Temperature monitoring of the FUTURIX MI irradiation experiment in PHENIX

Experimental capsules irradiated in the fast neutron reactor Phenix could not be instrumented with classical thermocouples to monitor the internal temperature of materials during irradiation. Thereby two different types of passive temperature monitors were designed to determine the maximal temperature reached inside an irradiation experiment of inert materials in Phenix called FUTURIX MI. These two passive monitors consist in 1) several fuses of pure metal or metallic alloys processing well known melting points, 2) SiC specimens for which the swelling caused by irradiation damages is directly linked to the operating temperature. The FUTURIX MI experiment equipped with these passive monitors, has been loaded in the reactor on May 2007 and removed on March 2009, after a 235 Equivalent Full Power Days (EFPD) irradiation. The technologies used to elaborate the temperature monitor are depicted in this paper.