[en] The statistical method is used to analyze the asymmetric error field resulting from misalignment of PF and TF coils in EAST. The results show that the critical error field is beyond the scope of the physical requirement, so a set of correction coils should be designed to compensate the error field of the device. (authors)

[en] Highlights: • The eddy current of CFETR vacuum vessel can be calculated by using a series of ideal current loops. • The shielding effect with different eddy current is studied by decomposing the exciting magnetic field as two orthogonal components. • The shielding effect can be determined from the rate of eddy current magnetic field to the external magnetic field. - Abstract: The operation of superconducting magnet for fusion device is under the complex magnetic field condition, which affect the stabilization of superconductor. The coil-case of TF coil can shield the magnetic field to some extent. The shielding effect is related to the eddy current of coil-case. The shielding effect with different eddy current is studied by decomposing the exciting magnetic field as two orthogonal components, respectively. The results indicate that the shielding effect of CFETR TF coil-case has obvious different with the different directional magnetic field, and it’s larger for tangential magnetic compared with that for normal field.

[en] Highlights: • A multi-scenario force-calculating simulator for Tokamak magnet system is developed using interaction matrix method. • The simulator is applied to EM analysis of CFETR and EAST magnet system. • The EM loads on CFETR magnet coils at different typical scenarios and the EM loads acting on magnet system of EAST as function of time for different shots are analyzed with the simulator. • Results indicate that the approach can be conveniently used for multi-scenario and real-time EM analysis of Tokamak magnet system. - Abstract: A technology for electromagnetic (EM) analysis of the current-carrying components in tokamaks has been proposed recently (Rozov, 2013; Rozov and Alekseev, 2015). According to this method, the EM loads can be obtained by a linear transform of given currents using the pre-computed interaction matrix. Based on this technology, a multi-scenario force-calculating simulator for Tokamak magnet system is developed using Fortran programming in this paper. And the simulator is applied to EM analysis of China Fusion Engineering Test Reactor (CFETR) and Experimental Advanced Superconducting Tokamak (EAST) magnet system. The pre-computed EM interaction matrices of CFETR and EAST magnet system are implanted into the simulator, then the EM loads on CFETR magnet coils at different typical scenarios are evaluated with the simulator, and the comparison of the results with ANSYS method results validates the efficiency and accuracy of the method. Using the simulator, the EM loads acting on magnet system of EAST as function of time for different shots are further analyzed, and results indicate that the approach can be conveniently used for the real-time EM analysis of Tokamak magnet system.

[en] Highlights: • The eddy current distribution and variation of CFETR vacuum vessel during plasma disruption have been calculated. • Effective electrical parameters can be derived from the eddy current characters. • The method for eddy current and effective electrical parameters is suit for the complex shell with arbitrary shape. - Abstract: The electrical parameters of CFETR (China Fusion Engineering Test Reactor) vacuum vessel are very important to the design of control system and power supply system. Effective electrical parameters are relevant to the dynamic of eddy current. For complex structure, the distribution of eddy current can’t be obtained by analytical form. A method is presented to solve the eddy current of the vacuum vessel in this paper. The effective electrical parameters can be got from the eddy current distribution and variation. The time constant of the CFETR vacuum vessel is derived from the decay characteristics of the eddy current. And the effective resistance and inductance can be derived from the viewpoint of energy for a certain distribution of eddy current.

[en] Highlights: • A new technology–interaction matrix method is applied to assess EM loads of EAST magnet system. • The interaction matrices of EAST magnet system are obtained. • The application validated the efficiency and accuracy of the method. • Results indicate that the approach can be conveniently used for multi-scenario EM loads assessment for EAST current-carrying components. - Abstract: An approach for assessing the electromagnetic (EM) loads of the main current-carrying components in tokamaks has been proposed recently [1,2]. It is mainly based on the interaction matrix and the method is general. This paper explores on the application of the new technology to EAST magnet system. Firstly, the interaction matrices of EAST magnet composed of bilateral interaction forces between separate components at unit current are calculated, then the EM loads are obtained by a linear transform of given currents using the interaction matrix. The application validated the efficiency and accuracy of the method, which is useful for the systematic assessment of Tokamak EM forces. Results indicate that the approach can be conveniently used for multi-scenario EM assessments and parametric studies of the EM loads for EAST current-carrying components, and a specialized force-calculating module for real-time simulating will be developed in the future.

[en] A new quantum double is established from a new Hopf algebra and a new kind of quantum R-matrix is obtained. (orig.)

[en] Highlights: • The electromagnetic and structural responses of VV and PFCs for EAST are analyzed. • A detailed finite element model of the VV including PFCs is established. • The two most dangerous scenarios, major disruptions and downward VDEs are considered. • The distribution patterns of eddy currents, EMFs and torques on PFCs are analyzed. -- Abstract: During plasma disruptions, time-varying eddy currents are induced in the vacuum vessel (VV) and Plasma Facing Components (PFCs) of EAST. Additionally, halo currents flow partly through these structures during the vertical displacement events (VDEs). Under the high magnetic field circumstances, the resulting electromagnetic forces (EMFs) and torques are large. In this paper, eddy currents and EMFs on EAST VV, PFCs and their supports are calculated by analytical and numerical methods. ANSYS software is employed to evaluate eddy currents on VV, PFCs and their structural responses. To learn the electromagnetic and structural response of the whole structure more accurately, a detailed finite element model is established. The two most dangerous scenarios, major disruptions and downward VDEs, are examined. It is found that distribution patterns of eddy currents for various PFCs differ greatly, therefore resulting in different EMFs and torques. It can be seen that for certain PFCs the transient reaction force are severe. Results obtained here may set up a preliminary foundation for the future dynamic response research of EAST VV and PFCs which will provide a theoretical basis for the future engineering design of tokamak devices

[en] The authors reviews a new protocol of quantum memory based on the quasi-pin wave excitation of the Λ systems fixed the sites of lattice. This protocol tries to avoid the disadvantage of the quantum memory scheme based on free atom ensemble, the quantum decoherence induced by the quantum leakage of collective state. Especially, authors discover a universal dynamic symmetry hidden in various ensemble based quantum storage scheme. To understand the significance of this work exactly, authors also give a brief introduction to our systematical studies on collective symmetric excitons in quantum ensemble, which is the necessary to propose the present scheme for quantum memory. (author)

[en] The design parameter, electromagnetic and water-cooling analysis and fabrication process of EAST active feedback control coils are presented. As the diagonal leaders suffer huge vertical force variation, conventional organic insulating material cannot meet the requirements. Magnesium oxide was used as insulating material and supports were added to both ends of the diagonal leaders. Water-cooling calculations show that the temperature of the copper conductor and water is linearly related to the distance from the point to the water inlet. In order to assure the temperature of outlet water not be heated to boil, the relation of the minimum velocity of water and operation ratio is about v ≈ 6 K when the current in the coil is 20 kA. (authors)

[en] Optical instruments integrating with machine template is used to align the assembly of EAST in-vessel components. The measure benchmarks of in-vessel components are introduced by the benchmark holes on the template. The final aspect of the first wall is calibrated to the accurate position by another special template. (authors)