LAUSR

The current stage of the upgrade of the DIMEX detector for studying fast processes on a synchrotron radiation (SR) beam is described. The current version of the DIMEX is a one-dimensional high-pressure ionization chamber with a fast electron component readout. The detector can record photon fluxes from each bunch separately without mixing photons from different bunches. The maximum flux the DIMEX can detect is limited by the space charge of positive ions in a high-pressure gas. To substantially improve this and other parameters of the detector, it was decided to switch to microstrip silicon technology. A prototype based on a silicon-microstrip sensor was developed along with a special integrated circuit (ASIC) for reading out the signals from this prototype. The first tests of the new DIMEX-Si prototype on an SR beam show that it is superior to the gaseous version in all respects. Results are presented from the first tests of the silicon-microstrip detector prototype on the SR beam of the VEPP-4M storage ring.