Upgrading the Scanning Two-Dimensional Ionization Profile Monitor in Beam Transport Lines

Abstract

The scanning two-dimensional ionization profile monitor (IPM) has been upgraded for the beam diagnostics in beam transport lines. The main parts of the monitor are an extractor, a scanner, and two analyzers with a slit at which residual-gas ionization products collected from a beam path as long as 50 mm arrive. The current amplifier based on microchannel plates and a current collector are placed in sequence behind the slit in order to increase the IPM sensitivity under high-vacuum conditions (n × 10−6 Pa). Two-dimensional beam profiles are obtained by scanning. A special electronic unit containing high-voltage supplies and collector-current meters has been created for the scanning and IPM control. Three upgraded IPMs have been placed between the accelerator and the physical facilities in each beamline of the DC-280 FLNR JINR cyclotron. Data processing and simultaneous display of experimental results from several IPMs are carried out by a program developed in the LabVIEW design environment. The minimum current of the 40Ar ion beam with the energy of 5 MeV/nucleon at which the monitor is still operable is estimated to be several tens of picoamperes. The reliability of the upgraded IPM has been demonstrated by its operation.