Search for a possible isotope effect in charge-changing collisions involving hydrogen and deuterium

Charge equilibrium fractions F_{1 infinity}, F_{0 infinity} and F_{1 infinity} and relative charge-changing cross sections σ₁₀ and σ₀₁ were measured for the four possible combinations among hydrogen and deuterium beams and targets, namely H⁺-D₂, H⁺-H₂, D⁺-D₂ and D⁺-H₂. Within experimental errors of less than 0·3% for F_{0 infinity}, 1·2% for F_{1 infinity} and 2% for both F_{1 infinity} and the relative cross sections, no systematic differences for these isotope combinations were found in the velocity range 1·38 × 10⁸ to 2·24 × 10⁸ cm s^-1. Neglecting the small negative charge fraction, the ratio σ₁₀/σ₀₁, given by F_{0 infinity}/F_{1 infinity}, agrees to within 1·5% for the different combinations studied.