Unrecognized backscattering in low energy beta spectroscopy

We present studies on electron backscattering from the surface of plastic scintillator beta detectors. By using a setup of two detectors coaxial with a strong external magnetic field-one detector serving as primary detector, the other as veto-detector to detect backscattering-we investigate amount and spectrum of unrecognized backscattering. These are events where only one detector recorded a trigger signal. The implications are important for low energy particle physics experiments