An upgraded external beam PIXE setup for multielemental analysis of atmospheric aerosol samples

Abstract

The external beam particle-induced X-ray emission (PIXE) setup has been upgraded by introducing a new silicon drift detector with the aim of obtaining better minimum detection limits (MDLs) at the 2 × 1.7 MV Tandetron accelerator of the Beijing Normal University in China. The upgraded external beam PIXE setup is equipped with two silicon drift detectors for PIXE analysis of low and high Z elements. A surface barrier detector for Rutherford backscattering spectrometry monitors beam and helium flow. Two kinds of aerosol filter samples (quartz fiber filters and Teflon filters) were studied. A 200-μm thick Mylar absorber in front of the medium-high energy X-rays detector was adopted, and it got the best MDLs for atmospheric aerosol samples analysis. Multielemental analysis of quartz fiber filter aerosol samples was achieved.For more accurate and better MDLs of low Z elements in PIXE analysis, it is necessary to keep sufficient helium flow behind the thin samples.

Atomic Spectrometry Update – a review of advances in environmental analysis

“…Chinese researchers upgraded 48 their PIXE capability at the accelerator facility at the Beijing Normal University in order to improve the analysis of aerosol samples collected on either quartz or Teflon filters. Replacing the SDD with one with a higher sustainable counting rate minimised the potential for Si-K alpha count rate saturation when analysing quartz filters.…”

“…He et al237 reported stable Ca isotopic compositions for 10 geological RMs relative to NIST SRM 915a (calcium carbonate) and its replacement NIST SRM 915b, ranging in composition from peridotite to sandstone. By applying a43 Ca-48 Ca double-spike technique, δ 44 Ca/42 Ca and ε 40 Ca/44 Ca were measured simultaneously by TIMS with a precision of ±0.03‰ and ±1.0, respectively (n≥8). The comprehensive compilation of Ca isotopic compositions provided for these geological RMs should enhance future interlaboratory comparisons of Ca isotopic measurements.…”

Light-element sensitive in-air millibeam PIXE setup for fast measurement of atmospheric aerosol samples

“…The tight geometry and the atmospheric environment do not allow the use of best practices which work well in vacuum. At the ion beam facilities around the world, several different methods have been implemented for monitoring the beam dose including simultaneous RBS measurements 16,17 monitoring the exit window 18 or applying electrostatic deection systems, 19 beam prole monitors 20 and beam choppers. 21 Because of these reasons we seized the opportunity to create an external millibeam PIXE setup which fulls the requirements of advanced atmospheric aerosol and heritage science research.…”