  Purcell effect predicts that spontaneous radiation is not an intrinsic
property of matter, but is affected by the environment in which it is located,
and is the result of the interaction of matter and field. Purcell effect can be
inferred from Fermi Gold rule through strict quantum electrodynamics (QED), and
through it can achieve the enhancement or suppression of radiation. We suggest
that, in principle, the Purcell effect can be detected at the percentage level
of neutron decay in experiments with trapped ultra-cold neutrons. As a test of
our claim, we propose a currently achievable experimental protocol that can
detect whether Purcell effect has occurred in an trapped ultra-cold neutron
lifetime measurement experiment. Finally, we discuss the discrepancy in current
methods of measuring neutron lifetime, which may be caused by different
experimental setups.
