Dense plasma diagnostics by fast proton beams

Abstract

Coulomb energy losses by 3-MeV protons in a capillary discharge channel are used as a diagnostics tool to measure the plasma density. By combining the proton energy loss data with the electron temperature measurements,we have been able to diagnose the free electron density ${n}_{\mathrm{fe}}=6.4\ifmmode\times\else\texttimes\fi{}{10}^{19}\phantom{\rule{0ex}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$ in a 3.3-eV ${\mathrm{CH}}_{2}$ plasma to an accuracy of $\ifmmode\pm\else\textpm\fi{}17%$. A considerably better accuracy can be expected for higher values of the electron temperature.