1350+ Days of Tritium Operation Experience of KATRIN at Tritium Laboratory Karlsruhe

The KArlsruhe TRitium Neutrino (KATRIN) experiment aims to determine the effective mass of the electron antineutrino by investigating the tritium β-spectrum close to the kinematic end point. The Tritium Laboratory Karlsruhe hosts and operates the tritium parts of the experiment. A dedicated tritium loop system is tasked to provide the <0.1% stabilized flow rate of tritium gas into the KATRIN source, maintaining a throughput of 40 gd$^{−1}$ and a tritium purity >95%, while at the same time acting as the interface to the established tritium handling infrastructure of the laboratory, reliably working for more than 3 decades. Since KATRIN’s start of tritium operation in May 2018, more than 1350 operation days of the tritium “loop” system combined with KATRIN’s tritium source have been achieved. This paper summarizes the tritium operation experience gained with special emphasis on the permeator performance, a key component enabling direct internal recycling.