Californium is a radioactive transuranium element produced by bombarding curium with helium ions. It is the heaviest weighable element. The homologue of californium is dysprosium.
Californium News 2013-02-28 - (ornl) - ORNL begins implementation of new californium-252 production contract
2010-04-13 - (po) - Argonne's CARIBU charge breeder breaks world record for effficiency