  The KATRIN experiment aims to determine the effective electron neutrino mass
with a sensitivity of $0.2\,{\text{eV}/c^2}$ (90\% C.L.) by precision
measurement of the shape of the tritium \textbeta-spectrum in the endpoint
region. The energy analysis of the decay electrons is achieved by a MAC-E
filter spectrometer. A common background source in this setup is the decay of
short-lived isotopes, such as $\textsuperscript{219}$Rn and
$\textsuperscript{220}$Rn, in the spectrometer volume. Active and passive
countermeasures have been implemented and tested at the KATRIN main
spectrometer. One of these is the magnetic pulse method, which employs the
existing air coil system to reduce the magnetic guiding field in the
spectrometer on a short timescale in order to remove low- and high-energy
stored electrons. Here we describe the working principle of this method and
present results from commissioning measurements at the main spectrometer.
Simulations with the particle-tracking software Kassiopeia were carried out to
gain a detailed understanding of the electron storage conditions and removal
processes.
