Abstract:
A photocathode for electroradiographic and electrofluoroscopic apparatus which contains a stack arrangement of perforated foils of a material with a high atomic number, in particular, double layer perforated foils with two electrically conducting outer layers and an insulating layer arranged in between which obtains relatively high sensitivity and high resolution permitting its use in medical diagnostic apparatus is described along with method of manufacturing the photocathode.
Abstract:
A light source illuminates particles migrating in an electrophoresis chamber under the influence of a reversing polarity electric field applied between a pair of spaced electrodes which are in the form of thin conductive layers deposited on opposed end portions of the chamber. The light reflected from the particles migrating along the stationary layer of the chamber is imaged onto a circumferentially arranged grating on a transparent rotating disk and modulated thereby. The modulated reflected particle light image is then applied to a photomultiplier tube which in response produces a spectral output signal which is subsequently applied to a frequency translating circuit where it is heterodyned down to the zero frequency region and offset relative to a reference frequency such that the heterodyned signal has a frequency content which is related to mean mobility and a polarity with respect to the offset reference frequency which serves as an indication of the polarity of the charge of the particles migrating in the chamber. A Real Time Analyzer or a frequency tracking circuit may be employed to convert the translator output signal to a mobility histogram or to an accurate measurement of mean mobility, respectively.
Abstract:
An electrostatic charged-particle analyzer includes a deflecting electrode system which focuses charged particles emitted from a sample by irradiating the sample with a primary beam, the particles being focused on the axis of the primary beam or on an identical circumference about the axis, and a cylindrical mirror type analyzer whose object point is the focusing point, whereby the accepted solid angle for the charged particles is made large.
Abstract:
An arrangement relating to the prevention of the alteration of the primaryeam by unwanted particles, such as sputter products, charged ions and electrons and their secondary processes, and to the resulting local improvement in the operational vacuum in electron-beam devices, ion-beam devices and in electron-energy analyzers and ion-mass analyzers using only three-dimensional metallic microstructures known as particle traps. Substantially all the flat parts of the components of the instrument seen by the beams, such as electrodes, diaphragms, screening plates, housing walls and the like, consist of a metal having a low atomization rate and a very low desorption rate, such as titanium or zirconium or similar substances and their alloys. Apertures of less than 0.5 mm in diameter, situated close beside one another and extending substantially perpendicular to the surface, are provided in the surfaces of the components of the instrument, between which apertures a lattice structure remains located in the surface, the depth of the apertures being equal to or larger than their opening cross-section and the total cross-sectional area of the apertures corresponding to at least half the metal surface occupied thereby.
Abstract:
The method consists in subjecting a sample of insulating material to photon radiation and in measuring the energy of the photoelectrons emitted by the sample under the action of the radiation. The sample is fixed on a metal sample-holder having a shape such that a portion of this latter is subjected to radiation. The emission of electrons of low energy is thus initiated and the positive charges which appear at the surface of the samples with the emitted electrons are neutralized by creating in the vicinity of the sample surface a space zone in which the electric field is substantially zero.
Abstract:
A phototube includes a cup-shaped apertured electrode interposed between a substantially flat cathode and an electron collection electrode. Anapertured electrode is coaxially secured within the recess of the cup-shaped electrode in parallel spaced-apart facing relation to the cathode.
Abstract:
A pyroelectric detector employing a substrate supporting a thin, i.e., 0.5 to 5 .mu.m thick, solid layer of pyroelectric material with an intermediate layer of nucleating material, i.e., a material which is wettable by a solution of the pyroelectric material so that an adherent continuous layer is formed thereon. The pyroelectric layer may be in the form of a mosaic of islands separated by an electrically conductive material covered with an electrically insulating material.
Abstract:
An electron-optical image tube including a photocathode, an extraction electrode consisting of a mesh on the emission side of the photocathode, and a focussing electrode on the side of the mesh remote from the photocathode, achieves increased time resolution, improved spatial resolution, and reduced magnification at a phosphor screen by making the photocathode to mesh spacing small compared with the mesh to focussing electrode spacing. An improved photocathode plate avoids large electric fields at sharp points on the photocathode surface. Additional annular electrodes and flared deflector electrodes in the drift section of the tube prevent scattering of electrons from the tube walls on to the screen.
Abstract:
The photoelectric surface of a photocathode made of a semiconductor single crystal is made minutely rough and, accordingly, lusterless, so that the transmissivity of a polarized light beam incident on the photoelectric surface is almost unaffected by the direction of electric field vector of the beam.
Abstract:
As a photoconductive material there is provided a carrier having a coating thereon of a germanium-sulphur-lead alloy or a germanium-sulphur-tin alloy.