An advanced molecular-beam surface-scattering apparatus for studies under extreme conditions

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We propose an advanced molecular-beam surface-scattering apparatus optimzed for studies under extreme conditions. This instrument goes well beyond the capabilities of our existing machine with regard to the following parameters: 1) accessability of extreme surface temperatures and extreme incidence energies, 2) product detection by optical methods (REMPI; soft VUV photoionization) as well as electron impact ionization mass spectrometry, 3) dual molecular beam geometry for reactive scattering, and 4) interfacing with an existing nanoparticle soft-landing apparatus. The new instrument will extend our understanding of Born Oppenheimer breakdown as it will enable studies where large amounts of energy (high temperature, high translational energy) are exchanged between a molecule and the surface. New types of reactions (e.g. surface ionization by proton transfer) are also possible. Studies on reactive scattering will elucidate the importance of nonadiabatic influence in chemical reactions, i.e. show how the energy flow between the electronic and nuclear (vibrational) degrees of freedom suppresses or enhances chemical reactions. Conversion of chemical to optical energy – a so far unobserved channel – will be studied using surface-coupled quantum well structures.