小型移动式中子发生器

把从国外引进的高压终端与自行研制的脉冲系统等结合在一起,建成了一台小型移动式中子发生器。该中子发生器的长度是2 500 mm,重量小于1 t,可以方便地移动到所需要的实验场合。它主要由高频离子源、加速管、高压发生器、聚焦装置、供气系统、微秒脉冲系统、控制系统、真空系统和实验靶室组成。它能产生150μA的直流氘离子束和宽度为10～100μs,频率分别为10 Hz,1 000 Hz,10 000 Hz的脉冲氘离子束。D-T中子产额可达1.5×10~(10)s~(-1)。文章主要介绍了小型移动式中子发生器主要部件的工作原理和结构。     

紧凑型自聚束微波电子枪实验装置控制系统的研制

紧凑型自聚束微波电子枪的实验装置需要相应的控制体系。为此,研制了一套独立于原有大装置(200MeV LINAC)的监测控制系统。该系统基于一般控制系统的三层构架原理,由核心控制电路、光信号发射与接收电路和开关量读写电路组成,实现了时序控制、设备状态监控、联锁控制等功能,并利用上位机与现场处理器通信,达到远程操作的目的。经测试,该系统的性能参数满足并优于实际需求,试运行期间工作稳定可靠,满足实验平台的控制需求。该系统也能直接用于其他小型加速器的控制操作。     

核电高效紧凑新型蒸汽发生器设计研究

为了适应三代核电机组进一步提质增效的发展需求,在确保安全性的基础上,采用更加先进的技术、同时兼顾设计及制造技术的成熟性,研究设计了一款经济性更好、技术性能更先进的高效紧凑新型蒸汽发生器(ZH-J60型SG)。ZH-J60型SG设置了轴流式预热器和泥渣收集器,并改进设计了小型双级叶片汽水分离器。计算和分析表明,ZH-J60型SG提高了SG自然循环倍率,提升了整机功率重量比、出口蒸汽品质和运行可靠性,完全满足并在部分关键参数上超过第三代压水堆核电厂SG的水平。     

Frequency control and pre-tuning of a large aperture 500 MHz 5-cell superconducting RF cavity

The 500 MHz 5-cell superconducting RF(SRF) cavity was designed aiming to be a candidate cavity for high current accelerators. A copper prototype cavity and a niobium cavity were fabricated at SINAP in 2012. In order to ensure these cavities get the desired frequency and a good field flatness higher than 98%, frequency control was implemented in the manufacturing process and pre-tuning has been done using a simple pre-tuning frame based on the bead-pull pre-tuning method. Then, TM010-π mode frequency within 5 kHz from the target frequency was achieved and the field flatness reached 98.9% on the copper prototype cavity. Finally, the same procedure was applied to the niobium cavity to obtain a field flatness better than 98% which benefited the cavity performance in the vertical testing.     

Design and Performance of a Compact Marx Generator for Two-Electrode Gas Switch Used in ICF Power Conditioning System

As the high-current, high-coulomb transfer two-electrode graphite gas switch had no trigger electrode and must be triggered by a nanosecond pulse, a compact Marx generator was developed to produce a nanosecond rise-time, voltage level around 100 kV negative pulse to trigger the gas switch. This paper presented the structure of the compact Marx generator and the performance used in ICF power conditioning system. The effect of the ultraviolet radiation was utilized to decrease the amplitude of the breakdown voltage of the spark gaps. Coaxial structure of the metal shell was employed to reduce the inductance of the Marx generator. Additional isolation circuits were improved to prevent the electromagnetic disturbance which was significant for the application of the two-electrode graphite gas switch. The results showed that the designed compact Marx generator was suitable and have been successfully used as the trigger generator in ICF power conditioning system.     

Compact Stellarators

Stellarators offer advantages for reactors, namely the potential for steady state operation with low recirculating power (high engineering Q) and without disruptions. A substantial portion of the world fusion program is devoted to the development of stellarators as a magnetic confinement system. The world stellarator program, as it currently exists, is focused on high-aspect-ratio (R/a = 5 ? 11) designs that lead to very large reactors. For example the German advanced stellarator reactor design HSR has an aspect ratio of 12 and a major radius of 22 m. An important issue for stellarator research is whether more compact reactor designs are possible. Could the advantage of stellarators also be realized at dimensions and performance levels closer to those of the advanced tokamak reactor ARIES-RS (R = 5.5 m, neutron wall load of 4 MW/m2)? Theory has identified a class of “compact stellarator” plasma configurations that could be the basis for such a design. They are promising, but need to be studied experimentally in order to realistically assess their potential. The most cost-effective way to accomplish this is to carry out the compact stellarator proof-of-principle program that has been proposed by the U.S. stellarator community. This program would answer the basic physics questions for compact stellarators and make important contributions to the world stellarator knowledge base at a cost (about $30M/year) that is modest compared to expenditures for stellarator and tokamak research world-wide.     

同步加速器高频系统前端控制器改进设计

介绍了在CSR同步加速器高频控制系统改进项目中,高频前端控制器的改进设计。根据系统改进的具体要求,采用DSP+FPGA双电路板的体系结构,对高频前端控制器各个部分做了详细的设计,并给出了具体的资源消耗结果和设计图。     

Advanced topics on RF amplitude and phase detection for low-level RF systems

Low-level radio frequency(LLRF) systems stabilize the electromagnetic field in the RF cavities used for beam acceleration in particle accelerators. Reliable, accurate, and precise detection of RF amplitude and phase is particularly important to achieve high field stability for pulsed accelerators of free-electron lasers(FEL). The digital LLRF systems employ analog-to-digital converters to sample the frequency down-converted RF signal and use digital demodulation algorithms to calculate the RF amplitude and phase. Different sampling strategies and demodulation algorithms have been developed for these purposes and are introduced in this paper. This article focuses on advanced topics concerning RF detection,including accurate RF transient measurement, wideband RF detection, and RF detection with an asynchronous trigger, local oscillator, or clock. The analysis is based on the Swiss FEL measurements, but the algorithms introduced are general for RF signal detection in particle accelerators.     

弱电流发生装置

高内阻弱电流源的性能,在高阻测量、弱电流测试装置刻度等领域具有非常重要的作用。一般,通过高阻端接电压或晶体管方法形成的电流源精度不高。基于电容放电原理的弱电流源,利用线性变化电压对高精度电容充电;但是,其会受到充电时间的限制,连续工作能力比较差。此外,还可以利用内置放射源的电离室作为弱电流源,不但满足高内阻的要求,还可以具备长时间连续工作的能力。     

紧凑型强流ECR源

建立了１台紧凑型强流ＥＣＲ源。共振磁场由１个小电磁线圈及软铁回路产生,磁场可调,能保证放电处于最佳条件。研究了气压,微波功率及共振场对放电的影响。在５５０Ｗ的放电功率下,从直径４ｍｍ引出孔引出了３５ｍＡ的Ｈ＾＋离子束,引出Ｈ＾＋离子的质子比超过９０％,从源中还引出了７ｍＡＯ＾＋、８ｍＡＮ＾＋、１２ｍＡ Ａｒ＾＋的束流。     

Design optimization and cold RF test of a 2.6-cell cryogenic RF gun

To further improve the performance of acceler-ators, the first cryogenic normal-conducting RF gun in China was designed and manufactured. As a new and attractiv...     

RF plugging of mirror plasma

Discovery of superconducting materials that operate at high temperatures revive interest in the use of rf field for plasma confinement [1]. This paper discusses feasibility of a scheme where resonant rf cavities are attached to the mirror ends of an open system for plasma confinement.     

高温气冷堆蒸发器工程验证实验回路蒸发器传热管流量调节特性研究

高温气冷堆蒸发器工程验证实验回路蒸发器传热管流量调节精度要求很高,电动阀门能否满足调节精度要求需分析和验证。在常温、常压测试回路上测量了电动阀门在不同开度下的阻力系数(性能曲线)和阀门的调节灵敏度,然后根据测量结果分析在实际运行工况下采用单阀门和双阀门的流量调节灵敏度。结果表明,单阀调节精度较低,最小步长对应的流量变化值约为2.4%。双阀可提高调节精度,固定阀门与可调阀门的节流比为5:1时,最小步长对应的流量变化值约为0.175%,且调节精度随节流比增加而提高。     

随机脉冲发生器

本文介绍一台随机脉冲发生器,其输出脉冲序列沿时间轴按泊松规律分布。发生器的死时间为110ns,平均速率从10到10~6次/秒连续可调,平均速率控制精度达0.2％。     

High Power Cockcroft-Walton Generator

To utilize the full current capability of the regular or symmetrical cascade generator, the conventional selenium rectifiers have to be replaced by a series-connection of silicon diodes which are rather sensitive to overvoltages and overcurrents. The problem of the application and protection of silicon diodes in high voltage generators had to be overcome in connection with the design of an air-insulated 770-kV dc power supply with a rated current of 180 mA dc for the ATOMIC ENERGY OF CANADA, LTD., Chalk River, Ontario and also for a 2 MV, 30 mA test facility.