Chemical analysis with a low energy particle accelerator

The low energy particle accelerator at Brooklyn College is being applied to chemical analysis by studies of: charged particle induced nuclear reaction, proton induced X-ray emission, and inelastic neutron scattering. A great advantage in sensitivity and resolution (i.e., freedom from interferences) is attained when it is possible to observe the nuclear reactions per se. The prompt products may be gamma-rays, neutrons, and/or emergent charged particles such as protons, alphas, and even heavier ions. Chemical analysis by direct observation of the prompt phenomenon offers these advantages: the analysis does not depend upon the half life of the product nuclide; the sensitivity is increased by as much as several orders of magnitude; there is a greater selectivity due to the characteristic energy requirements; and the prompt methods lend themselves more readily for absolute rather than relative determinations. Fluorine-containing gaseous compounds in the atmosphere and fluorine in airborne particulates will be determined by detection of the prompt gamma-rays and/or alpha particles emitted in the reaction 19F(p, α)16O. The PIXE technique is being applied to analysis of a variety of environmental samples, and activation by inelastic neutron scattering is being investigated for elements which are not amenable to thermal neutron activation. (T.G.)