In the homogeneous magnetic field superimposed with helically symmetric ele
ctrostatic one, the electron drift trajectory depends on the particle energ
y and on the particle velocity component relative to the magnetic held, The
se effects can be used. (1) to suppress gyrotron magnetron-injection gun in
Stabilities caused by electron reflection From the magnetic mirror and (2)
for separation of electron beam energy fractions in multistage depressed co
llectors.