The advent of the trap based beam has made possible the highest resolution cross sectionmeasurements of positrons interacting with atoms and molecules to date. The strong magneticfield needed for the trap required new methods of making cross section measurements in such afield. We first describe absolute, integrated inelastic cross section measurements. However, thesetechniques can also be applied to electron scattering and in fact provide some advantages forintegrated electron-impact cross section measurements. Additionally the ability to do both in thesame apparatus minimizes systematic effects in comparative measurements. This paper reports onthe results on the first of these measurements, vibrational excitation in CF_4.
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