Energy calibration of a plastic scintillator beta telescope

A ΔE-E plastic scintillator β telescope had been built, and calibrated by using a group of β- and β+ emitters and a 207Bi source. Their end-point energies were determined via two different methods, i.e. weighted linear least-square fit to the Fermi-Kurie plots of the data after correcting for the finite energy resolution of the E scintillator and direct linear least-square fit to the square root of the raw data. It is shown that the latter can estimate the end-point energy rapidly, while the former can be used to determine the end-point energy with uncertainty about 35 keV for energy ranging 0.7 to 6.1 MeV