FE Stress Analysis of the Toroidal Field Magnets of HT-7U

1. IntroductionAs a full-superconducting tokomak, the HT－7Udevice is an advanced steady-state plamsa physicsdevice, which produces 3.5 T toroldal field (centralfield) at the plasma major radius of 1.7 m and about5.8 T peak field at the TF coils with the ripple of lessthan 1% within the range of plasma [11. The toroidalfield magnet system is one of the important parts ofHT-7U superconducting tokamak. This system consists of toroidal arrayed sixteen coils which spaced22.5' apart, and are sy…     

The Analysis and Calculation for the Toroidal Magnetic Field of HT-7U

1. IlltroductionThe HT--7U device is a large noncircular cross section super--conducting tokamak to be built in 2003.It will have a long pulse (60 ~ 1000 s) capability, aflexible PF system, and auxiliary heating and current driving sXstemsl and will be able to accommodate divertor heat loads that make 'it an attractivetest for the development of advanced tokamak operating modes [l]. The overview structure of theHT--7U tokamak is shown in Fig.1. Its toroidalfield system is one of important …     

Preliminary Engineering Design of Toroidal Field Magnet System for Superconducting Tokamak HT-7U

1.IntroductionHT-7Usuperconductingtokamakisanationalsci-entificresearchprojectofChina.ThislargefusionexperimentaldevicewillbebuiltinthelnstituteofPlasmaPhyslcsofChineseAcademyofSciences.ThemissionofHT-7Uistodevelopthescientificba-sisforacontinuouslyoperatingtokamakfusionreac-tor,achievingasteadystateandanextremelylongpuIseoperatlonwlthhigh-betadouble-null,aswellassingle-nullplasmasatfllllcllrrent.HT-7Uisafullsuperconductingtokamakdevlce.ltstoroidalfieldsystemisoneoftheimportantpartsofthe…     

A Study on Main Breaker for Quench Protection of HT-7U Toroidal Superconducting Tokamak

This paper proposes a quench protection project of HT-7U toroidal superconductingtokamak through a forced commutation analysis of DC circuit breaker (DCCB) paralleling fuse.Based on the requirement of quench protection, main parameters are selected. Experimentalresults demonstrate the validity of this proposed project.     

Design of the Magnetic Field for HT-7U Tokamak

1. Main parameters ofHT-7U deviceThe scientific cession of the HT－7U(HefeiTOkamak-7 Upgrade ), being a next generation advanced tokamak, is to study physical issues on thesteady-state operation of a non-burning plasma. The'. -.engineering mission of the HT-7U tokamak is to establish the technology basis of full superconductingtokamaks for the future reactor. The HT-7U toka-mak will have a long pulse (60 ~ 1000 s ) capability,a flexible PF system, an auxiliary heating and current drive …     

The Experiment of Modulated Toroidal Current on HT-7 and HT-6M Tokamak

The Experiments of Modulated Toroidal Current were done on the HT-6M tokamak and HT-7 superconducting tokamak. The toroidal current was modulated by programming the Ohmic heating field. Modulation of the plasma current has been used successfully to suppress MHD activity in discharges near the density limit where large MHD m = 2 tearing modes were suppressed by sufficiently large plasma current oscillations. The improved Ohmic confinement phase was observed during modulating toroidal current (MTC) on the Hefei Tokamak-6M (HT-6M) and Hefei superconducting Tokamak-7 (HT-7). A toroidal frequency-modulated current, induced by a modulated loop voltage, was added on the plasma equilibrium current. The ratio of A.C. amplitude of plasma current to the main plasma current △Ip/Ip is about 12% ～ 30%. The different formats of the frequency-modulated toroidal current were compared.     

Poloidal Field Control for the HT—7U Superconducting Tokamak

Controlling the poloidal field(PF) in the HT-7U superconducting tokamak is critical to the realization of the mission of advanced tokamak research.Plasma start-up,plasma position,shape,current control and plasma shape reconstruction have been performed as a part of its design process.The PF coils have been designed to produce a wide range of plasmas,Plasma start-up can be achieved for multiple conditions.Fast controlling coils for plasma position inside the vacuum vessel are sued for controloling the plasma vertical position on a short timescale.The PF coils control the plasma current and shape on a slower timescale,VXI(VME bus extensions for Instrumentation)Bus system and DSP(Digital Signal Processor is a basic unit of the feedback control system),the response time of which is about(2-4)ms.The basic unit of this system ,the shape-controlling algorithms of a few critical points on plasma boundary and real-time equilibrium fitting(RTEFIT)will be described in this paper.     

Simulation Study of Heat Flux Deposition Pattern on the Surface of HT-7 Toroidal Limiters

The heat flux deposition pattern on the toroidal limiters installed in HT-7 was simulated with ANSYS code. The simulation model was established with the ripple of the magnetic field. The heat deposition pattern and temperature distribution on the surface of the toroidal linfiters were obtained. A comparison of the results obtained with and without the shaped tiles, used to reduce the heat flux on the leading edge of the limiters, was made. The maximum heat load allowed at the leading edge was about 1.8 MW/m2 because of the poor power removing capacity on the ends of the limiters. This approach can also be applied to other devices with a limiter configuration in a circular cross-section shape.     

Strain Measurement on the Toroidal Field （TF） Coil Cases

The stress-strain state of the structure is a matter of interest to designer. The strain measurement of superconducting magnets at cryogenic temperature is a specific technique. Based on strain measurement of TF coil case for EAST, this paper presents a measuring technique at cryogenic temperature and on intense magnetic field. The compensation methods for both temperature and magnetic field effects of the gauges, together with the measured results are involved, and the discussions of the measured results are given in the paper.     

The Circulating Current Analysis and Parameter Design of Interphase—Reactor of HT—7U Toroidal Power Supply

This paper analyzes the circulating current which is produced by HT-7U superconducting toroidal power supply-two sets of two-reverse-star converter with an interphase-reactor in parallel running on the basis of the output voltage mathematical equation of three-phaase semi-wave converter circuit.A new iden of omitting interphase-reactor between two converters is proposed,and the parameter design of interphase-reactor of HT-7 toroidal power supply is presented.Simulated results demonstrate the validity of this new project.     

Integrated Design System of Toroidal Field Coil for CFETR

Integrating engineering software is meaningful but challenging for a system code of a fusion device.This issue is seldom considered by system codes currently.Therefore,to discuss the issue,the Integrated Design System of TF Coil(IDS-TFC) has been worked out,which consists of physical calculation,CAD,and Finite Element Analysis(FEA).Furthermore,an Integrated and Automatically Optimized Method(IAOM) has been created to address the integration and interfaces.The method utilizes a geometry parameter to connect each design submodule and achieve automatic optimization.Double-objectives optimization has been realized,confirming it is feasible to integrate and optimize engineering design and physical calculation.Moreover,IDSTFC can also serve as a useful reference of integrated design processing for subsequent fusion design.     

Temperature Field and Thermal Stress Analysis of the HT-7U Vacuum Vessel

1.IntroductionHT-7UsuperconductingTokamakisanadvancedsteady-stateplasmaphysicsexperimentaldevice.ThedevicewillbebuiltattheinstituteofPlasmaPhysics,theChineseAcademyofSciencesintheyear2003.Itscessionistodevelopthescientific.basisandtechnologicbajsisforthefutureTokamakfusionreactorsandtostudyphysicalissuesonthesustenanceOfanon-burningplasmascenarioforthesteady-stateoperation.TheHT--7Uhasacapabilityforlongpulse(60-1000s)operation.Theprojecthasbeenapprovedandfundedasanationalmegscience-engin…     

A Lower Rigid Support Structure for the HT—7U Vacuum Vessel

Vacuum vessel of the HT-7U is a fully welded toroidal structure with a noncircularcross-section nested in the bore of the TF coils. According to the requirement of the physicsdesign, sixteen horizontal ports on outboard mid-plane and thirty-two vertical ports on the topand bottom are designed for diagnostics, plasma heating, current driving, vacuum pumping andgas puffing. Bellows on these port necks are used for flexible components to absorb the relativedisplacement in radial and vertical directions due to external load, thermal expansion or contrac-tion and assembly tolerance, and also used for isolation of mechanical vibration. For the supportsystem of vacuum vessel it should be not only strong enough to withstand forces acting on thevessel interior components and the vessel itself due to the dead weight and electromagnetic inter-actions during plasma disruption, but also sufficiently flexible to be suited to thermal expansionduring baking. In order to solve this contradiction a new kind of low rigid s     

Preliminary Design of Poloildal Field Power Supply for HT-7U Super-conducting Tokamak

1. IntroductionBeing distinct from other power supplies, poloidalfield power supply (PFPS) is the major part in powersupply system of HT--7U superconducting tokamak,with characteristics of hi$h current derivative, highpeak power, high power variation, and sophisticatedcontrol. The main function and task of PFPS are torealize the energy transfer and power conversion ofplasma initiation, maintenance, heating: and control(shape, position and disruption control) in experiment.Based on the main…     

Finite Element Analyses and Instrumentation Layout for Single Coil Testing of TF Coils in HT-7U

The HT-7U tokamak is a magnetically-confined full superconducting fusion device, consisting of superconducting toroidal field (TF) coils and superconducting poloidal field (PF) coils. These coils are wound with cable-in-conductor (CICC) which is based on UNK NbTi wires made in Russian '. A single D-shaped toroidal field magnet coil will be tested for large and expensive magnets systems before assembling them in the toroidal configuration. This paper describes the layout of the instrumentation for a superconducting test facility based on the results of a finite element modeling of the single coil of toroidal magnetic field (TF) coils in HT-7U tokamak device. At the same time, the design of coil support structure in the test facility is particularly discussed in some detail.     

核聚变实验装置HT-7U及大厅活化分析

使用一维ＳＮ离散坐标法输运程序ＡＮＩＳＮ、活化计算程序ＡＦＤＫＲ并使用一维球几何模型对ＨＴ－７Ｕ装置米要部件及混凝土屏蔽墙的活化进行了计算和分析,给出了中子能谱、γ能谱、大厅内外剂量率空间分布及放射性水平的时间分布,对ＨＴ－７Ｕ装置的主要中子学参数及周围居民接收剂量水平给出了定量的分析。     

Recent Progress of HT-7U Superconducting Tokamak

HT-7U is a superconducting tokamak. which is being constructed in Institute of Plasma Physics, Chinese Academy of Sciences. The mission of the HT-7U project is to develop a scientific and engineering basis of the steady state operation of advanced tokamak.The engineering design of the device has been optimized. The R&D program is going on. Short samples of the conductor and a CS model coil were tested. All the TF and PF coils will be manufactured and tested in Institute of Plasma Physics. Therefore, a 600-meter long jacketing line for cable-in-conduit conductors along with two winding machines, a set of VPI equipment and a test facility for the TF and PF coils are ready in ASIPP now. In this paper, the recent progress of the HT-7U is described.     

Design of the Cryostat for HT—7U superconducting Tokamak

The cryostat of HT-7U tokamak is a large vacuum vessel surrounding the entire basic machine with a cylindrical shell,a dished top and a flat bottom.The main function of HT-7U cryostat is to provide a thermal barrier between an ambient temperature test hall and a liquid helium-cooled superconducting magnet.The loads applied to the cryostat are from sources of vacuum pressure,dead weight,seismic events and electromagnetic forces originated by eddy currents.It also provides feed-through penetrations for all the conecting elements inside and outside the cryostat.The main material selected for the cryostat is stainless steel 304L.The structural analyses including buckling for the cryostat vessel under the plasma operation condition have been carried out by using a finite element code.Stress analysis results show that the maximum stress intensity was below the allowable value.In this paper,the structural analyses and design of HT-7U cryostat are emphasized.     

Linear Buckling Analysis of the HT-7U Vacuum Vessel

1. IntroductionHT-7U superconducting Tokamak, as a nationalproject, is an advanced steady-state plasma exper-imental device to be built in 2Oo3. Now all kindsof engineering design have been begun. The vac-uum vessel is one of the key parts for HT-7U de- vice, which can provide not only a clean and ultra-high vacuum env1ronment in the operatlon of plasmafor the production quilibrium and heating of thelasma, but also reliable supporting structure andvarious channels for a series of equipme…