Low-energy Electron Beam Profile Monitor.

A low-energy electron beam profile monitor has been developed and tested. It has been used to optimize the focusing of continuous electron beam of current up to 5 mkA and kinetic energy less than 20 eV. The device realizes the pin-hole camera method. The beam-sampling part of monitor is based on Nipkow disc principle, which allows investigating the beam cross section for one complete turnover. This made it possible to accelerate the measurement process in comparison with devices using the reciprocating movement of a collector with a hole. The monitor enables the determination of two-dimensional beam profile and measurement of beam current. The monitor was used to study the parameters of a low-energy electron beam gun designed to measure the work function of electrons from a metal by the Anderson method. The scheme is given and the operation of the experimental setup is described. The electrical signals received in the process of scanning together with synchronization pulses through the PCI-1802L adapter are transmitted to a personal computer, where a specially developed program collects and processes the received data. The measurement results are displayed on the computer monitor as a family of line graphs, 3D images and tables for each measurement cycle (disk turnover). The design incorporates low material and labor costs and minimal amount of devoted electronics. [ABSTRACT FROM AUTHOR]