and H3O dissociation. The photodissociation of CF2Cl2 molecules in clusters is also mentioned. Possible atmospheric consequences of all these results are briefly discussed.

Extensive water cluster fragmentation after low energy electron ionization

“…Large (H 2 O) N clusters withN ≈ 10-10 3 represent laboratory model to mimic 5 important systems and processes, e.g., cloud particle and aerosol nucleation [4,5,6,7,8], chemistry and photochemistry on ice particles in atmosphere [9,10,11,12], processes in radiation chemistry [13], processes in chemistry and biology induced and controlled by solvent [14] etc. In many laboratory studies water clusters are detected by mass spectrometric methods.…”

Proton transfer and isotope-induced reaction in aniline cluster ions

“…The experiment was performed on our cluster beam (CLUB) apparatus. It is a complex molecular beam setup devoted to the investigations of photochemistry and other processes in clusters and nanoparticles in molecular beams . The apparatus has recently been extended with a reflectron time‐of‐flight (RTOF) mass spectrometer allowing for various mass spectrometric studies of clusters using different methods of ionization, e.g.…”

Mass spectrometry of aerosol particle analogues in molecular beam experiments

“…On the other hand, such clusters can be investigated in molecular beams. In these experiments, generation and growth of the clusters can be studied and their structure and composition can be revealed in unprecedented details . In addition, different processes can be induced in these clusters by photons, electrons, ions, and other types of radiation with various energies, in analogy to the atmospheric processes triggered by cosmic radiation.…”