Publications de Junwen Zou | EPFL Graph Search

Ne*(3P2,0) + CO chemi-ionization reactions: Atomic alignment and molecular orientation effects

The present study exploits the recent formulation of the optical potential that provided an internally consistent representation of the interaction between Ne*(3P2,0) + CO reagents and Ne + CO+(X2Σ, A2Π) products. The coupling between neutral entrance and ...

2025

The optical potential for Ne*(3P2,0) + CO chemi-ionization reactions: Nature of the intermolecular forces and selective formation of CO+ in ground (2Σ) and excited (2Π) electronic states

Andreas Osterwalder, Junwen Zou

Ionization processes, promoted by the collisions of CO molecule with noble gas atoms electronically excited in a metastable state, as Ne*, are known as chemi-ionization (CHEMI) reactions. CHEMI reactions of CO have been experimentally investigated in vario ...

2025

Alignment of ND3 molecules in dc-electric fields

Andreas Osterwalder, Viet Le Duc, Junwen Zou

The control of movement and orientation of gas-phase molecules has become the focus of many research areas in molecular physics. Here, ND3 molecules are polarized in a segmented, curved electrostatic guide and adiabatically aligned inside a rotatable mass ...

Aip Publishing2024

Study of He/Ne+Ar, Kr, N2, H2, D2 Chemi-Ionization Reactions by Electron Velocity-Map Imaging

Andreas Osterwalder, Sean Dennis Steven Gordon, Junwen Zou, Silvia Tanteri

The chemi-ionization of Ar, Kr, N2, H2, and D2 by Ne(3P2) and of Ar, Kr, and N2 by He(3S1) was studied by electron velocity map imaging (e-VMI) in a crossed molecular beam experiment. A curved magnetic hexapole was used to state-select the metastable speci ...

2021

Low-energy stereodynamics of ion-forming reactions

Junwen Zou

In this thesis, an experimental study of low-temperature stereodynamics in the reactive scattering of Ne(3P2) + X collisions (X = Ar, Kr, Xe, CO and N2) is presented. The steric effect of Ne(3P2) in these reactions is observed experimentally using a contro ...

EPFL2021

Investigation of the low-energy stereodynamics in the Ne(3P2) + N2, CO reactions

Andreas Osterwalder, Junwen Zou

We report on an experimental investigation of the low-energy stereodynamics of the energy transfer reactions Ne(3P2) + X, producing Ne(1S) + X+ and [Ne–X]+ (X = N2 or CO). Collision energies in the range 0.2 K–700 K are obtained by using the merged beam te ...

2020

Sub-Kelvin stereodynamics of the Ne(3P2)+N2 reaction

Andreas Osterwalder, Sean Dennis Steven Gordon, Junwen Zou

We present an experimental study of the low-energy stereodynamics of the Ne(3P2)+N2 reaction. Supersonic expansions of the two reactants are superposed in a merged beam experiment, where individual velocity control of the two beams allows us to reach avera ...

AMER PHYSICAL SOC2019

Quantum-state-controlled channel branching in cold Ne(3P2)+Ar chemi-ionization

Andreas Osterwalder, Sean Dennis Steven Gordon, Junwen Zou, Silvia Tanteri

A prerequisite to gain a complete understanding of the most basic aspects of chemical reactions is the ability to perform experiments with complete control over the reactant degrees of freedom. By controlling these, details of a reaction mechanism can be i ...

2018

Stereodynamics of Ne(3P2) reacting with Ar, Kr, Xe, and N2

Andreas Osterwalder, Junwen Zou, Sean Dennis Steven Gordon, Silvia Tanteri

Stereodynamics experiments of Ne(3P2) reacting with Ar, Kr, Xe, and N2 leading to Penning and associative ionization have been performed in a crossed molecular beam apparatus. A curved magnetic hexapole was used to state-select and polarize Ne(3P2) atoms w ...

2018

Energy dependent stereodynamics of the Ne(3P2)+Ar reaction

Andreas Osterwalder, Justinas Jankunas, Sean Dennis Steven Gordon, Junwen Zou, Silvia Tanteri

The stereodynamics of the Ne(3P2)+Ar Penning and Associative ionization reactions have been studied using a crossed molecular beam apparatus. The experiment uses a curved magnetic hexapole to polarise the Ne(3P2) which is then oriented with a shaped magnet ...

American Physical Society2017