  The Beta-decay Paul Trap is an open-geometry, linear trap used to measure the
decays of $^8$Li and $^8$B to search for a tensor contribution to the weak
interaction. In the latest $^8$Li measurement of Burkey et al. (2022), $\beta$
scattering was the dominant experimental systematic uncertainty. The Beta-decay
Paul Trap Mk IV reduces the prevalence of $\beta$ scattering by a factor of 4
through a redesigned electrode geometry and the use of glassy carbon and
graphite as electrode materials. The trap has been constructed and successfully
commissioned with $^8$Li in a new data campaign that collected 2.6 million
triple coincidence events, an increase in statistics by 30% with 4 times less
$\beta$ scattering compared to the previous $^8$Li data set.
