A prism mass-spectrometer for isotope analysis of hydrogen–helium mixtures

An original scheme of a special magnetic mass-spectrometer for isotope measurements in a mass range of hydrogen–helium mixtures and their main impurities is proposed. The ion optics system contains a two-dimensional magnetic prism supplemented with two identical cylindrical electrostatic capacitors matched so that the system operates in the regime of complete triple focusing of the ion beam in two orthogonal directions and with respect to ion energies. The system ensures high dispersion and allows the mass resolution (no less than 3500) required for analysis at high brightness and a central ion trajectory length on the order of 1 m.