Controlled scale amplifier of signals from detectors of extracted proton beam intensity

An amplifier designed for the operation in the monitoring system of extracted proton beam when measuring intensity in the range from 3x106-5x1012 protons/s is described. The range of measured charges is 5x10-13-5x10-8 deg C. The transformation coefficient is established with an accuracy of 0.5% by means of a computer or manually with relative change 1:2:5:10:20:40:100. The amplifier comprises an input cascade and a controlled integrator made with the help of operational amplifiers with input field-effect transistors. Four chambers with massive and grid electrodes were used as detectors. Two operation modes were envisaged: ionization made at the intensity less than 109 protons, secondary emission made at the intensity higher than 109 protons. The preservation of metrological amplifier characteristics in a wide range of beam intensity permitted to improve measurement accuracy and made it possible to perform absolute calibration of instrumens for measurement of intensity during fast extraction of a beam from an accelerator