027 -- Time-of-Flight Spectrometer Experimental Campaign

A Time-of-Flight Spectrometer has been developed at SUNY Geneseo utilizing low energy ions, usually 50 keV alpha particles, for use in target surface analysis. Predicting the energy loss of these ions after elastically scattering off the target as well as traveling through a carbon foil is imperative to the function of the spectrometer. Several computer programs such as a Two-Body-Kinematics-Calculator and SRIM (Stopping Ranges of Ions in Matter) are used to calculate this predicted energy loss. An experimental campaign was conducted using a Tantalum target with 10 different path lengths to measure the energy loss of the alpha particles and determine the actual thickness of the carbon foil. Previous energy loss calculations had neglected the transit time for electrons emitted from the carbon foil and detected by the channeltron electron multiplier that serves as the start detector. A new calculation takes this into account, improving the consistency of the calculations. With this modification, the predicted final energy of the alpha particles agrees with the measured value by less than 0.018 keV.