Measurements of electron‐beam (e‐beam) energy deposition in gaseous medium by a segmented totally stopping calorimeter and a pressure jump method are described, both of which gave the same values. Typicale‐beam parameters are 2 MV, 80 kA, and 65 ns (FWHM). Thee‐beam cross‐sectional area is 10 cm in diameter. First, the radial distribution of thee‐beam current generated from the field‐emission diode as a function of the axial magnetic field was measured. Next, for applications to longitudinal excitation of the high‐power gas lasers, thee‐beam energy deposition characteristics are measured in N2for the propagation distance up to 2.3 m in terms of the axial magnetic field, the N2gas pressure, and the radiale‐beam distribution. As a result, the axial field equivalent to the self‐magnetic field of the electron beam can acceptably control thee‐beam generation and propagation uniformities.