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1.
A critical issue in the design of the ITER low field side reflectometer is the transmission line (TL) system. A TL connects each launcher to a diagnostic instrument. Each TL will typically consist of ~42?m of corrugated waveguide and up to ten miter bends. Important issues for the performance of the TL system are mode conversion and reflections. Minimizing these issues are critical to minimizing standing waves and phase errors. The performance of TL system is analyzed and recommendations are given.  相似文献   

2.
The ITER low field side reflectometer faces some unique design challenges, among which are included the effect of relativistic electron temperatures and refraction of probing waves. This paper utilizes GENRAY, a 3D ray tracing code, to investigate these effects. Using a simulated ITER operating scenario, characteristics of the reflected millimeter waves after return to the launch plane are quantified as a function of a range of design parameters, including antenna height, antenna diameter, and antenna radial position. Results for edge/SOL measurement with both O- and X-mode polarizations using proposed antennas are reported.  相似文献   

3.
Any plasma diagnostic in ITER must be able to operate at temperatures in excess of 200?°C and neutron loads corresponding to 0.1 dpa over its lifetime. To achieve this aim for the bolometer diagnostic, a miniaturized metal resistor bolometer detector based on Pt absorbers galvanically deposited on SiN membranes is being developed. The first two generations of detectors featured up to 4.5?μm thick absorbers. Results from laboratory tests are presented characterizing the dependence of their calibration constants under thermal loads up to 450?°C. Several detectors have been tested in ASDEX Upgrade providing reliable data but also pointing out the need for further optimization. A laser trimming procedure has been implemented to reduce the mismatch in meander resistances below 1% for one detector and the thermal drifts from this mismatch.  相似文献   

4.
高压板翅式散热器由于其承受的高压特性导致产品稳定性较差,承压强度难以满足要求。为了提高钎焊封条与钎接用铝合金板的钎焊强度,本文利用MSC模拟分析软件对不同类型封条结构进行强度模拟分析,比较不同结构的优越性,并通过试验验证得到最理想的结构类型,为封条的结构优化提供设计参考。  相似文献   

5.
为了研究激光辐照过程中材料的耦合特性及耦合特性随温度的变化规律,设计了一套主体为半椭球壳体,可用于激光辐照过程中材料反射率在线测量的共轭反射计实验装置,研制完成的初样其主体内壁在可见-长波红外光谱范围内镜面反射率优于70%。介绍了测量原理和测试系统的设计方案,采用光线追迹模拟方法研究了主体部分的设计参数,分析了开孔位置、入射方向、光斑尺寸、收集孔径以及内壁反射特性对测量收集效率的影响。结果表明:在设计指标下选用探测光束直径为Φ10 mm、收集孔径为Φ38.1 mm时,收集效率可达到完全收集的97.8%,满足测量要求。另外,用短波激光测量内表面光洁度有更高要求;理想面型条件下,限定范围内的收集效率主要由内壁镜面反射率决定;因此,半椭球内壁的面型、光洁度、反射率及其均匀性是影响测量精度的主要因素。  相似文献   

6.
基于混沌信号的光时域反射仪   总被引:2,自引:0,他引:2  
研制了基于混沌信号相关测距技术的光时域反射仪样机。介绍了该仪器的混沌光源设计,硬件系统结构设计和软件算法流程设计。以G.652.B单模光纤为被测对象,对该仪器检测光纤故障的技术指标进行了分析测试。测试结果表明,在102km内可实现与距离无关的50cm空间分辨率,比现有飞行时间测量技术提高了约两个数量级,可实现对光纤不同类型反射事件的识别,完全满足无源光网络中的故障检测。  相似文献   

7.
集装箱侧面吊起重机构优化设计   总被引:1,自引:0,他引:1  
冯晓梅  詹隽青 《机械设计》2004,21(12):21-25
以集装箱侧面吊理想工况工作条件下机构力学分析为基础,建立了特殊工况工作条件下起重机构优化设计数学模型,编制了优化计算程序,进行了结构优化设计,并分析了该特殊工况危险状态下吊臂的强度。通过样机应力测试结果与优化设计结果的对比分析,为结构的进一步优化提供了依据,其分析结果也可供同类产品设计参考。  相似文献   

8.
The International Thermonuclear Experimental Reactor will have wide angle viewing systems and a divertor thermography diagnostic, which shall provide infrared coverage of the divertor and large parts of the first wall surfaces with spatial and temporal resolution adequate for operational purposes and higher resolved details of the divertor and other areas for physics investigations. We propose specifications for each system such that they jointly respond to the requirements. Risk analysis driven priorities for future work concern mirror degradation, interfaces with other diagnostics, radiation damage to refractive optics, reflections, and the development of calibration and measurement methods for varying optical and thermal target properties.  相似文献   

9.
A new design of a linear time of flight mass spectrometer (ToFMS) is implemented that gives nearly field-free interaction region without compromising on the mass resolution. The design addresses problems that would arise in a conventional Wiley-McLaren type of ToFMS: (i) field leakages into the charged particle-molecule interaction region from various components of the mass spectrometer, including that through the high transparency mesh used to obtain evenly distributed electric fields; (ii) complete collection and transportation of the ions produced in the interaction region to the detector, which is essential for high sensitivity and cross section measurements. This ToFMS works over a wide range of masses from H(+) to a few hundred Daltons and would be the most suitable for low energy charged particle-molecule interaction studies. Performance of the ToFMS has been tested by measuring the partial ionization cross sections for electron impact on CF(4).  相似文献   

10.
Calibration of optical time domain reflectometers by military and industrial users can be achieved by a number of published test procedures. For some performance parameters, a particularly convenient method for establishing measurement verification and traceability to national standards is through the use of a standard reference fiber. NIST has begun a program to evaluate such test lightguides. Prototype standard reference fibers have been characterized for spectral attenuation, group delay, group index, and length. This paper describes measurement methods and tolerances for these devices.  相似文献   

11.
An ionization chamber with an operating supply voltage of 10 V has been designed for use at the ITER. The sensitivity of the chamber filled with air at atmospheric pressure is 100–200 times higher than the sensitivity of the chamber pumped down to a pressure of 10−3–10−4 Torr. It is shown that application of the supply voltage modulation technique allows the pickup noise to be substantially reduced; as a result, the amplifier can be located at a large (70–100 m) distance from the chamber. Results of the experiments aimed at testing this technique on the T-10 facility are described. Original Russian Text ? Yu.V. Gott, M.M. Stepanenko, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 2, pp. 117–121.  相似文献   

12.
A general virtual experiment for the time-of-flight neutron reflectometer is introduced to simulate the experimental data collection and processing, including instrument simulation, sample modeling, detector simulation, and data reduction. The process mimics the experimental data processing and reduction routines. The reduced data agree well with the theoretical calculation, confirming the reliability of the data reduction algorithms. The methodology and algorithms developed in this study pave the way for the future development of data processing and data reduction software for the time-of-flight neutron reflectometer of China Spallation Neutron Source.  相似文献   

13.
The neutron fields in the collimators of a new design for the vertical neutron camera (VNC) of the ITER have been calculated for a standard isotropic bulk DT neutron source. The neutron and gamma-ray spectra and flux densities at the neutron detector sites have been calculated. The signal-to-background ratio of VNC detectors (238U-based fission chambers and diamond detectors) has been estimated. The signal-to-background ratios versus the threshold energy were calculated for the diamond detectors operating in the threshold counter mode. The effect of background Γ-ray radiation on the performance of the diamond detectors in the VNC environment has been estimated. The radiation heating of the VNC structural components has been calculated. The serviceability of the VNC with the proposed design has been demonstrated.  相似文献   

14.
The ITER heating neutral beam (HNB) injector, based on negative ions accelerated at 1 MV, will be tested and optimized in the SPIDER source and MITICA full injector prototypes, using a set of diagnostics not available on the ITER HNB. The RF source, where the H(-)∕D(-) production is enhanced by cesium evaporation, will be monitored with thermocouples, electrostatic probes, optical emission spectroscopy, cavity ring down, and laser absorption spectroscopy. The beam is analyzed by cooling water calorimetry, a short pulse instrumented calorimeter, beam emission spectroscopy, visible tomography, and neutron imaging. Design of the diagnostic systems is presented.  相似文献   

15.
A quadruple-bend achromatic (QBA) cell, defined as a supercell made of two double-bend cells with different outer and inner dipole bend angles, is found to provide a factor of 2 in lowering the beam emittance relative to the more conventional double-bend achromat. The ratio of bending angles of the inner dipoles to that of the outer dipoles is numerically found to be about 1.5-1.6 for an optimal low beam emittance in the isomagnetic condition. The QBA lattice provides an advantage over the double-bend achromat or the double-bend nonachromat in performance by providing a small natural beam emittance and some zero-dispersion straight sections. A lattice with 12 QBA cells and a preliminary dynamic aperture study serves as an example.  相似文献   

16.
在常规低场核磁共振(NMR)实验中,NMR响应的空间均匀度与螺线管收发线圈的尺寸、样品的大小以及采用的脉冲序列类型有关,根据这些条件可以确定具有给定射频(RF)场均匀度的线圈最小尺寸.考虑到螺线管匝数、线径等因素对信噪比的影响,对线圈的各项参数进行了优化,设计了具有最佳信噪比性能的螺线管线圈.  相似文献   

17.
Microdiffraction patterns, obtained when an electron beam of small diameter (of the order of 1 nm) runs parallel to the flat face of a small crystal, show effects dependent on the extension of the electrostatic potential field of the crystal into the vacuum. Patterns from small MgO smoke crystals obtained with a modified scanning transmission electron microscope show strong streaks extending from the zero, or other, diffraction spots and the appearance of spots in the positions of forbidden reflections. The main features of the patterns can be explained by use of a simple, geometric optics model and the assumption of a mathematically simple form for the potential field allows reasonable agreement between the predicted and observed dependence on experimental parameters such as the crystal thickness in the beam direction.  相似文献   

18.
A diagnostic array has been developed for studying the operating modes of the divertor in the ITER tokamak-reactor using the Thomson scattering technique. The aim of this study is to measure the spatial profiles of the electron temperature and density. The structure of the diagnostic setup was selected on the basis of a classical diagnostic geometry and the high-resolution LIDAR system, which provide access to different regions of the divertor plasma. A severe radiation environment, limited access to the plasma in the ITER divertor, and a high-dust environment (the divertor plate erosion material) in the divertor volume pose many problems for performing diagnostics under unique conditions having no analogs in the tokamaks that are now in operation. Different methods for protecting optical surfaces from plasma-enriched deposition are proposed and analyzed. The efficiency of these methods has been demonstrated in bench tests. The concept of laser and detector systems and diffraction polychromators capable of operating at different electron temperatures with a lower limit of 1 eV, has been justified and approved.  相似文献   

19.
针对超导极向场(Poloidal field, PF)超导导体外方内圆的结构特点,以ABAQUS软件分析为手段,采用四辊轮缩径成形工艺对导体缩径成形进行研究。对缩径成形原理、变形区金属的流动规律和横截面受力情况进行理论分析,设计四道次成形工序,并通过拉伸试验获得导体材料316L不锈钢的应力应变曲线。数值模拟结果表明导体缩径过程中应力应变分布不均匀,最大应力出现在接触位置后端,应变集中在四个圆角部位,符合金属流动最小阻力定律。在分析软件中测量变形后导体的截面尺寸,在规定的使用范围之内。在自主设计的成形机上进行试验,取5个不同截面测量尺寸并取平均值,所得结果与模拟结果相近,符合导体尺寸要求,验证了该成形方案的可行性。  相似文献   

20.
根据ITER馈线系统特点,采用模板剖建零件库,利用分层装配技术进行装配,提高了设计效率。通过有限元分析,及早发现设计问题,提高了馈线设计的合理性。  相似文献   

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