Nikolai Alexandrovich Kaptsov (03.02.1883 – 10.02.1966) was a Soviet physicist. He graduated from Moscow University (1904), where he worked, with a break in 1911 — 18 (professor from 1931).
His research was in the field of gas-discharge physics, radio electronics, plasma physics and the history of physics. He studied the kinetics of electrons in systems that generate high-frequency oscillations, and put forward the idea of grouping electrons in space (phase focusing). He contributed to the physics of the corona of a high-voltage discharge, constructed a theory of the processes that take place near corona-discharging wires, and studied the part played by internal fields in a plasma as it forms.