A PF-1000 device working with a deuterium gas filling and a current on the order of 1 MA was used for studies of the pinch-column structure by means of a laser interferometric system at a period of hard X-ray (HXR) and neutron production. Three different phases of the plasma-column evolution, corresponding to the intense HXR and neutron emission, were studied for discharges with neutron yields equal to about 10 11 neutrons/shot. First, the start of the stagnation of a pinch column was considered; as the second phase, the development and disruption of constrictions was studied, and as the third phase, the decrease of the plasma density in a part of the plasma column during its stagnation was considered. Regions of the probable electron and ion acceleration and possible neutron production were identified.