The Actar-TPC detector was optimized to study radioactive nuclei produced in small quantities. However, it is not simply a detector, since it is also acts as the gaseous target that the beam of nuclei is directed at, making it the very site of the nuclear reactions to be studied.

Projectile nuclei, such as the new particles produced during nuclear collisions, ionize the gas, generating electrons along their trajectories. At the end of their journey in the gas chamber, these electrons are collected and amplified. The signal that is generated makes it possible to reconstruct the 3D trajectories of particles in the approximately eight million voxels (volume elements) that make up the chamber, up to one hundred times per second. The 3D reconstruction of these trajectories makes it possible to identify and characterize the associated particles.

The low gas density of the chamber, its great depth and its 16,384 electron detection paths make the Actar-TPC a high-precision tool for elucidating nuclear reaction mechanisms as well as the structure of the nucleus, by analyzing all of the reaction products.

In November 2017, the Actar-TPC successfully passed its tests under the Ganil's beams and will now be used in the 2018 experimental program.