Dynamics of Intense Pulsed Proton Beam in the Nagaoka ETIGO-I

Abstract

Dynamics of an intense pulsed proton beam have been studied by measuring nuclear reactions as well as by a biased ion-collector (BIC). When the ion-current density (J i) is small such that J i<30 A/cm2, the proton number measured by BIC is in good agreement with that by nuclear activation. Good linearity exists between time integrated γ-ray signal and proton number measured by the activation. Hence, it would be possible to obtain the proton number quantitatively even when a target "blow-off" takes place at J i>1 kA/cm2. Prompt γ-ray is also measured by the time-of-flight method to yield reasonable agreement with the applied peak potential.

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

“…It is seen that, as before, with time the cross section is deformed by the presence of return channels. The behavior of the proton beam propagating through the channel has been studied by carbon activation technique [13,14]. The reaction is 12 Cp, J 13 NE 13 C In order to observe the deformation of the main channel due to the presence of return channels, a rectangular slit (5 mm wide) was placed just in front of the carbon target, as shown in Fig.…”

“…For this purpose, several ideas have been proposed, such as a wall-initiated z-discharge plasma channel or a laser-initiated plasma channel [14]. In particular, the former is very simple.…”

“…An image converter camera and small-sized magnetic probes were used to observe the shape of the channels. propagation efficiency was determined by measurement of the number of protons, using a nuclear activation technique [13,14]. Figure 2 shows a typical waveform of the channel current.…”