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Abstract: The ITER Heating Neutral Beam injectors will be implemented in three steps: development of the ion source prototype, development of the full injector prototype, and, finally, construction of up to three ITER injectors. The first two steps will be carried out in the ITER neutral beam test facility under construction in Italy. The ion source prototype, referred to as SPIDER, which is currently in the development phase, is a complex experiment involving more than 20 plant units and operating with beam-on pulses lasting up to 1h. As for control and data acquisition it requires fast and slow control (cycle time around 0.1ms and 10ms, respectively), synchronization (10ns resolution), and data acquisition for about 1000 channels (analogue and images) with sampling frequencies up to tens of MS/s, data throughput up to 200MB/s, and data storage volume of up to tens of TB/year. The paper describes the architecture of the SPIDER control and data acquisition system, discussing the SPIDER requirements and the ITER CODAC interfaces and specifications for plant system instrumentation and control. [Copyright &y& Elsevier]

Abstract: In the framework of the construction of the Test Facility for the ITER Neutral Beam Injector to be installed at Consorzio RFX in Padova (Italy), a cryosorption cryopump, designed by FZK, will be employed to guarantee the appropriate pressure range for the D2or H2 pulsed beam. The cryopanels that constitute the cryopump will be indirectly cooled by means of supercritical helium at temperatures ranging from 4.5K to 6.5K and at a pressure of 0.5MPa. The thermal shields will be indirectly cooled by means of high pressure (1.5MPa) gas helium at temperatures from 65K to 90K. In order to provide the helium gas and the supercritical helium to the cryopump, a cryogenic plant has been further designed by RFX. The cryogenic plant consists of a Main Refrigerator to supply the supercritical helium, a Shield Refrigerator based on a Brayton cycle for the cooling of thermal shields, a Proximity Cryogenic System to provide the helium distribution and a Helium Recovery and Purification System to deliver pure helium to the refrigerators. The plant has been conceived to operate in several functioning modes according to the needs of the test facility: a cool-down operation, stand-by and NBI operation modes, a 100K regeneration mode, a warm up operation to ambient temperature, and a 470K regeneration mode. The full flexibility of the system has been pursued to assure its reliability and to chase unbroken operation. This paper presents the cryoplant design and the technical solutions adopted to optimize the system performances and its capability to implement all the required operative scenarios in a fully automatic mode. [Copyright &y& Elsevier]