ITER上窗口屏蔽中子学分析研究

利用CAD/MCNP自动建模程序MCAM建立ITER新上窗口中子学计算模型,使用中子/光子耦合输运程序MCNP/4CI、AEA聚变核数据库FENDL1.0和集成上窗口模型的ITER基本中子学模型计算并分析上窗口新的工程设计的屏蔽能力以检验设计的合理性。结果表明,与以前的上窗口设计相比,新设计的上窗口的周围剂量控制点的快中子注量率、停堆剂量率以及线圈核热等都增大了好几倍,建议进一步改进上窗口设计。     

ITER中国液态锂铅实验包层模块中子学分析

基于ITER装置全模型,借助于MCNP自动建模程序MCAM,将TBM模块插入该模型的赤道窗口,使用MCNP/4C和FENDL1.0数据库,对DLL和SLL两个典型子模块设计进行三维中子学计算和分析,给出TBM模块核热功率密度分布以及氚增殖能力.     

ITER屏蔽包层活化分析

作为国际热核聚变实验堆(ITER)的重要部件之一,屏蔽包层承受高强度聚变中子辐照,需要定期更换和维修。当活化的屏蔽包层从ITER托卡马克装置移到热室时,可能会给工作人员造成严重的辐射照射,是ITER大厅和热室屏蔽设计的重要辐射源。文中基于ITER最新中子学分析基准模型和"二步法"停堆剂量计算方法,使用超级蒙特卡罗核计算仿真软件系统SuperMC针对15号屏蔽包层建立精细的中子学模型,并计算分析包层的活化情况及最严重情况下的周围辐射剂量率,并初步应用于ITER赤道窗口室的屏蔽分析。计算结果显示,单个包层周围最大剂量率为350 Sv/hr,当传送小车停留在赤道窗口室内时,窗口室屏蔽门外剂量率高于10 mSv/hr,不足以满足设计要求。     

Neutronics analysis and nuclear heating measurement up to the TFC in a mock-up of the ITER inboard shield

A mock-up of ITER including the inboard shield, the vacuum vessel and the coil region, was set up at ENEA Frascati and irradiated with 14 MeV neutrons produced by the Frascati Neutron Generator (FNG). The mock-up dimensions and materials composition are consistent with the current ITER design.The primary objective of the experiment was to validate the MCNP calculations (C) of nuclear heating measured (E) in the region corresponding to the ITER Toroidal Field (TF) coil. An accuracy on C/E ratio ≤±10% was required.The neutronics and shielding properties of the mock-up were also studied throughout the measurement of selected activation reaction rates up to about 1 m depth. Due to the very low activity induced in the foils, the measurements in the deepest experimental positions were performed at the underground low background facility of the Laboratori Nazionali del Gran Sasso, using ultra-low background high purity germanium (HPGe) detectors.The measured reaction rates and nuclear heating were thus compared with the results of the Monte Carlo code MCNP5 coupled with the FENDL-2.1 library.     

Evaluation of the ATCA fast controller standard for ITER diagnostics

ITER project's long time span and the nature of the instrumentation and control (I&C) procurement procedures for the Plant Systems require that the ITER Organization defines and follows well recognized standards which are used both by the industry and in physics experiments. The ITER I&C standards are defined in the Plant Control Design Handbook (PCDH) [1]. The ITER Organization has selected PCI Express and Ethernet for IO intercommunication to be used for plant system instrumentation for fast controllers. The decision on the usage of serialized I/O bus protocols is based on the impressive performance and the commercial availability. The form factors that will be supported by CODAC include PXIe, MicroTCA, and AdvancedTCA platforms. While the PXIe form factor is already well established for instrumentation purposes through the PXI Systems Alliance (www.pxisa.org), the AdvancedTCA and MicroTCA platforms which were originally targeted for the telecommunications market (www.picmg.org) are currently optimized and specified for instrumentation use through the xTCA extensions for physics [2]. The objective of this study is the evaluation of an integrated ATCA controller design using only commercial components.     

Optimization of optical filters for ITER edge Thomson scattering diagnostics

In the ITER edge Thomson scattering measurement system, polychromators with optical band-pass filters and avalanche photodiodes are planned to be used. In this paper, we optimized the transmission wavelength ranges of the optical filters by a numerical method. Since measurements in a high electron temperature range are required for the measurement system, the Thomson spectrum could overlap a strong line emission of D_α when the electron temperature is rather high. It is shown that a filter whose transmission wavelength range is shorter than D_α becomes important to decrease the measurement error in the high temperature range. Moreover, it is found that a filter whose transmission wavelength range is above 1064 nm (laser wavelength) is useful to improve the measurement accuracy, in particular, when the number of filters is more than six.     

Manufacturing preparations for the European Vacuum Vessel Sector for ITER

The contract for the seven European Sectors of the ITER Vacuum Vessel, which has very tight tolerances and high density of welding, was placed at the end of 2010 with AMW, a consortium of three companies. The start-up of the engineering, including R&D, design and analysis activities of this large and complex contract, one of the largest placed by F4E, the European Domestic Agency for ITER, is described. The statutory and regulatory requirements of ITER Organization and the French Nuclear Safety regulations have made the design development subject to rigorous controls. AMW was able to make use of the previous extensive R&D and prototype work carried out during the past 9 years, especially in relation to advanced welding and inspection techniques. The paper describes the manufacturing methodology with the focus on controlling distortion with predictions by analysis, avoiding use of welded-on jigs, and making use of low heat input narrow-gap welding with electron beam welding as far as possible and narrow-gap TIG when not. Further R&D and more than ten significant mock-ups are described. All these preparations will help to assure the successful manufacture of this critical path item of ITER.     

FAST: A European ITER satellite experiment in the view of DEMO

Fusion Advanced Studies Torus (FAST) aims to contribute to the exploitation of ITER and to explore innovative DEMO technology. FAST has been designed to study, in an integrated scenario: (a) relevant plasma-wall interaction problems, with a large power load (P/R ～ 22 MW/m; P/R² ～ 12 MW/m²) and with a full metallic wall; (b) to tackle operational problems in regimes with relevant fusion parameters; (c) to investigate the non-linear dynamics of fast particles (alpha like) in burning plasmas. FAST will operate on a wide parameters range, namely in high performance H-mode (BT ～ 8.5 T; IP ～ 8 MA) as well as in advanced Tokamak operation up to full non-inductive current scenario (IP ～ 2 MA). The main heating is based on 30 MW ICRH, but the ports have been designed to allocate up to 20 MW of 1 MeV NNBI. Helium gas at 30 K is used for cooling of the full machine, a preliminary analysis shows the possibility of realizing FAST with a complete superconductor set of coils. An innovative active system is under development to reduce and to control the magnetic ripple. Tungsten (W) or liquid lithium (L–Li) has been chosen for the divertor material plates and the code EDGE2D has been used to optimize the divertor geometry.     

The first performance of the facility for testing ITER CC conductor short sample

A new facility had been set up to test the low temperature properties of the short sample of the small-size cable-in-conduit conductor (CICC). The facility consisted of the background magnet which could provide 7 T centric magnetic field, a 50 kA superconducting transformer which provided sample current, a 500 W/4.5 K helium refrigerator which produced both the liquid helium (LHe) and supercritical helium (SHe). An ITER CC conductor short sample was prepared and measured in this testing system. T_cs of 7.02 K (@4.1 T, 10 kA) and I_c of 8.9 kA (@4.1 T, 7.06 K) were measured.     

ITER中国液态锂铅实验包层模块活化特性分析与废料处理

使用中子学程序系统VisualBUS和活化数据库EAF-99对DFLL-TBM的高级子模块DLL-TBM的活化特性进行了计算和分析,包括DLL-TBM各部件在不同停堆时间的活度、衰变余热和剂量率.活化计算所需要的三维中子能谱通过MCNP/4C中子/光子输运程序和国际原子能机构发布的FEND1.0数据库计算得到.在活化计算分析的基础上,参照欧洲聚变堆安全和环境评估(SEAFP)策略中有关核废料的处理标准评估了TBM各区材料在退役后的废料处理工作,包括核废料应该采用何种适当的方式进行处理及其被完全清除干净的可行性.     

Project management techniques used in the European Vacuum Vessel sectors procurement for ITER

The contract for the seven European Sectors of the ITER Vacuum Vessel (VV) was placed at the end of 2010 with a consortium of three Italian companies. The task of placing and the initial take-off of this large and complex contract, one of the largest placed by F4E, the European Domestic Agency for ITER, is described. A stringent quality controlled system with a bespoke Vacuum Vessel Project Lifecycle Management system to control the information flow, based on ENOVIA SmarTeam, was developed to handle the storage and approval of Documentation including links to the F4E Vacuum Vessel system and ITER International Organization System interfaces. The VV Sector design and manufacturing schedule is based on Primavera software, which is cost loaded thus allowing F4E to carry out performance measurement with respect to its payments and commitments. This schedule is then integrated into the overall Vacuum Vessel schedule, which includes ancillary activities such as instruments, preliminary design and analysis. The VV Sector Risk Management included three separate risk analyses from F4E and the bidders, utilizing two different methodologies. These efforts will lead to an efficient and effective implementation of this contract, vital to the success of the ITER machine, since the Vacuum Vessel is the biggest single work package of Europe's contribution to ITER and is the largest component of the ITER device.     

聚变脉冲中子源特性的近距离测量方法

介绍在近距离条件下,测量聚变脉冲中子源的时间谱、能谱和产额的一种方法-两测点解谱法,对该方法的局限性作了简要地讨论。     

The JET ITER-like wall experiment: First results and lessons for ITER

The JET programme is strongly focused on preparations for ITER construction and exploitation. To this end, a major programme of machine enhancements has recently been completed, including a new ITER-like wall, in which the plasma-facing armour in the main vacuum chamber is beryllium while that in the divertor is tungsten—the same combination of plasma-facing materials foreseen for ITER. The goal of the initial experimental campaigns is to fully characterise operation with the new wall, concentrating in particular on plasma-material interactions, and to make direct comparisons of plasma performance with the previous, carbon wall. This is being done in a progressive manner, with the input power and plasma performance being increased in combination with the commissioning of a comprehensive new real-time protection system. Progress achieved during the first set of experimental campaigns with the new wall, which took place from September 2011 to July 2012, is reported.     

基于铝箔封装碳酸锂探测片产氚率测量的液闪样品制备方法

氚增殖包层中产氚率的测量是聚变核能系统中需要研究的重要问题之一,本文开展了用于产氚率测量的Al箔封装碳酸锂探测片液闪样品制备化学处理方法的研究。结果表明,首先采用氢氧化钠溶液来溶解Al箔,然后再用盐酸溶解碳酸锂探测片的溶解方式,能制成透明度高且无分层的液闪样品。为了提高测氚计数效率和保证样品兼容性,对20 m L的标准液闪样品,闪烁液体积应至少取12 m L,同时还应将液闪样品保持在10-20°C范围进行储存和测量。