Date of Award


Degree Name

Master of Arts



First Advisor

Dr. John A. Tanis

Second Advisor

Dr. Mark Clark

Access Setting

Masters Thesis-Open Access


Cross sections for electron capture and loss associated with target ionization are measured for highly charged 0q+ (q=5,6,7,8+) ions colliding with helium at energies of 0.25 to 2.5 MeV/u. Experimentally, charge changed projectile ions are detected in coincidence with specific target recoil-ion charge states. The fraction of transfer ionization (TI) relative to total electron capture is measured and compared to previous studies. The results show that TI is responsible for a significant percentage of the total single-electron-capture cross sections even at high velocities. Ratios of double- to single-target ionization are determined when simultaneous ionization of the projectile also occurs. The results show that double-ionization of the helium target is much more likely (about 4-5 times) to occur when the Oq+ projectile ion is ionized than when it is not. R