29th Symposium on Fusion Technology (SOFT 2016)

O3A.4 System level design of the ITER Equatorial visible/infrared Wide Angle Viewing System

6 Sep 2016, 17:40

20m

Congress Hall 2nd floor (Prague Congress Centre)

Board: 4

Oral D. Diagnostics, Data Acquisition and Remote Participation O3A

Speaker

Laurent Letellier (IRFM)

Description

The equatorial visible infrared wide angle viewing system (WAVS) is one of the key diagnostics in ITER aiming at the machine protection and plasma control. Those two main functions are achieved by means of infrared thermography and visible observation of the main plasma facing components. The diagnostic is composed of 15 lines of sight integrated in 4 equatorial port plugs allowing coverage of about 80% of the vacuum vessel. This diagnostic will be composed of 30 optical systems distributed under vacuum in the equatorial Port Plug and in air in the Interspace, in the Port Cell and in the diagnostic building. The data generated by the cameras will be processed and transferred among others to the Plasma Control System for real time control. Prior to the start of the design of such a complex system, a system level design (SLD) has been performed aiming at the identification of the requirements, the definition of the sub-systems and their functions, the location of the different components and the identification of the interfaces. The first phase of the SLD gathered the requirements. From the analysis of the project documentation, requirements applicable to the WAVS have been identified and implemented in a standard framework, allowing traceability of the requirements and their evolution during the project life. During a second phase, based on a functional analysis, translating requirements into functions from highest level (functional) down to components (technical), different architecture options have been produced. Compared to the initial architecture, alternatives are proposed in three areas: Port plug (substitution of the on-axis Cassegrain by an off-axis Gregorian telescope, a-focal optical interface), Interspace (suppression of refractive optics and Cassegrain telescopes) and Port Cell (separation of IR-Vis). The paper will present the details of the system level design approach for the WAVS project and the new architecture proposals.