  Phonon-mediated particle detectors employing Kinetic Inductance Detectors
(KIDs) on Silicon substrates have demonstrated both O(10) eV energy resolution
and mm position resolution, making them strong candidates for instrumenting
next generation rare-event experiments such as in looking for dark matter or in
neutrino measurements. Previous work has demonstrated the performance of an
80-KID array on a Si wafer, however current energy resolution measurements show
a 25x difference between otherwise identical KIDs on the same wafer - between 5
to 125 eV on energy absorbed by the KID. Here, we use a first principles
approach and attempt to identify the drivers behind the resolution variation.
In particular, we analyze a subset of 8 KIDs using the unique approach of
pulsing neighboring KIDs to generate signals in the target. We tentatively
identify differences in quality factor terms as the likely culprit for the
observed variation.
