Autoacceleration of intense electron beams by coaxial cavity structures Available to Purchase

Tonks’ theorem and Faraday’s law are applied to study the autoacceleration interaction of an intense hollow beam with a coaxial transmission line cavity, assuming the constant‐current approximation. The autoacceleration voltage is found proportional to the beam current and the inductance per unit length of the coaxial transmission line. Comparison with experimental data indicates that the coupling coefficient α is of the order 2/3. The creation of a virtual cathode near the autoacceleration region under certain beam and geometry conditions gives rise to a virtual cathode accelerating voltage. This voltage is found to be proportional to the inductance per unit length of the annular region between the hollow beam and the drift tube as well as the amount of charge per unit length reflected from the virtual cathode. The ratio of the virtual cathode voltage to the autoacceleration voltage is a small number and for optimum operating conditions it should be minimized.