Development of an in-air high-resolution PIXE system

Abstract A compact wavelength-dispersive crystal spectrometer system has been developed for high-resolution PIXE experiments in atmospheric air. A sample target placed in the air is irradiated with an external beam of protons. X-rays are diffracted with a flat analyzing crystal and detected with a position-sensitive proportional counter. Nearly all of the X-ray path from the target to counter is enveloped with a polyethylene bag filled with helium gas. The lowest X-ray energy detectable with this system is 0.9 keV and the angular resolution is 0.1° in the diffracting angle.