A transmission time-of-flight system for particle identification at a recoil mass separator at low energies

A new time-of-flight (TOF) system has been installed at the recoil mass separator DRAGON at the radioactive beam facility TRIUMF-ISAC in Vancouver, Canada. The addition of a velocity measurement to the existing energy measurement provides an effective separation of heavy ion reaction particles from remaining beam particles reaching the end detector, especially at low beam energies of interest to nuclear astrophysics research. The TOF detector system is based on two electrostatic mirrors equipped with thin carbon foils as a secondary electron emitter, and micro-channel plates for a fast timing signal. The system has been commissioned with stable 23Na, 24Mg and 27Al beams in the energy range from 200 to 800AkeV.