Radioactivity and Air Dose Rate
（2019）
ＱHow can the surface properties of minerals to which radioactive Cs is adhered be analyzed?
ＡThe composition, concentration, and chemical bonds on the surface of minerals can be measured using an X-ray photoelectron spectrometer (XPS) or Auger electron spectrometer (AES).
Fig.1 Principles of XPS
（Source : JEOL website）
An XPS irradiates X-rays onto a sample to measure the kinetic-energy distribution of electrons ejected from the surface.
Fig.2 Principles of AES
（Source：MST website）
An AES irradiates electron beams on a sample to measure the kinetic-energy distribution of Auger electrons (secondary electrons) elected from the surface.
Fig.3 Example analysis Depth-wise changes in element concentration on the surface of mineral samples
- We examined the elemental composition and surface concentrations of mineral samples containing radioactive Cs that were obtained around 1F (Y-axis) and the depth-wise changes in the element concentration from the surface (X-axis).
- Carbon (organic matter) was found to exist in shallow portions close to the surface of minerals, with this content decreased in deeper portions. We also found that minerals, including iron and magnesium, exist around the surface.