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The improvements made to ultra-thin windows for X-ray detectors in recent years have allowed for the detection of elements as light as lithium. However, their use with particle induced X-ray emission (PIXE) spectroscopy typically requires the addition of an absorber thick enough to prevent backscattered ions from reaching the detector. This also prevents lower energy (< 1 keV) X-rays from reaching the detector. By using a magnetic field to deflect backscattered ions away, the absorber can be eliminated, allowing for the detection of ultra-low energy X-rays. At the Ion Beam Laboratory of the University of North Texas, a prototype PIXE system using a magnetic deflector has been developed to allow for the detection and measurement of X-rays from light elements using a silicon drift X-ray detector with an ultra-thin window. With an average magnetic flux density of 0.88 T along the center, backscattered protons of an energy up to 1.22 MeV were successfully deflected away from the X-ray detector. Light element PIXE was performed with a 1 MeV proton beam on manganese oxide, sodium chloride and a Hibiscus rosa-sinensis leaf. Elements of 5 ≤ Z ≤ 30 were successfully detected. 

PIXE analysis was conducted on p8 fisher brand filter paper samples soaked in elemental standard solutions to determine the minimum detectable levels of Al, Si, P, S, Cl, K, Ca, Cr, Fe, Ni, Cu, and Se. All samples were analyzed with beam parameters of 2 µC incident charge, and beam current of less than 2 nA at 2 MeV beam energy. Minimum detectable levels were obtained by analyzing the x-ray spectrum in the GeoPIXE analysis package, and the data for each element would be averaged over all collected spectra. The minimum detectable level in parts per million was found to be on average 9.59 for Al, 4.6 for Si, 3.23 for P, 2.27 for S, 1.82 for Cl, 1.15 for K, 0.88 for Ca, 0.51 for Cr, 0.07 for Mn, 0.54 for Fe, 1.59 for Ni, 2.0 for Zn, 1.55 for Cu, and 6.5 for Se. Minimal deviation from the averaged values was observed, except in cases where samples contained high concentrations of elements with overlapping X-ray energies.