Phi-sparker
A phi-sparker is a sparker that emits phi sparks. These are desirable because phi sparks have uses, for example reflecting gliders.
This is the mechanism by which a single pentadecathlon can reflect a glider, such as in the p60 glider shuttle. However, while the pentadecathlon provides a T-nosed spark followed by a V spark in the same manner as a phi spark, not all interactions with a phi spark would work with a pentadecathlon (at least not without destroying the pentadecathlon), so the pentadecathlon is only a moderate phi-sparker. An example of a strong phi-sparker is Tanner's p46. Like other phi-sparkers, it can reflect gliders.
However, it can also engage in interactions that perturb a phi spark in a way that would destroy a pentadecathlon, such as in the p46 gliderless MWSS gun.