Baowei Ding

Note: A two-dimensional position-sensitive micro-channel plate detector with a cross-connected-pixels resistive anode and integrated spectroscopy amplifiers

Based on the charge-division method, a compact detector system for charged particles is constructed. The system consists of a pair of micro-channel plates, a novel two-dimensional position-sensitive cross-connected-pixels resistive anode, and specially designed front-end electronics that can directly drive analog-to-digital converters. The detector is tested with an 241Am α-source. A position resolution of better than 0.3 mm and a maximum distortion within 0.5 mm in the active dimensions of 100 mm diameter are achieved.

TRANSFER IONIZATION IN COLLISIONS OF PARTIALLY STRIPPED Fq+ WITH HELIUM ATOMS

The cross-section ratios R of transfer ionization to single electron capture of Helium atom induced by fluorine ions in the strong-interaction region were measured by means of the position-sensitive-detection and the time-of-flight (TOF) technologies. The velocity and charge state dependence of R were studied. It is found that the R decreases when the 2q/v increases, where q and v are the charge state and velocity of projectile respectively. In this energy region the transfer ionization can be look as Two-Step process that one target electron is captured, and another electron is ionized.