A study of the bubble formation mechanism in a hydrogen bubble chamber using electron and positron tracks

The mechanism of bubble formation in liquid hydrogen was studied by measuring the difference in bubble density on electron versus positron tracks. The measured difference is consistent with the Seitz-heat spike theory and suggests that it is secondary delta rays with energies well above the ionization potential that participate in bubble formation. These data are also consistent with the observation of no relativistic rise in bubble density for liquid hydrogen.