B. Nees

Dependence of the desorption yield for valine on the charge state of the primary ions

Abstract The yield for molecular ions desorbed from a valine sample has been measured as a function of the charge state of the incident fast heavy ions. The data can be interpreted in the following way: (i) the yield depends on the square of the primary ion charge, and (ii) desorption takes place not only at the sample surface but also within a layer underneath. The depth of this layer is smaller than the depth needed to achieve charge state equilibrium for the primary ions.

Fast heavy ion induced desorption: Dependence of the yield on the angle of incidence of the primary ions

Abstract The yield for secondary ions desorbed from organic samples (amino acids) by 9 MeV oxygen ions has been investigated for different angles of incidence θ of the primary ions. Primary ions with definite charge states and an equilibrium charge state distribution have been used. The yield increases rapidly with θ and deviates strongly from a (cos θ) 1 distribution at large angles.

Energy dependence of fast heavy ion induced desorption of secondary ions

Abstract Yields for positive and negative secondary ions desorbed by 12C, 160 and 32S ions with velocities ν≳109cm s 1 and equilibrium charge state distributions have been measured. The data show that the yields depend on the charge and the velocity of the primary ions and the secondary ion species. They are independent of the primary ion mass.

Fast heavy ion induced desorption: Dependence of the yield on the primary ion energy

Abstract The dependence of the secondary ion yield on the energy of the fast primary ions has been investigated for several organic samples. We find different dependences for positive secondary ions desorbed from polar and ionic compounds as well as for positive and negative secondary ions desorbed from the same sample (polar compounds).

Accelerator studies in heavy ion induced desorption mass spectroscopy

Abstract The yield of molecular ions desorbed from a valine sample by fast heavy ions ( 32 S, 16 O, 12 C) has been investigated as a function of the primary ion parameters mass, energy and charge state. The measurement indicate that primary ions initiate the desorption only within a thin surface layer (a few molecular layers).

Langmuir-Blodgett films investigated by means of the spontaneous desorption mass spectrometry

It is shown that spontaneous desorption mass spectrometry is a sensitive tool for the analysis of Langmuir-Blodgett (LB) films made of fatty acids and fatty acid salts. It is particularly suited to detecting defects in the LB films, e.g. pinholes built in during film preparation.

Nuclear glory scattering in the 16O + 16O collision

Abstract Elastic 16O + 16O scattering data have been analyzed by means of a phase shift analysis with regard to the possible existence of nuclear glory scattering. The data contain all features necessary for a nuclear glory.

Intermediate-structure resonances in the /sup 16/O+/sup 16/O total reaction cross section

The

Intermediate-structure resonances in the O 16 + O 16 total reaction cross section

^{16}\mathrm{O}

Dependence of the heavy-ion-induced desorption yield on the primary-ion energy loss.

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