Active target time projection chamber project at Michigan State University

11h GANIL seminar room (105)

a coffee will be served 15mn before

Nuclear reactions using radioactive beams are growing in importance as a probe of structures or reaction dynamics of unstable nuclei. Reactions in inverse kinematics often involve low energy reaction products, which usually set a limit on a target thickness due to a strong stopping power. An active target time projection chamber, AT-TPC, currently under development at the National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, overcomes this difficulty with a tracking gas medium simultaneously acting as a reaction target. This defining feature enables us to measure ion trajectories inside the reaction target. The AT-TPC thus allows to increase the target thickness with retaining the quality of ion detection, thus making it capable of exploring nuclei further away from the line of stability or reaction processes with smaller cross sections. The AT-TPC is highlighted with an unprecedented active volume, a highly granular readout plane and the rigidity analysis capability using a solenoid magnet, which will realize high resolution and efficient measurements at the future re-accelerated radioactive beam facility of the NSCL. To study feasibility of envisioned detector technologies as well as to produce scientific results at early stages of the project, a half scale prototype was completed and commissioned in 2011. A couple of radioactive beam experiments were performed at the Twinsol facility at the University of Notre Dame. In this talk, the current status of the AT-TPC project will be presented with a focus on the prototype and the experiments at Notre Dame.