Multichannel detectors of monitoring system for the FODS installation

A system for monitoring proton beam of 70 GeV energy and 106-1012 proton/s intensity intended for experiments at the FODS two-arm focusing spectrometer is described. The same multichannel detectors operating as ionization chambers in air at 105 Pa pressure at 106-109 proton/s beam intensity or as chambers of the secondary emission for 109-1012 proton/s intensities were used for monitoring the proton beam. Coincidence of (10-12-10-9) A detector currents in these regimes permits to create an automatized monitoring system on the base of a common multichannel electrometric apparatus. Detector design is symmetrical relative to safeguard electrode and consists of two multichannel signal electrodes, four high voltage and protective screens. Distance between electrodes is 5 mm. High-voltage electrodes and input windows of protective screens are made of aluminium foil of 2 mg/cm2 density. The signal electrode represents a flat fibro-glass laminate frame with metal foil bands not contacting between themselves. Measurements of currents from bands are carried out by electrometers providing 1 V output signal at 10-10 A input current. A measuring system consisting of detectors and electronic apparatuses with the total number of channels equal to 144 operates in the regime synchronous to the accelerator. It provides obtaining distributions of intensity density, position of coordinates of gravity centers and angular characteristics for an intensive extracted proton beam of high density both during adjustment and FODS facility operation