During the 60’s a new kind of radioactivity was predicted by V.I. Goldanski. To observe and characterize this 2 protons radioactivity we have built a TPC detector. A huge work on R&D was done to achieve this project. It’s only recently that the first observation of this radioactivity was done by à CENGB group. This king of detector allowing a three dimensional particles tracking more information about this radioactivity was collected (reaction energy, relative angle...). This detector is one of the first to use GEM (Gas electron multiplier) in the field of nuclear physics, the GEMs were originally developed for high energy particles physics detectors at CERN. This detector was develop on the request of the Exotic Nuclei group. More recently the TPC has been used at the local facility AIFIRA to measure the differential cross section of the elastic scattering of neutron on deuterium.