Search

The ITER Central Solenoid (CS) is under fabrication by the US ITER organization and its subcontractors. US ITER will supply seven modules to ITER IO, six of which will be assembled in a stack that forms the ITER Central Solenoid, with one as a spare. The first module fabrication has been completed by General Atomics (GA) at their facility and has begun testing including high voltage testing, Paschen testing in the vacuum and then testing at 4.5 K and up to 40 kA in order to demonstrate compliance of the coil to ITER requirements. In the paper we present the Test Plan and results of the CS Module performance tests, especially at 40 kA current. AC losses, joint resistances and hydraulic characteristics of the coil are all measured. Displacements of the coil height and hoop strain of the CS Module are also measured to verify structural and mechanical characteristics of the coil along with cooldown shrinkage of the coil. This information is used for verification of the stack behavior of CS in ITER operation. The test results and preliminary analyses results are presented, compared to expectations, and discussed. All measured parameters suggest that the CS module will perform well in ITER machine. [ABSTRACT FROM AUTHOR]

The Central Solenoid (CS) is a key element of the ITER Magnet system, including six identical coils, called modules, assembled together to form a 4 m outer diameter, 13 m high solenoid. It is a superconducting magnet, with a peak field up to 13 T. The magnet is enclosed inside a steel structure providing vertical pre-compression and mechanical support. The room temperature pre-compression load is necessary to prevent displacement and gap between coils during the exploitation phase and therefore reduce the CS performance and create mechanical stress. The target CS pre-compression is 210 MN realized by the tightening of 45 Multi Jack Tensioners (MJTs) divided in 9 sectors. Procurement of the components and the procedures of the ITER CS is the responsibility of the USA Domestic Agency (USDA), while the ITER Organization (IO) will carry out the assembly of these components. IO signed in 2018 a collaboration agreement with CEA/IRFM to implement the pre-compression procedure proposed by the USDA using a dedicated mock-up with the main objectives: - Simulating the all modules stack rigidity with Spring plates; - Characterize the young's modulus of one CS section module; - Validating the technical procedures proposed - Estimating the time impact to accomplish the CS pre-compression process in accordance to the complete ITER Tokamak assembly. The CS mock-up Pre-compression Verification (CSPV) uses a 1/9 segment of the overall CS with a mix of ITER Tokamak and mock-up components. The target load of the mock-up is 23.3 MN to be in accordance with the overall CS pre-compression load value. This paper presents the CSPV mock-up activities, the challenges encountered and the results gained. As a conclusion, the tightening process is highlighted to estimate its applicability for the ITER CS assembly in term of technical and organisational aspects. The views and opinions expressed herein do not necessarily reflect those of the ITER Organization. [ABSTRACT FROM AUTHOR]

Abstract: The National Compact Stellarator Experiment (NCSX) has been under construction at the Princeton Plasma Physics Laboratory (PPPL) in partnership with the Oak Ridge National Laboratory (ORNL). The stellarator core is designed to produce a compact 3D plasma that combines stellarator and tokamak physics advantages. The complex geometry and tight fabrication tolerances of NCSX create some unique engineering and assembly challenges. The NCSX project was cancelled in May 2008; construction activities are presently being phased out in an orderly fashion. This paper will describe the progress of the fabrication and assembly activities of NCSX. Completion of the coil fabrication is on track for the summer of 2008. All three of the vacuum vessel 120° sections have been delivered. Assembly of vacuum vessel services began in May 2006 and is now complete. Assembly of the modular coils into 3-packs for safe storage is presently underway. [Copyright &y& Elsevier]