Background due to stored electrons following nuclear decays in the KATRIN spectrometers and its impact on the neutrino mass sensitivity

Abstract

The KATRIN experiment is designed to measure the absolute neutrino mass scale with a sensitivity of 200 meV at 90% C.L. by high resolution tritium beta-spectroscopy. A low background level of 10 mHz at the beta-decay endpoint is required in order to achieve the design sensitivity. In this paper we discuss a novel background source arising from magnetically trapped keV electrons in electrostatic retarding spectrometers. The main sources of these electrons are alpha-decays of the radon isotopes (219,220)Rn as well as beta-decays of tritium in the volume of the spectrometers. We characterize the expected background signal by extensive MC simulations and investigate the impact on the KATRIN neutrino mass sensitivity. From these results we refine design parameters for the spectrometer vacuum system and propose active background reduction methods to meet the stringent design limits for the overall background rate.

References in corpus (3)

• The KATRIN Pre-Spectrometer at reduced Filter Energy
• Validation of a model for Radon-induced background processes in electrostatic spectrometers
• Stochastic Heating by ECR as a Novel Means of Background Reduction in the KATRIN Spectrometers

Cited by in corpus (15)

• Current Direct Neutrino Mass Experiments
• Direct Measurements of Neutrino Mass
• The Design, Construction, and Commissioning of the KATRIN Experiment
• Kassiopeia: A Modern, Extensible C++ Particle Tracking Package
• KATRIN: Status and Prospects for the Neutrino Mass and Beyond
• First operation of the KATRIN experiment with tritium
• Direct Neutrino Mass Experiments
• Neutrino mass sensitivity by MAC-E-Filter based time-of-flight spectroscopy with the example of KATRIN
• Neutrino Masses
• Technical design and commissioning of the KATRIN large-volume air coil system
• Modeling of electron emission processes accompanying Radon-$\alpha$-decays within electrostatic spectrometers
• Validation of a model for Radon-induced background processes in electrostatic spectrometers
• Search for Lorentz-Invariance Violation with the first KATRIN data
• Stochastic Heating by ECR as a Novel Means of Background Reduction in the KATRIN Spectrometers
• Reduction of stored-particle background by a magnetic pulse method at the KATRIN experiment