α-particle spectrometer based on xenon gas ionization chamber using coplanar electrodes

A parallel plate gas ionization chamber with coplanar electrodes was designed and developed to be used as an α-particle spectrometer measuring low level α-emission rates in environmental samples from the vicinity of nuclear power plants. The chamber was filled with a 3 atm gas mixture of Xe + 0.7% CH4. Its performance was investigated using a mixed α-particle source (237Np, 241Am, and 244Cm). An excellent energy resolution of 59 keV (1.0%) in fwhm for 5.81 MeV 244Cm α-particles was obtained, which is enough to identify major sources of alpha radioisotopes (238U, 235U, 237Np, 239Pu, 238Pu, 241Am, 244Cm) to be found near nuclear power plants.