Position-sensitive ionization detectors for ionizing beams diagnostics

Abstract Ionizing detectors for on-line non-destructive monitoring of the geometric parameters of ionizing beams have been proposed. Such a detector can be used on a beamline with a residual gas pressure of about 10 −3 –10 −6  Torr. It measures the product of ionization of the residual gas by the beam under investigation. An electric field moves the ions through a narrow slit into an analyzer. The analyzer field transforms the energy distribution of the ions into a two-dimensional space distribution on the outer analyzer plane. An Open Image Converter Tube (ICT) with an amplifier consisting of two Micro Channel Plates (MCP) forms an image of the real beam cross-section. This image is registered by a video camera, processed and stored on a computer. The detectors were successfully tested on beams of charged particles with wide energy and intensity ranges and on synchrotron radiation beams. Codes developed give the distribution of the beam density along its cross-section, beam profiles, the position of the center of gravity and its displacement. Statistical processing increases the signal/background ratio more than 10 times, and evaluates the position of the center of gravity with an uncertainty of about 1 μm.