Implementation of the Gas Management System for the ELI-NP Mini-electronic Time Projection Chamber

The Mini-electronic Time Projection Chamber (Mini-eTPC) of ELI-NP is a state-of-the-art gaseous target detector whose primary application consists in studying reactions relevant to the field of nuclear astrophysics. A key element toward ensuring the optimal functionality of the Mini-eTPC is its associated Gas Management System (GMS), which allows the target gas to be recirculated through the active volume with a high degree of pressure stability over time and adequate purification to ensure minimal chances of contamination. The configuration and functionality of the GMS components are presented herein in turn, along with the reasoning that led to the specific design choices behind their implementation and the tests we performed to ensure their optimal functionality. Our results show that the GMS can provide stability levels within ± 0.01 mbar(a) of the required working pressure over almost 200 h of continuous operation, meaning that the Mini-eTPC can be confidently used to perform extended astrophysics studies while purifying and recovering the target gas instead of venting it. Looking ahead, we plan to upscale the GMS design to create a separate gas system to serve the larger ELI-TPC that will become a key setup of our facility in the near future.