INTERFEROMETRIC METHODS OF LOW-DENSITY PLASMA DIAGNOSTICS IN THE ACCELERATOR CHANNEL WITH THE SPACE-CHARGE NEUTRALIZED TRANSPORT OF THE BEAM

The feature of the projected accelerator is an ionic beam compression due to the neutralization of a spatial charge, which is a result of drift in the low-density plasma (1010-1012 cm-3). Two methods can be used for interferometric plasma diagnostics: homodyne and heterodyne methods. However, due to the relatively small magnitude of the phase shift at low plasma density, the application of the first method is inefficient. The scheme of the heterodyne interferometer to determine the plasma density in the accelerator channel with neutralizing drift of ions is detailed. For the spatial diagnostics of plasma, the methods of a two-exposition digital holographic interferometry with high temporal and spatial resolution are considered. Preliminary probe measurements allowed to estimate only the order of magnitude of plasma density.