IVVS actuating system compatibility test to ITER gamma radiation conditions

• Published in: Fusion engineering and design 2013-10, Vol.88 (9-10), p.2084-2087
• Main Authors: Rossi, Paolo, Collibus, M. Ferri de, Florean, M., Monti, C., Mugnaini, G., Neri, C., Pillon, M., Pollastrone, F., Baccaro, S., Piegari, A., Damiani, C., Dubus, G.
• Format: Article
• Language: English
• Subjects: Design engineering; Gamma radiation; Gamma rays; IVVS; Laser beam; Piezo-motor; Piezoelectric motors; Remote handling; Space probes; Viewing; Walls
• ISSN: 0920-3796; 1873-7196
• DOI: 10.1016/j.fusengdes.2013.03.030

•ENEA developed and tested a prototype of a laser In Vessel Viewing and ranging System (IVVS) for ITER.•One piezo-motor prototype has been tested on the ENEA Calliope gamma irradiation facility to verify its compatibility to ITER gamma radiation conditions.•After a total dose of more than 4MGy the piezo-motor maintained almost the same working parameters monitored before test without any evident and significant degradation of functionality.•After the full gamma irradiation test, the same piezo-motor assembly will be tested with 14MeV neutrons irradiation using ENEA FNG facility. The In Vessel Viewing System (IVVS) is a fundamental remote handling equipment, which will be used to make a survey of the status of the blanket first wall and divertor plasma facing components. A design and testing activity is ongoing, in the framework of a Fusion for Energy (F4E) grant agreement, to make the IVVS probe design compatible with ITER operating conditions and in particular, but not only, with attention to neutrons and gammas fluxes and both space constraints and interfaces. The paper describes the testing activity performed on the customized piezoelectric motors and the main components of the actuating system of the IVVS probe with reference to ITER gamma radiation conditions. In particular the test is performed on the piezoelectric motor, optical encoder and small scale optical samples .The test is carried out on the ENEA Calliope gamma irradiation facility at ITER relevant gamma fields at rate of about 2.5kGy/h and doses of 4MGy. The paper reports in detail the setup arrangement of the test campaign in order to verify significant working capability of the IVVS actuating components and the results are shown in terms of functional performances and parameters. The overall test campaign on IVVS actuating system will be completed on other ENEA testing facilities in order to verify compatibility to Magnetic field, neutrons and thermal vacuum ITER typical environmental working conditions.