A method for generating multi-stream electron beams is disclosed, the method including connecting an inner cathode to a cathode stalk, connecting an outer cathode to the cathode stalk, driving the cathode stalk with a pulsed power generator at a single potential, producing a first electron beam from the inner cathode, and producing a second electron beam from the outer cathode. Implementations of the method for generating multi-stream electron beams may include where each of the inner cathode and the outer cathode may include nested magnetically insulated coaxial diodes (MICDs). The first electron beam and the second electron beam can be generated with different energies. A multi-stream traveling wave tube (TWT) and an electron beam generating apparatus are also described.