Fiber-based multichannel heterodyne interferometer for studying the pulsed plasma properties

A fiber-based four-channel heterodyne interferometer has been developed to study the properties of pulsed plasma. The accuracy of phase measurements was 0.03 rad, which corresponds to an error in measuring the concentration of free electrons of $\pm$1 $\cdot$ 10$^{19}$ m$^{-2}$. Measurements of the electron density and plasma velocity of the plasma accelerator have been carried out.