Protons colliding with ice: Bouncing, sticking, splashing

Probing Molecular Solids with Low-Energy Ions

“…The orientation of the molecules following landing depends on the nature of the SAM. The molecular axis of V(benzene) 2 molecules in the H-SAM substrate remains at [70][71][72][73][74][75][76][77][78][79][80] • with respect to the surface normal (141). The molecular orientation of other complexes [M(benzene) 2 ; M = Ti or Cr] shows a similar trend, although chromiumcomplex molecules have a lower-than-70…”

“…Also, surface-sensitive tools, such as X-ray photoelectron spectroscopy (XPS), have been employed with TPD to study ice films (26,46). Ions whose energy ranges between 1 and 100 eV (47-71)-which is known as the hyperthermal energy regime and, especially with energies below 10 eV (9,72,73), constitutes the ultralow-energy regime-are novel probes for studies of new phenomena. Their novelty arises from the extremely short interaction time between the ions and the surface.…”

Dynamics of the sputtering of water from ice films by collisions with energetic xenon atoms

“…10 The net result of the presence of these quenching channels is the efficient dissipation of the collision energy from the incident projectile; this leaves little energy to desorb molecules from the surface. Sputtering of water from ice has been reported using protons, 24,25 Xe + , 26 He + and O + , 27 and Ar +12 with energies in the keV range, but sputtering with low (below 1 keV) energy neutrals has not been thoroughly examined.…”

“…Calculations predict sputtering yields of 10%-20% for exposure of crystalline ice to 0.1 to 4 eV protons, with no dependence on the incident angle of the protons. 24,25 This paper presents results from of a study where ice surfaces were sputtered by comparatively low incident energy (<7 eV) xenon atoms and show that, despite the ability of the surface to absorb energy, collision-induced desorption of water occurs when ice surfaces were bombarded with energetic xenon atoms. The sputter yields and CID cross sections for desorption of water from both H 2 O and D 2 O ices were determined, as well as the energy of the scattered xenon to better understand how collisional energy was exchanged.…”