INFLUENCE OF COOLING TIME ON THE INTERNAL ENERGY OF IONS SUBJECTED TORESONANCE EXCITATION IN A QUADRUPOLE ION-TRAP

This study demonstrates the influence of cooling time, applied prior t o (and after) resonance excitation, on the internal energy carried by ions subjected to tickle excitation. Competitive fragmentations of ion ized butylbenzene have been used to estimate the internal energy avera ge transferred during collision processes. Two competitive effects hav e been observed by using a delay time before tickle: kinetic energy re laxation (up to 15 ms) related to an internal energy decrease effect a nd, at higher cooling time values, collisional excitation with helium buffer gas allows one to increase the internal energy of precursor ion s.