Abstract
The ionization Beam Cross section Monitor (BCSM) provides non-destructive measurements of transverse beam parameters in INR RAS proton linac. Operation of the monitor is based on utilization of residual gas ionization. The monitor enables to observe position, two-dimensional beam cross section, beam profiles obtained from it and emittance ellipses reconstructed from profiles data as well as their evolution in real-time within a wide range of energies and beam intensities. The BCSM design and image processing system are described. The monitor accuracy and precision analysis and estimations of influence of the linac radiation background are discussed. The available experimental results of proton beam transverse parameters measurements at the linac exit are presented.