Speaker
Description
The active target detector system ACTAF (ACtive TArget for FAIR) for applications in reaction studies with radioactive beams at small momentum transfer is a part of the R3B setup at FAIR. The design of the currently under construction detector inherited ideas from the active target set-up used in previous experiments at GSI but is heavily extended with respect to a larger variety of reactions and heavier beams up to uranium. Reactions like elastic proton scattering at intermediate energies, allow to precise determine the nuclear matter radii, and the radial shape of the nuclear matter distributions in these nuclei that are very basic nuclear characteristics important for nuclear structure theories and astrophysics. These experiments, among others, are not possible with any other method and anywhere else except of FAIR and thus, unique. This unique feather will be first used at CERN for an experiment measuring muon-proton elastic scattering for a determination of a proton radius. First time in the series of experiments aiming this, not only projectile but also recoil will be measured. The detector system is unusual in many aspects – absence of gas amplification, gas circulation and purification system, usage of FADC and pulse processing, Details of the operational principle, construction of the detector, its electronics and DAQ will be presented.
