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The W -for tungsten- environment in steady-state tokamak (WEST) project consists in transforming the French tokamak Tore Supra into an X-point divertor one and aims at testing the ITER technology of actively cooled high heat flux tungsten components during ITER-relevant long pulses. In addition to the integration in the vacuum vessel of a lower divertor and an upper one, this metamorphosis has a strong impact on diagnostics initially present in Tore Supra. Indeed, the introduction of a divertor in the upper part of the machine leads to block the lines of sight (LOS) of diagnostics previously installed in the upper ports. Therefore, new diagnostics playing a paramount role for the safe tokamak operation need to be implemented, such as an infrared (IR) thermography diagnostic for the protection of plasma-facing components (PFCs) and heating antennas, and a visible spectroscopy system for the protection of tungsten PFCs. Besides, several existing diagnostics need to be modified to adapt their LOS to the new divertor targets and plasma shape. This paper presents the main issues linked to the integration of diagnostics deriving from the WEST project. First, the changes involved by the upgrade on the set of diagnostics currently implemented in Tore Supra are described. Then, a particular focus is put on the integration of the two new optical systems, namely the IR system and the visible spectroscopy one. These two systems being located within the vacuum vessel, a special care must be paid to their design, to allow them to withstand their harsh environmental conditions. Other new or updated fundamental diagnostics are also briefly presented. Finally, the resulting new implementation of diagnostics envisaged to reach the scientific and technological goals of the WEST project is described. [ABSTRACT FROM PUBLISHER]

Abstract: Diagnostics in ITER are mandatory to characterize the parameters of plasma and study its interactions with plasma-facing components. Diagnostics components in the vicinity of the plasma are supported by metallic structures called port plugs. At the tokamak mid-plane, these components are installed in port plugs through intermediate structures called drawers. Apart from hosting the diagnostics, the port plugs act as shielding against neutrons and gammas, in order to limit the nuclear loads in crucial components (such as diagnostics and superconducting coils) as well as the dose levels in the controlled zones of the tokamak. The radiation shielding function of the port plugs is ensured through an optimized mixture of heavy metallic materials and water, forming shielding blocks surrounding the diagnostics and called Diagnostic Shield Modules (DSMs). These DSMs constitute the rear part of the drawers (the front part being composed of the Diagnostic First Wall). This paper presents the main results of a study performed in Europe on the integration of a particular diagnostics port plug, the Equatorial Port Plug 1 (EPP1). The paper first provides the results of the EPP1 diagnostics integration analysis. In a second step it focuses on the design of the EPP1 DSMs and summarizes the major results of a thorough set of analyses aiming at studying the DSMs behaviour under different loads, suggesting recommendations to improve their current design. [Copyright &y& Elsevier]

Diagnostics in International Thermonuclear Experimental Reactor (ITER) are supported by big structures called port plugs, the second main function of which is to ensure a sufficient shielding against neutrons and gammas. Regarding the integration of diagnostics in equatorial port plugs, a new approach is under study, which consists in installing the diagnostics in “drawers”. This paper describes the recent work which has been performed in Europe on the integration of diagnostics in drawers in the Equatorial Port Plug 1 (EPP1). First, the methodology which has been followed to progress on the integration of the diagnostics in this port plug is described, and the resulting arrangement of diagnostics is shown. Then, a special attention is paid to the integration of the two main diagnostics of EPP1, namely the visible/infrared wide angle viewing system and the radial neutron camera. Finally, the preliminary design of the drawers of EPP1, in particular the shielding modules around the diagnostics, is presented, and the preliminary results of the analyses performed to validate this design are provided. [ABSTRACT FROM PUBLISHER]

Abstract: The exploitation of ITER tokamak will require diagnostics for machine protection, inputs to plasma control systems, evaluation and analysis of plasma parameters and performances. The equatorial visible/infrared wide angle viewing system and the radial neutron camera are the two main diagnostics of Procurement Package 11 (PP11), one of the diagnostic procurements under the responsibility of Europe, which also contains Equatorial Port Plug 1 and seven other diagnostics supplied by Europe or other ITER partners and integrated in the same Port Plug. Significant progress has recently been made in the development of the equatorial visible/infrared wide angle viewing system and the radial neutron camera. This paper gives an overview of the major technical achievements on these two diagnostics and points out the urgent needed R&D activities. [Copyright &y& Elsevier]

The WEST project (W-Environment in Steady-State Tokamak) aims to transform the Tore Supra limiter configuration to an x-point divertor, providing a test bed for ITER-like plasma-facing components (actively cooled W monoblocs) under high heat flux, steady-state plasma irradiation. The lower divertor includes an actively cooled, W-coated CuCrZr baffle to provide neutral compression and improve particle exhaust. As part of the new diagnostic equipment of Tore Supra within WEST project, a set of Langmuir probes will find place on the baffle in order to provide plasma flux and electron temperature measurements for physics studies and real-time machine protection functions during steady-state discharges. On the baffle top surface, irradiation coming from the plasma, energetic ripple-ions losses, photons and energetic neutrals from charge exchange reactions produce power fluxes up to 3 MW/m 2 , representing a challenge for the Langmuir probes operating conditions. In this paper Copper–Chrome–Zirconium (CuCrZr) cylindrical probe concept design is proposed. Finite element thermo-mechanical analysis (FEA) confirmed the consistency of this solution under the steady-state plasma condition in the worst case (highest thermal load). [ABSTRACT FROM AUTHOR]