Analysis of stable-isotope tracers by proton scattering

The availability of proton elastic scattering for the analysis method of stable isotopes was investigated with proton beams of a tandem accelerator. Attention has been paid to target backing, selection of incident energy and detection system for scattered protons for obtaining sharp peaks of elastic scattering protons from stable isotopes. The best selection for the measurement of 15N and/or 18O was surveyed as a preliminary test. A linear relationship between 15N or 18O-concentration and their proton yield was confirmed. This method was applicable to a sample containing 15N and 18O in a concentration as low as their natural abundances. As an application of this method, examples of spectra for 15N and 18O in biological samples are also shown. (orig.)