Temperature and dimension of nuclear tracks

From secondary ion mass and energy spectroscopy we can obtain information on the target properties and on track formation mechanisms. We present measurements of initial velocity and mass distributions of organic fragment ions desorbed from C, Al, and Au substrates by fast heavy atomic and molecular ion (e.g. 0.9 MeV N+/1.8 MeV N-2(+)) bombardment. We show that molecular ions can be used to control the local and temporal distance of nuclear track formation processes. Information on the dimensions of infra- and ultratrack is obtained from a comparison between secondary ion emission from binary molecular and single incident ions.