Sausage Instability in a Proton-Beam Transport through Wall-Confined Plasma Channel

An instability observed previously in a 800-keV of proton-beam transport through a wall-confined, z-discharged plasma channel (l-m long) has been identified as a sausage type from measurements made using an image converter campera. Clear evidence of the sausage instability has been obtained from the streak and framing photographs. When the instability grows with time, the wavelength tends to increase. The pinch velocity of the channel has also been measured in a parameter space, which gives reasonable agreement with the existing theory.