I believe the neutron decays with a half life around 12 minutes via the weak mechanism. I'm wondering what causes a particular neutron to decay. At the moment the neutron decays, has it encountered (run into) a stray weak field? Or ... does the neutron decay just because of internal forces? If we could build something like a Faraday cage that would keep out the weak force, then would a neutron inside that Faraday cage decay?