Abstract
The influence of the plasma density scale length on the production of MeV protons from thin foil targets irradiated at has been studied. With an unperturbed foil, protons with energy were formed in an exponential energy spectrum with a temperature of . When a plasma with a scale length of was preformed on the back of the foil, the maximum proton energy was reduced to and the beam was essentially destroyed. The experimental results are consistent with an electrostatic accelerating mechanism that requires an ultrashort scale length at the back of the target.
- Received 14 July 2000
DOI:https://doi.org/10.1103/PhysRevLett.86.1769
©2001 American Physical Society