Observation of strong self-focusing of an intense relativistic electron beam impinging on a SiO/sub 2/ target
- 1 January 1999
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Plasma Science
- Vol. 27 (5) , 1501-1509
- https://doi.org/10.1109/27.799832
Abstract
A substantial reduction in the spot size of an electron beam striking a SiO/sub 2/ target has been observed during a 60 ns pulse. We attribute this to the emission of positive ions, most probably protons, from the target. These are then accelerated upstream and focused along the axis by the electron beam, where they partially neutralize the space-charge of the beam, and produce a sharp pinch. A simulation of the effect with a particle-in-cell code provides an adequate quantitative description, and a simple model, based on space-charge-limited emission of protons by the target confirms qualitatively the results of the simulation. The presence of an aluminum foil on the upstream side of the target is shown to suppress the effect, probably by stopping the protons.Keywords
This publication has 6 references indexed in Scilit:
- Effect of target-emitted ions on the focal spot of an intense electron beamLaser and Particle Beams, 1998
- Pencil-like mm-size electron beams produced with linear inductive voltage addersApplied Physics Letters, 1997
- Design and initial operation of LELIA induction acceleratorNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1991
- Foil focusing of electron beamsJournal of Applied Physics, 1990
- Measurement of electron energy deposition necessary to form an anode plasma in Ta, Ti, and C for coaxial bremsstrahlung diodesJournal of Applied Physics, 1989
- Electron- and Photon-Stimulated Desorption: Probes of Structure and Bonding at SurfacesScience, 1986