Propagation of intense pulsed proton beam through z-discharged plasma channel in the presence of return channels

Experimental studies are presented on the propagation of an intense, pulsed, proton beam (890 kV, 50 ns) through a z-discharged plasma channel (50 cm long, 1.1 ∼ 10 Torr, air) in the presence of return channels (30 cm long). Using a high-speed camera and a small-sized magnetic probe, we have found the compression (deformation) of the main channel due to the presence of the return channels. The enhancement of the beam power density has also been observed. Good efficiency of the propagation (∼ 33 %) has been observed through the main channel.