21-EPN-FT1-023: Diagnostics of electron collisions with small organic molecules present in the atmospheres of small bodies and planets
June 3, 2023

21-EPN-FT1-023: Diagnostics of electron collisions with small organic molecules present in the atmospheres of small bodies and planets

Visit by Bartosz Michalczuk, Siedlce University (Poland), to TA2 Facility 13 – Electron Induced Fluorescence Laboratory (Slovakia).
Dates of visit: 21 – 30 November 2022

Report Summary:

The main objective of the project was to study electron impact processes of small organic compounds, using acetone as the first target.

  • Record and analyse emission spectra of acetone induced by electron impact at several different energies in the range 10 – 100 eV.
  • Determine emission cross sections corresponding to selected most intensive transitions in range of impact energies (from the thresholds of selected process to 100 eV).
  • Identify neutral products of electron impact fragmentation of acetone.
  • Determine reaction kinetics parameters such as threshold energies for selected electron impact excitation reactions of acetone.

During the first half of the visit, we measured electron-impact spectra of acetone at multiple electron energies and generated partial spectral electron energy map which provides the spectral information at various electron energies and thus the efficiency curves (relative emission cross-section curves).
During the second half of the visit, the measured data was partially analysed. The emission band in the range of 415 – 445 nm corresponds to the radiation of CH (A2Δ–X2Π) (ν,ν) fragment. Less intensive radiation of CH (B2Σ−–X2Π) (0,0) fragment was identified within 386 – 402 nm. Several emission lines of hydrogen’s Balmer series Hγ – Hη were detected throughout the spectrum as well. Individual rotational transitions from P, Q, R branches of both CH fragments were identified according to LIFBASE 2.1.1 spectroscopy tool, which is software to chart the spectroscopy of diatomic molecules. The rotational temperature of the LIFBASE spectrum was set to ~ 5000 K.

Read the full scientific report, with kind permission by Steve Bromley.