[AlexanderHowl]

Neutron bombardment of lithium produces tritium, which decays into helium-3, which is why you have helium-3 in lithium deposits. This is the entire process behind tritium breeding (and the majority of helium-3 production comes from tritium decay). In general though, if you have mastered D-He-3 fusion, it makes more sense to just create He-3 through D-D fusion than to attempt tritium breeding.