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The optical properties of thin films of poly(butene‐1‐sulfone), PBS, an electron beam resist, are presented for the range of photon energies from 2.5 to 39.0 eV. The density of these films is found to be (1.39 ± 0.02) g cm−3. A sum‐rule calculation is used to demonstrate the overall consistency of the data obtained. The optical data are used to calculate inelastic electron mean‐free paths in PBS as a function of incident electron energy from 100 to 10 000 eV.

Theoretical models and calculations are combined with experimental optical data to determine a model energy-loss function for SiO2. Sum-rule checks and comparisons with experimental information are made to insure overall consistency of the model. The model energy-loss function is employed to calculate electron inelastic mean free paths and stopping powers for electrons with energies ? 10 keV in SiO2.

A theoretical description of the inelastic interactions of electrons with solid polystyrene is presented. The response of the valence electrons to energy and momentum transfers is determined by a model insulator theory; carbon K-shell ionization cross sections are derived from atomic, generalized oscillator strengths. Contributions to the inverse mean free path and stopping power due to these two excitation processes are derived and tabulated for incident electrons with energies from 10 eV to 10 keV. Electron ranges in the continuous-slowing-down approximation are calculated and tabulated for electrons with energies from 15 eV to 10 keV.

Inelastic mean free paths and energy losses in aluminum metal are calculated for electrons with energies from a few eV to 10 4 eV above the Fermi level. We have represented the contribution from excitations of the valence electrons by using an electron gas model. The effect of damping in the electron gas on the mean free path and energy loss is included within the context of the Mermin-Kliewer-Fuchs model of the electron gas dielectric function. The influence of core polarizability and local field corrections are discussed briefly. The contributions to the mean free path and energy loss of electrons from ionization of inner shells have been evaluated from atomic models. Comparisons are made with experimental data taken over a wide range of energies.

The real and imaginary parts of the complex refractive index, n(..omega..) = n(..omega..)+ik(..omega..), of arc-evaporated carbon films have been obtained over the range of photon energies h..omega.. from 0.5 to 62.0 eV. Values of k(..omega..) obtained from transmission measurements in this energy range were combined with values of k(..omega..) from the literature in the infrared and soft-x-ray regions. A Kramers-Kronig analysis then yielded the values of n(..omega..). The density of the arc-evaporated carbon films was found to be 1.90 +- 0.05 g cm/sup -3/ by the ''sink-float'' method, and their thicknesses were determined optically. A sum-rule calculation yielded the effective numbers of valence and core electrons to be 4.2 and 1.8, respectively. The experimental values determined for n(..omega..) have been used to estimate values of the inelastic mean free path ..lambda..(E) for electrons of energy E from 200 to 3000 eV in amorphous carbon. Good agreement is found between ..lambda..(E) and experimentally determined values of electron attenuation length L(E) from the literature.

Many-body theory is used to calculate the inverse mean free path for plasmon excitation by an electron in a free-electron gas with damping of the plasmon states included. The theory is applied to the special case of Al for which experimental data on damping of the plasmons are available. Numerical calculations indicate an appreciable probability for exciting plasmons by incident electrons with energies below the threshold energy predicted by “no-damping” theories. Die Vielteilchentheorie wird benutzt, um die inverse mittlere freie Weglange fur Plasmo- nenanregung durch ein Elektron in einem freien Elektronengas bei Einschlus der Dampfung der Plasmonenzustande zu berechnen. Die Theorie wird auf den speziellen Fall von Al angewendet, fur das experimentelle Werte der Dampfung der Plasmonen vorliegen. Numerische Rechnungen zeigen eine betrachtliche Wahrscheinlichkeit fur die Anregung von Plasmonen durch einfallende Elektronen mit Energien unterhalb der Schwellenenergie, die durch die Theorie ohne Berucksichbigung der Dampfung vorhergesagt wird.

An insulator model, with parameters fixed by fits to optical data, is used to determine the energy‐loss function describing the response of valence electrons in poly(butene‐1‐sulfone). Generalized oscillator strengths describe the response of the inner shell electrons. This theoretical information is employed to calculate inelastic mean free paths and stopping powers in poly(butene‐1‐sulfone) for electrons with energies ≤10 keV.

A theoretical description of the inelastic interactions of low-energy electrons (E?10 keV) with solid organic insulators is presented. The response of the valence electrons to energy and momentum transfers is inferred from a model for the energy-loss function with parameters fixed by optical data. With this model energy-loss function, inverse mean free path and stopping power due to interactions with the valence electrons are calculated for several organic solids. Contributions to the inverse mean free path and stopping power due to K-shell ionization in carbon, nitrogen, and oxygen are obtained from theoretical atomic generalized oscillator strengths. Simple, analytical formulae are deduced which allow predictions of mean free paths and stopping powers for electrons in the energy range 100 eV?E?10 keV to be made for a large group of organic solids.

The prospects for obtaining better theoretical calculations of experimentally interesting electron interaction effects, over a wide range of electron energies, are now considerably improved through the development of models for valence electron excitation in simple insulators and through the availability of theoretical atomic generalized oscillator strengths for inner shell electron excitation in several low-Z atomic systems. We describe briefly the way in which this information may be used to calculate mean free paths, stopping powers, and electron slowing-down spectra in Al metal and the insulator Al2O3.

The interaction of a relativistic electron with a system of plasmons is considered. First-order perturbation theory is used to calculate the rate of excitation of plasmons by the incident electron; the excitation rate leads to a mean free path. It is shown that relativistic corrections to the mean free path are generally quite negligible and thus the mean free path calculated using a nonrelativistic incident electron, when expressed in the “proper fashion”, is also correct relativistically. Es wird die Wechselwirkung eines relativistischen Elektrons mit einem Plasmonensystem betrachtet. Storungsrechnung erster Ordnung wird benutzt, um die Anregungsrate der Plasmonen durch die einfallenden Elektronen zu berechnen; die Anregungsrate fuhrt zu einer mittleren freien Weglange. Es wird gezeigt, das relativistische Korrekturen zur mittleren freien Weglange im allgemeinen vollig vernachlassigt werden konnen und die unter Annahme eines nichtrelativistischen einfallenden Elektrons berechnete mittlere freie Weglange auch relativistisch korrekt ist, wenn sie in der „richtigen Weise” ausgedruckt wird.

The interaction of a fast charged particle moving in a free-electron gas is described in the random phase approximation (RPA). The mean free path for the second order process of double-plasmon excitation in the free-electron gas is calculated. We find that the inverse mean free path for the double-plasmon excitation process is related to the inverse mean free path for single plasmon excitation by λ = 0.0103 rλ−1p. Thus, for electron densities corresponding to those in a real metal (1 < rs < 6) double-plasmon excitation may be important in the interpretation of certain experimental results as, for example, characteristic energy loss measurements. Die Wechselwirkung schneller, geladener Teilchen, die sich in einem Gas freier Elektronen bewegen, wird mit der „random phase”-Naherung (RPA) beschrieben. Es wird die mittlere freie Weglange fur den Prozes zweiter Ordnung der Plasmonen-Zweifachanregung in dem Gas freier Elektronen berechnet. Es wird gefunden, das die inverse mittlere freie Weglange fur den Doppelanregungsprozes der Plasmonen mit dem der Einfachanregung der Plasmonen durch λ = 0.0103 rλ−1p verknupft ist. Fur Elektronendichten, die denen in realen Metallen (1 < rs < 6) entsprechen, kann somit Doppelanregung von Plasmonen bei der Interpretation gewisser experimenteller Ergebnisse, wie zum Beispiel Messungen charakteristischer Energieverluste, bedeutend werden.

Monochromatic photons between 775 and 500 A were incident almost normally (15°) on the surface of liquid hexamethyl phosphoric triamide (HMPT). Incident and reflected beam strengths were measured with a double ion chamber filled with argon and the current leaving the cup of liquid was determined. After subtracting a portion of the current due to Ar+ drift into the cup, we obtained the photocurrent and, hence, the absolute photoemission yield. The yield falls from 9% at 16 eV to 5% at 25 eV. Such a falloff with increasing photon energy is expected from theory. The values are about double those calculated from theory using a three‐step model for the photoemission and using the Born approximation to calculate electron mean free paths. Conversely, if the experimental yields are used in the three‐step model, the electron mean free paths calculated from the data range from about 935 A at 16 eV to about 80 A at 24 eV and are about two to three times the theoretically predicted values.

The interaction of electrons with the solids Al and Al2O3 is described based on the electron gas model for the conduction band electrons in Al, a model insulator theory for the valence electrons in Al2O3, and inner shell ionization derived from atomic, generalized oscillator strengths. Contributions to the inverse mean free path and stopping power from the various interaction processes are tabulated for electron energies from 0.5 eV to 10 keV for Al and from 10 eV to 10 keV for Al2O3. Electron range in the continuous-slowing-down approximation and straggling are tabulated for electron energies from 10 eV to 10 keV for both materials.

This report summarizes experimental and theoretical studies designed to yield information on the interaction of ionizing radiations with various communications materials. The optical properties of Kapton have been measured over the energy range from 0.5 eV to 76 eV. Theoretical models combined with experimental optical data have been used to calculate mean excitation energies, mean free paths, and stopping powers for low-energy electrons (100 eV to 10 keV) in various solid organic insulators. The contribution to both the mean free path and stopping power due to K-shell ionizations in carbon, nitrogen, and oxygen where then obtained from theoretical atomic generalized oscillator strengths and added to the valence electron contributions. A model involving the diffusion of excitons has been proposed to explain data, reported in the literature, showing that a thin metallic surface layer may partially protect organic crystals against radiation damage. The stopping powers of several metals for electrons have been calculated from an electron gas statistical model and used to calculate the continuous slowing-down-approximation range and range straggling for electrons with energies or = 10 keV. Microdosimetric calculations have been made of the structure of heavy-ion tracks in silicon. Results show that these tracks are very small in lateral extent compared with the dimensions of critical volumes in currently used microelectronic components.

A simple expression is presented which can be used to estimate the mean free paths of electrons in solid organic insulators as a function of the electon energy. Input parameters are the molecular weight and the density of the organic sample. The range of validity is 100 eV to 10 keV. It is demonstrated that, for this class of materials, the electron mean free path is, to a good approximation, inversely proportional to the valence electron density for a given electron energy.

Previous results for the energy loss per unit path length and inelastic mean free path of an electron with energy less than or equal to 10 keV are modified by including an exchange correction, a sum-rule constraint, and a small relativistic correction. These new results are compared with the previous results, tabulated values, and predictions from ''universal'' formulae for organic solids.