A nuclear reaction product mass spectrometer

The design of a mass spectrometer capable of determining directly the mass of nuclear reaction products, independent of the velocity with which they leave the target, is discussed. The spectrometer employs only electric and magnetic dipoles and magnetic quadrupoles to focus all particles of a given mass to the same point on the focal plane. The usable solid angle is a function of the mass resolution and can be as large as 5 msr. The magnification of the device is 3.3 which means that the angular convergence of particle paths at the focal plane is very small with the consequence that the focal plane may, without significant loss of resolution be regarded as straight and perpendicular to the particle path in all practical cases. The mass dispersion of the spectrometer is ∼13 mm/% and the resolving power (a function of solid angle) can be as large as m/Δm = 400.