The 4th Concept Detector for the ILC

The 4th Concept Detector is designed for high precision measurements of Physics processes accessible at ILC. It consists of four basic subsystems: a pixel vertex detector for high precision vertex definitions, impact parameter tagging and near-beam occupancy reduction; a cluster-counting low-mass drift chamber for robust pattern recognition with over 100 three-dimensional space-points each with about 55 μ m resolution, 3.5% specific ionization measurement; a high precision dual-readout fiber calorimeter, complemented with an EM dual-readout crystal calorimeter, both with time-history readout, for the energy measurement of hadrons, jets, electrons, photons, missing momentum, and the tagging of muons; and, an iron-free dual-solenoid to return the flux and provide a second field region for the inverse direction bending of muons in a gas volume to achieve high acceptance and good muon momentum resolution. All four subsystems separately achieve the important scientific goal to be 2-to-10 times better than the already excellent LEP detectors, Aleph, Delphi, L3, and Opal. All four sub-detector will be described along with their performance and Physics capabilities obtained with full simulation studies.