Effect of the surface morphology on the energy transfer in ion–surface collisions

Time- and energy-resolved surface-induced dissociation (SID) of singly protonated des-Arg1-bradykinin (PPGFSPFR) combined with RRKM modeling was used to explore the effect of surface morphology on the energy transfer in collisions of large ions with surfaces. Experiments were performed in a Fourier Transform ion cyclotron resonance mass spectrometer (FT-ICR MS) specially configured for SID studies. Mass-selected and vibrationally relaxed ions were collided with three diamond surfaces of varying degree of roughness along the surface normal. The results demonstrate that internal energy distributions resulting from collisions of large ions with surfaces are rather independent of the surface morphology: the translational to vibrational (T → V) energy transfer efficiency is 19.5 ± 0.5% for all three diamond surfaces. However, the scattered ion signal increases by a factor of 2 with decrease in the degree of roughness of the SID target suggesting that smooth diamond surfaces are better targets for analytical applications.