Suppression of two-stream hose instabilities at wavelengths shorter than the beam’s transverse size

Transverse hose instability may disrupt the propagation of a charged-particle beam in a channel of oppositely charged particles. A theoretical model predicts stabilization of this two-stream instability when the instability wavelength becomes smaller than the beam’s transverse size in a frame of reference where the instability’s phase velocity is nonrelativistic. Suppression of short-wavelength instability is also predicted when a proton beam propagates through a channel consisting of electrons and positive ions, consistent with previous experimental results.