Ion-surface collisions

W. Heiland, C. W White (eds.) Inelastic Ion-Surface Collisions, Academic Press. New York 1977. 

G. Westmacott, F. Zhong, M. Frank, S. Friedrich, S. E. Labov, and W. H. Benner. Investigating Ion-Surface Collisions with a Niobium Superconducting Tunnel Junction Detector in a Time-of-Flight Mass Spectrometer. Rapid Commun. Mass Spectrom., 14(2000) 600-607. 

Hagstrum, H. D. Low Energy De-excitation and Neutralization Processes Near Surfaces. In Inelastic Ion-Surface Collisions, Tolk, N. H., Tully, J. C., Heiland, W., White, C. W. (eds.). New York, Academic Press 1977... 

Sigmund, P., in Inelastic Ion-Surface Collision, N.H. Tolk, J. Tully, C.W. Heiland and C.W. White (eds.) Academic Press, Oxford (1977). 

LL Haney, DE Riederer. Delayed extraction for improved resolution of ion/surface collision products by time-of-flight mass spectrometry. Anal Chim Acta 397 225-233,1999. 

Several reviewers have discussed the fundamental role played by dust in the physical processes occurring in planetary magnetospheres, leading to tori at Jupiter and Saturn and to planetary rings at Jupiter, Saturn, Uranus, and Neptune via sputtering of surfaces (Johnson, 1994 Johnson, 1996 Johnson et al, 1998). Plasma-dust interactions occur in the cometary atmosphere via a combination of solar radiation pressure, plasma drag (inelastic ion-surface collisions), and electromagnetic forces (Whipple, 1981 Whipple et al, 1985 Hartquist et al. 

Ion-surface collisions, particularly studies involving well-characterized, monoenergetic, mass-selected beams of low-energy ions (a few eV to 500 eV) incident on real surfaces... 

These detectors consist of conversion dynodes, a scintillator (normally a phosphorescent screen), and a photomultiplier tube (Figure 1.28). Cations and anions are accelerated to the negative and positive conversion dynodes, respectively. The ensuing ion-surface collisions lead to the generation of secondary elecfrons which strike the phosphorescent screen where they are... 

Ion activation is also accomplished by collisions of the fast-moving precursor ions with a solid surface [12,13]. This ion-surface collision technique, known as surface-induced dissociation (SID), can be implemented on a variety of tandem mass spectrometry systems, such as magnetic sector, TOF, quadrupoles, ion traps, and FT-ICR-MS, by placing a solid surface in the path of the ions [13]. The surface can be a bare metal (e.g., a stainless-steel plate) or a metal covered with self-assembled monolayers [14]. Ion-surface collisions are more efficient in terms of internal energy conversion because of the greater mass of the colliding surface [see Eq. (4.4)]. Consequently, compared to the CID process, in which a serious decrease in the dissociation efficiency is observed, ions of much higher mass can... 

Rau, C., and S. Eichner, 1981, in Inelastic Particle-Surface Collisions, Proc. Third Int. Workshop on Inelastic Ion Surface Collisions, eds E. Taglauer and W. Heiland (Springer, Berlin) p. 138. 

Tully JC, ToUc NH. In Tolk NH et al, editors. Inelastic Ion-Surface Collisions. New York Academic Press 1977. 

Table 1 Low energy polyatomic ions/surface collision processes ...

Surface effects in ion/surface collision processes are very prominent and continue to be actively investigated. For example, surfaces covered with hydrocarbon pump oil were found to be more effective in reducing neutralization (or increasing secondary ion yield, that is, the ratio of the total secondary ion current to the primary ion current measured at the surface) than clean metal surfaces. In addition, it was also found that the organic nature of the surface affected the energetics of the ion/ surface collision, especially the T->V conversion efficiency. 

Fragment ions produced by SID have been used to distinguish gaseous isomeric ions and to elucidate the structure of biomolecules. The unique characteristics of SID, narrow internal energy distribution and variable control of internal energy, make it a powerful tool for studying isomeric ions. Before low energy ion/surface collisions were used as a means of ion activation, isomeric ion distinction was performed... 

Figure 9 Product ion spectra resulting from 25 eV collisions of the pyrazine molecular ion (mlz 80) with (A) a D-SAM surface and (B) an F-SAM surface. Reproduced with permission from Winger BE, Laue H-J, Homing etal, (1992) Hybrid BEEQ tandem mass spectrometer for the study of ion/surface collision processes Review of Scientific Instruments 63 5613-5625.

This spectrum displays a wealth of peaks originating from various ion/surface collision processes including SID, ion/surface reaction, and chemical sputtering. The number and abundance of ion/surface reaction products (especially Si containing product ions) for this ion/surface pair may appear to be remarkable for what would intuitively be thought of as a relatively inert fluorocarbon surface. Indeed, it has been fovmd that the F-SAM surface is very reactive toward organometallic, metallic, and a few organic ions. 

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