A Liquid-Tritium Target for Studying ptμ-Fusion Reactions

A cryogenic liquid-tritium target was developed by RFNC−VNIIEF for studying ptμ fusion. In 2016, it was regularly used for more than 270 h on the muon channel of the JINR Phasotron, thus confirming the compliance with the specified requirements and the correctness of the proposed engineering solutions. At a maximum operating pressure of 4 MPa, an irradiated ampoule volume as large as 80 cm3, and three lines of protection, the target was able to liquefy up to 40 L of a hydrogen-isotope mixture and maintain a temperature in the range of 20−22 K with an accuracy of ±0.05 K or better. Based on the results of the ptμ‑fusion experiments, the reaction channel with the emission of electron−positron pairs was detected for the first time and evidence for the existence of a new reaction channel with the emission of a pair of γ-ray photons was obtained.