An analysis of ballistic parameters/mechanisms affecting efficiency in electrothermal-chemical (ETC) guns

Historically, electrothermal-chemical (ETC) gun firings have failed to achieve ballistic performance as measured by ballistic ratios (BRs) commensurate with those for conventional powder guns. In this paper, the ETC ballistic cycle is examined in an attempt to identify possible aspects of the ETC process leading to the lower-than-expected BRs. Results indicate that at least a partial answer may be the energy required to evaporate and dissociate the polyethylene and metal electrodes of the plasma capillary, state changes which occur in the combustion gases due to the higher temperatures of the plasma and radiative energy losses.