January 25, 2023 Dataset Open Access

PESA Measurements of Aerosol Samples Collected in an Urban Area in Amman, Jordan (Metadata RADIATE TA Proposal 21002363-ST)

Sa'adeh, Hanan; Chiari, Massimo

Proposal title "PESA Measurements of Aerosol Samples Collected in an Urban Area in Amman, Jordan". Measurements carried out at the in-vacuum IBA chamber set-up of the INFN LABEC accelerator laboratory, from 18 till 22 July 2022 and from 23 till 24 January 2023. Hands-off mode.

Particle elastic scattering analysis (PESA) measurements were carried out on a total of 240 fine (PM2.5) and coarse (PM10) particulate matter samples collected on Teflon filters on a sequential basis (24 hr-sampling, 2-3 times a week) in Amman, Jordan to determine hydrogen concentrations (useful marker for organic compounds). Over the last few years, the University of Jordan, Amman, has been interested in studying the characteristic features of atmospheric aerosols in the framework of the International Atomic Energy Agency (IAEA) regional technical cooperation projects (IAEA TC projects RAS0072, RAS0076, and RAS0078) for ARASIA member states (Arab states in Asia who are members of the IAEA).
In-vacuum PESA measurements have been performed with protons of 3.6 MeV energy, with a beam current of 10-15 nA and lasting 150 s. The hydrogen content has been obtained from the scattered/recoiled protons detected by a Silicon pin diode placed at a 30° scattering angle (forward scattering). Apart from the aerosol samples, a thin Upilex foil, containing known amounts of hydrogen, has been repeatedly analysed as well; it is used as standard for the quantitative analysis and to check reproducibility and repeatability.

From the total hydrogen content as obtained by PESA it is possible to infer the H contained in organic compounds, H_org (to be used for instance in source apportionment studies as proxy of organic matter) by subtracting to the total H measured by PESA, H_PESA, the additional hydrogen from ammonium (NH₄⁺), assuming that all ammonium ions are balanced by sulfate ions (SO₄^2-), that is 8 H for each S in the molecule, with S obtained by PIXE, S_PIXE: H_org = H_PESA - 0.25 · S_PIXE.