We present the design, construction, and first experimental results of a gaseous optical Time Projection Chamber (TPC). Gaseous detectors are excellent candidates for neutrino physics, where the largest source of systematic uncertainties is given by not being able to detect low-momentum protons, such as the ones produced in multinucleon neutrino interactions. The present TPC is operated with argon gas at atmospheric pressure and 20 degrees C, based on a Thick Gaseous Electron Multiplier (ThGEM), where primary electrons are multiplied, and light is produced simultaneously.

The TPC is a 20-litre stainless-steel cylindrical chamber, sealed with two flanges: one fitted with electrical connectors and the other with a transparent window through which photons can leave the chamber. The active volume of the TPC is placed on a frame constructed from low-outgassing materials, carefully chosen to preserve the chamber’s high purity. The TPC is equipped with two different readouts. The first is a Photomultiplier Tube (PMT), which is replaced with an SiPM array towards the final stages of the project.