Electron spectrometer

Abstract: A double‐focusing electrostatic electron spectrometer has been used to measure the K—LL Auger spectra resulting from electron impact for each of the elements in the gaseous molecules N2, O2, CO, NO, H2O, and CO2. An energy resolution of 0.09% full width half‐maximum was normally employed. A method for analyzing these complex spectra is described. It involves the identification of normal and satellite lines. The former are defined as arising from single electron ionization from the K shell without additional excitation followed by an Auger process in which one electron fills the vacancy while a second goes into the continuum, and where all the other electrons remain in their same orbitals. Satellite lines result when extra excitation occurs either in the initial formation of the K vacancy or in the subsequent Auger process. To aid in the identification of these satellite lines, auxiliary experiments have been performed such as the study of discrete energy losses in photoionization due to electron shake‐up,...

Abstract: Initially designed for scientific research, the first electron accelerators used for industrial purpose were installed in the 1950s. Electron beam accelerators are now used in diverse industries chiefly to enhance the physical and chemical properties of materials. Cross-linking of polymers used for wires, cables and heat-shrinkable products is a major application. Accelerated electrons are also used to inactivate microorganisms or to reduce the quantity of pathogens or toxic by-products in polluted waters. factsheet Over the last two decades the number of electron accelerators in use has dramatically increased.

Abstract: A correlation study of the sudden intensity increases seen in the 50–150 kev and 150–500 kev energy channels of the ATS 1 electron spectrometer with the occurrence of magnetic substorms recorded at midnight has been made. As a result of this study, the following conclusions applicable for times of moderate magnetic activity are arrived at: (1) Electrons are produced in the 50–150 kev energy range as observed at 6.6 RE during a magnetic substorm. The spectrum is soft since electrons are not always observable in the second energy window. (2) The electrons are produced at or near the midnight meridian and then drift on closed field lines around the earth. (3) The electron bunch produced as a result of the substorm in 75% of the 60 events studied is associated with precipitation observed by riometers as it drifts. An apparent dependence of precipitation on the level of substorm activity as given by the AE index suggests that the electrons are often produced of sufficient intensity to exceed a stable upper limit for trapped electrons at 6.6 RE. (4) The frequency of occurrence of such particle substorms indicates that they might represent a quasi-steady source of electrons for the trapped radiation.

Abstract: This article gives a detailed description of a single shot electron spectrometer which was used to characterize electron beams produced by laser-plasma interaction. Contrary to conventional electron sources, electron beams from laser-plasma accelerators can produce a broad range of energies. Therefore, diagnosing these electron spectra requires specific attention and experimental development. Here, we provide an absolute calibration of the Lanex Kodak Fine screen on a laser-triggered radio frequency picosecond electron accelerator. The efficiency of scintillating screens irradiated by electron beams has never been investigated so far. This absolute calibration is then compared to charge measurements from an integrating current transformer for quasimonoenergetic electron spectra from laser-plasma interaction.