Charge Pickup Interactions of Relativistic Gold Nuclei

This thesis reports a measurement of the mass loss and velocity change associated with nuclear charge pickup by 1 GeV/nucleon gold nuclei interacting in a glass target. Solid state nuclear track detectors were used to determine the ionization rate, magnetic rigidity, and stopping range of each nucleus. From these data, I calculated the charge, mass, and velocity of each nucleus. This is the first instrument to measure magnetic rigidity with passive detectors separated by vacuum gaps. Since passive detectors do not provide time information for each event, and because the nuclear trajectories cross over each other as they traverse the vacuum gaps, novel data reduction techniques were required to match the data from the different detector elements. I also developed a new procedure to calibrate the ionization rate data more accurately. For six of the charge pickup events, I had sufficient data to determine both mass and velocity. The mean mass loss was 5.6 +/- 0.9(random) +/- 1.4(systematic) nucleons out of an initial mass of 197 for the gold. The mean velocity change during charge pickup (-0.0002 +/- 0.0006(random) +/- 0.0008(systematic)) was consistent with zero. These results agree with the results of Binns et al., who also reported a velocity change consistent with zero. My results conflict, however, with that of Gerbier et al., who reported a velocity decrease of 0.004 c accompanying their charge pickup interactions. Although Gerbier et al. used a less accurate calibration technique, the effect of this error would not have been sufficient to account for such a large discrepancy between our results.