Ion cyclotron radiofrequency heating experiments were performed with a 3He minority ion species in a 4He majority plasma in the Princeton Large Torus. The energetic 3He ion 'tail' was measured directly with a charge exchange neutral analyser for the first time. Comparisons with bounce averaged quasi-linear calculations suggest a modestly peaked radiofrequency power deposition profile. The double charge exchange process 3He++ + 4He0 → 3He0 + 4He++ demonstrated in these measurements may be useful as part of an alpha particle diagnostic in a fusion reactor experiment.