This volume contains the full proceedings of the Fourth International Workshop on "Desorption Induced by Electronic Transitions" (DIET IV), held October 2-4, 1989, at the Burghotel Kranichberg, Gloggnitz, Austria. It followed earlier workshops held in Williamsburg, USA (1982), SchloB Elmau, FRG (1984), and Shelter Island, USA (1987). The workshop was attended by 77 participants from 9 countries, and 66 papers (8 invited, 24 oral contributions and 34 poster contributions) were pre sented. The proceedings contain 53 separate papers and focus on 8 main topics: (1) Basic Mechanisms and Theory, (2) Photophysics and Photochemistry, (3) Laser Induced Desorption, (4) Adsorbed Layers, (5) Condensed Gases, (6) In sulators, (7) Gas Phase Processes and (8) Applications and Related Processes. The workshop was opened by N. Tolk, who initiated this series of meetings in 1982, and by D. Menzel, who mentioned the 25th birthday of one of the basic processes in DIET, the so-called MGR model, which was first published in 1964. One of the goals of the meeting was to achieve a better understanding and further improved theoretical descriptions of desorption by electronic transitions.

Inhalt
I Basic Mechanisms and Theory.- New Theoretical Aspects in DIET.- Lifetimes of Excited Atoms near Surfaces.- Image-Screening of Positive Ions at Metal Surfaces, and Electronically Stimulated Desorption of Noble Gas Atoms.- Trajectory Calculations of Electron Stimulated Desorption of Positive and Negative Ions.- Excitation Lifetimes and Excited-State Forces in Chemisorbed Molecules.- II Photophysics and Photochemistry.- Surface Photochemistry.- Photon Stimulated Desorption of Fluorine from Silicon Etched by XeF2.- Substrate Mediated Photodissociation of NO2/N2O4 Adsorbed on Pd(111).- Photochemistry of Halogenated Molecules Adsorbed on Ag(111).- Photophysics and Photochemistry of NO on Ag(111), Cu(111), and Si(111)7×7.- Dissociative Desorption of CH3I by UV-Laser Radiation: Kinetic and Internal Energy of the Neutral Fragments.- Resonantly Enhanced Dissociation of Molecules into Excited Fragments Following Core-Level Excitation.- Resonances in Core-Level Shake-off Spectra of CO and N2 Adsorbed on Ni(100): Implications for Photon Stimulated Desorption.- III Laser-Induced Desorption.- Laser-Induced Desorption.- Desorption Stimulated by Collective Electron Excitation.- On the Mechanism of High-Yield Desorption.- Studies of Laser Sputtering of GaP by Means of Resonance Ionization Spectroscopy: Response of Clean Solid Surfaces to Photo-excitation.- Do Electronic Transitions Play a Role in Laser Etching? The Case of Cl2 on Si(100).- Intensity Dependence of Laser-Induced Emission of Particles from CaF2(111) near the Plasma Threshold.- Laser-Induced Ion Emission from Si and Ge Surfaces.- Adsorption and UV-Laser Desorption of NO/O/Ni(100).- IV Adsorbed Layers.- Electron Stimulated Desorption Ion Angular Distributions (ESDIAD) of Negative Ions.- Quantum-Resolved StimulatedDissociation and Desorption of Chemisorbed Molecules.- VeloCity Distribution of Laser Photoionized Neutrals Ejected from Methanol-Dosed Aluminum(111) by Electron-Stimulated Desorption.- Desorption and Secondary Ion Production During Bombardment of CO/Ni(111) with Ne+ and Ne++ Ions at Very Low Impact Energies.- Electron Stimulated Desorption of Hydrogen from Si(111) Surfaces Adsorbed with Hydrogen and Alkali Atoms.- Resonant Desorption of Negative Ions from Adsorbed Layers Bombarded by Very Low Energy Electrons.- Resonant Desorption from Clean and Carbon-Covered Alkali Halide Surfaces: State-Specific Detection by REMPI.- Processes of Desorption and Desorption Cross Sections with Electrons at Silicon Surfaces.- V Condensed Gases.- Ejection of Argon Dimers from Solid Argon Films Electronically Excited by MeV He Ions.- Erosion of Pure and Alloyed Ices of Rare Gases and Small Molecules by Core Excitation.- Role of Valence Double Photoionization Processes in Ion Desorption from Condensed Gases.- Photon Stimulated Desorption of Excited Neutrals from the Surface of Solid Ar.- Electron-Stimulated O Desorption from O2 Condensed on a Rare-Gas Film: Evidence for an Indirect Bounce Trajectory.- Lower Limits on the Absolute Dissociative Electron Attachment Cross Section from O2 Condensed on Rare-Gas Films.- A Comparative Study of Core-Induced Photon Stimulated Desorption and Electron-NEXAFS of Condensed H2O, NH3, and CH4.- VI Insulators.- Stimulated Desorption from Alkali Halides.- Hot Hole Diffusion in the Electron-Stimulated Desorption of Metal Atoms from Alkali Halides.- Different Processes for Desorption of Ground- and Excited-State Atoms Under Electron Bombardment of Alkali-Halides.- DIET of Neutral Excited State Hydrogen from Alkali Halide Surfaces.- Observation ofExcitonic Effects in Excited Neutral Alkali Desorption from Alkali Halides.- Electron-Stimulated Desorption of Neutral Ground-State Lithium Atoms from LiF and the Influence of Stored Defects.- Molecular Cluster Calculations of the Electronic Structure of the (111) Surface of CaF2.- ESD of Multiply Charged Ions from SiO2: A Search for Mechanisms.- Positive Ion Desorption from MgO by Low Energy Electron Irradiation.- VII Gas Phase Processes.- Single Photon Multiple Photoionization of Gaseous CO, C6F6, and trans-l,2-C2H4BrI.- Electron Induced Vibrational Excitation of Gaseous Polyatomic Molecules: The NH3 Case.- VIII Applications and Related Processes.- Useful Macroscopic Phenomena due to Laser Ablation.- Electron Stimulated Desorption of Nuclear Spin Polarized Alkali-Metal Atoms.- Mechanisms of Laser Ablation of Biological Tissue.- Electron Damage of a CH3OH Layer Adsorbed on Nb(110).- Role of Core Levels' Ionization in the Electron Induced Dissociation of Silicon Dioxide.- DIET in High-Temperature Superconductors.- A Study of the Initial Adsorption Processes of Oxygen on the Ti(1010) Surface by TOF-Type Electron Stimulated Desorption.- Index of Contributors.