Thought experiment

[bsaucer]

If I let the "source" be an unstable particle (or nucleus), which, when it decays, emits a small particle, and I set up an apparatus which directs this moving particle along two or more paths to the target, and I adjust the lengths of these paths so that the wave function of the particle destructively interferes at the target, so that it never actually reaches the target, can this prevent the source particle (or nucleus) from decaying, thus making it stable?

Is this a delayed choice paradox?

[Cubola Zaruka]

A particle's position and velocity cannot both be determined, so it is not possible to create such paths of the right lengths and the moment at which the particle decays remains unpredictable.