Stabilization of the phase-space portrait parameters of a hydrogen ion beam

Abstract

This investigation carried out variations in the transverse phase-space portrait of an ion beam during a 200-μs pulse of a proton injector in the linear accelerator at the Institute for Nuclear Research. The parameters of the accelerated 400-keV beam at the entrance into the beam transport channel and the beam from the ion source were measured. Numerical simulation of ion-beam acceleration in the proton injector was performed. The noiseless mode of beam generation in the duoplasmatron was obtained. The generator of the duoplasmatron discharge current with a discharge current instability of ±1% or less was developed and put into operation. A compensated resistive-capacitive voltage divider was used in the accelerating tube. The beam emittance measurements showed that the variations in the phase-space portrait of the beam from the upgraded injector during the 200-μs pulse were absent within the measurement accuracy. The normalized emittance for 90% of the beam current was 0.15π × cm × mrad at an ion current of 65 mA.