Absolute measurements of electron-loss cross sections of He+ and C3+ with atomic hydrogen at intermediate velocities

Cross sections for electron loss of He+ and C3+ projectile ions on atomic and molecular hydrogen were measured in the 0.5-MeV less than or equal to E less than or equal to 3.5-MeV energy range. The measurements of the sigma(H2) / sigma(H) cross section ratios were made by using an absolutely calibrated hydrogen furnace. The influence of different models describing the form factor of molecular hydrogen is examined by means of the ratio sigma(H2) / sigma(H), which is sensitive to the model adopted, particularly in the case of He+ projectiles. The general behavior of the measured data is analyzed within the independent electron approximation including the electron loss (screening and antiscreening contributions), electron capture, and target ionization channels. The connection between the antiscreening mode and the electron impact ionization of multicharged ions is explored. [S1050-2947(98)04008-6]