title: Ring focus in a thin magnetic-lens beta-ray spectrometer.
authors.forename: J M
authors.initials: JM
authors.lastname: KELLER
authors.forename: E
authors.initials: E
authors.lastname: KOENIGSBERG
authors.forename: A
authors.initials: A
authors.lastname: PASKIN
mesh_terms: D001610:Beta Particles; D007909:Lenses; D060328:Magnetic Phenomena; D019736:Prostheses and Implants; D013057:Spectrum Analysis / Q000295:instrumentation*