Status of the Magnets of the Two Tritium Pumping Sections for KATRIN

Abstract

The next generation neutrino mass experiment KATRIN (Karlsruhe Tritium Neutrino experiment) uses a series of superconducting magnet systems, which guide the electrons from tritium beta-decay adiabatically from the source to the detector within a magnetic flux of 0.0191 . The electron transport and tritiuAm pumping sections contain two complex magnet systems; the Differential Pumping Section (DPS2-F) and the Cryogenic Pumping Section (CPS) that are designed with a central magnetic flux density from 5 T to 5.7 T for persistent-mode operation. Each system has a series of superconducting solenoids in a zigzag arrangement that is designed to enhance the tritium pumping efficiency. The 7 m long DPS2-F was commissioned at the end of 2010 and the magnetic performance of the DPS2-F was accepted for the KATRIN experiment. The DPS2-F was operated for more than 325 hours in persistent-mode to investigate long term field stability, which is required to stay within 0.01% at the nominal field for a 60-day measurement run. All seven modules of the CPS were manufactured and successfully cold-tested.