ENGINE VOLTAGE REQUIREMENTS USING SPARK PLUGS PRE-IONIZED WITH RADIOACTIVE GOLD

The advent of high compression engines in the automotive industry has placed an increased demand on the engine ignition system, principally the voltage necessary to initiate spark discharge. This paper describes an investigation of the effect of pre-ionizing the spark plug gap by means of radioactive gold-198. It was theorized that by radiating the spark gap, sufficient ionization could be produced to provide a path for current to flow and thus, reduce the voltage required to initiate discharge. The test results were negative. No reduction in secondary spark discharge voltage is realized through the use of the radioactive source under normal engine firing conditions. Although radiation produces a substantial voltage reduction at atmospheric pressures and temperatures, the thermal electrons produced at normal engine operating temperatures and pressures cause sufficient ionization to saturate the spark gap with ions, and no further amount of ionization can be achieved by a radioactive source.