Interaction between a thin polyethylene target and a relativistic electron beam

We investigate theoretically and experimentally the possibility of energy deposition enhancement when a beam interacts with a high-density plasma in the diode. The beam-plasma instability has been studied taking into account the angular spread of the beam, the e-i collisions and the density gradients. The beam (500 kV, 250 kA, 50 ns) interacts with a thin CH2 foil. The plasma expansion from the foil target is found to be symmetric. The temperature, estimated by XRD is 10 eV. The measured parameters (temperature, density, gradients), together with the theoretical study, show that the beam-plasma instability is ineffective in the expanding target.