"The active target and time projection chamber (ACTAR TPC) is a novel gas-filled detection system that will permit new studies into the structure and decays of the most exotic nuclei. The use of a gas volume that acts as a sensitive detection medium and as the reaction target itself (an “active target”) offers considerable advantages over traditional nuclear physics detectors and techniques. In high-energy physics, TPC detectors have found profitable applications but their use in nuclear physics has been limited. With the ACTAR TPC design, individual detection pad sizes of 2 mm are the smallest ever attempted in either discipline but is a requirement for high-efficiency and high-resolution nuclear spectroscopy. The corresponding large number of electronic channels (16000 from a surface of only 25×25 cm) requires new developments in high-density electronics and data-acquisition systems that are not yet available in the nuclear physics domain. New experiments in regions of the nuclear chart that cannot be presently contemplated will become feasible with ACTAR TPC."