Electronic spectroscopy of cold cations in a 22-pole trap by indirect methods

The confining capabilities of a 22-pole ion trap have been employed to mea-
sure electronic spectra of cations of astrophysical relevance. The ion trap
sits on the head of a closed cycle cryostat, enabling collisional cooling of the
confined ions with helium buffer gas. The relaxation of the ions
enables measurement of electronic spectra under conditions similar to the interstellar medium. The ions are mass selected before injection into the trap, ensuring that only a single species is probed at a time and eliminating the possibility of overlapping contributions from other molecules.

Most of the results presented in this thesis have been obtained by a resonant
two colour two photon dissociation approach (R2C2PD). However, this method
was found to be suitable only for certain molecules because of several inherent
disadvantages. In order to broaden the classes of molecules whose electronic
spectra can be measured, two other methods have been employed. The first one was Laser Induced Charge Transfer (LICT) and the second one was Laser Induced Inhibition of Complex Growth (LIICG). The latter is a novel method that has been developed and tested for the first time.