步进电机微步驱动控制的研究

本文论述了步进电机微步驱动控制的工作原理及系统组成，该驱动器能较好地改善步进电机的运行性能，具有实用性强，结构简单，成本低的优点。     

γ射线参考辐射场控制装置的研制

介绍了γ射线参考辐射场建立中控制装置硬件组成和软件设计。硬件由微机、步进电机探测卡、步进电机驱动器和步进电机等器件组成。软件采用Tubro C语言编写。     

基于DSP的运动控制器的研究与实现

步进电机定位控制是上海光源(SSRF)光束线站控制系统的主要任务,论文基于SEED_EDC138开发板设计了基于DSP的步进电机运动控制器,实现了基本的定位控制,并针对光束线站控制需求,设计了梯形速度曲线、坐标系统和操作员界面,测试结果表明,该控制器可以实现步进电机的精确定位。     

基于PC机的步进电机控制系统

研制成功了ＳＭＣ－１步进电机控制接口板并由此组成了步进电机控制系统，已将此系统应用于ＢＳＲＦ荧光实验站，导弹仿真系统等领域，效果良好。     

230 MeV超导回旋加速器Trim-rod驱动系统测试实验方案

正在230 MeV超导回旋加速器的中心区,为了最小化参考粒子的径向振荡,需要使用磁场调节棒(Trim-rod)产生一定幅值和相位一次谐波,修正参考粒子的径向位置。磁场调节棒通过步进电机驱动上下移动,因此实现对步进电机良好的控制显得十分必要。步进电机驱动器和控制器到步进电机的距离约为50m,因此驱动脉冲及传感器的反馈信号直接影响步进电机的控制性能。因此设计了一套Trim-rod驱动系统测试50m电缆长时的反馈信号衰减情况,测试实验方案如图1所示。本方案采用具有编程和调试功能的智能型步     

数字化LLRF频调环路的步进电机控制算法设计

本文介绍用于超导高频腔频率调谐环路控制中具有自动联锁保护功能的二相步进电机的控制算法。设计以可编程门阵列(FPGA)为核心部件,采用低频启动,逐步升频过渡到稳定工作状态,实现步进电机的平稳运行;通过设置联锁控制信号回路,实现步进电机在运动过程中的超限自动联锁保护功能。测试结果显示,通过优化设置不同的启动频率,不同的升频速度,实现了步进电机在上海光源超导高频腔上的稳定运行。     

步进电机控制系统的设计及其应用

介绍了基于MSP430F149单片机的步进电机控制系统的设计。在硬件部分,描述了该系统的硬件配置和工作原理;在软件部分,分析了单片机控制程序和步进电机运动的设计过程。该系统具有研制成本低且扩展好的特点,并具有软件功能强、操作使用简便等优点,满足了兰州重离子加速器冷却储存环(HIRFL-CSR)系统中对五相步进电机的各种控制要求。     

基于PLC的步进电机控制系统

本文介绍一种利用ＰＬＣ设计的步进电机的先进控制系统，该系统结构简单，可靠性高，具有较高的实用价值。     

用于探伤加速器的相位自动调整机构的研制

为实现探伤加速器微波系统微波正向包络、反向包络的相位相同，使用匹配长线及移相器来实现，在以往的实验中的相位调整是停机，调试人员进入屏蔽厅调整，这样有重复开机时的状态不一致、不重复的问题，还增加了调试的高压小时、耽误调试时间。通过采用步进电机驱动移相器的调整及编码器定位记录移相器的位置，使用PLC控制步进电机的运行，通过通讯将移相器的位置信息、剂量率传入计算机，     

步进电机光电定位自动控制系统在核物理研究中的应用

介绍了一种由微机控制的，用于核物理实验中的步进电机光电定位自动控制系统，并对硬件和软件的设计以及工作原理作了较详细的阐述。     

Development of uranium-graphite channel reactors in the USSR

Conclusions Twenty years experience in the development and operation of uranium-graphite channel reactors has confirmed their high reliability, safety, flexibility of cycle, possibility of constant improvement of construction, and the thermal circuit. At the present stage the use of high-power channel reactors successfully solves the most important national economic problem of the intensive accumulation of nuclear power capacity. Channel reactors correspond to contemporary and contemplated trends in power development.Channel reactors give the most complete answer to the modern trend to increase unit power, since there are no technical or transportation limitations on increasing their power.The transition from the construction of the RBMK-1000 to the building of the RBMK-1500 appreciably decreases the specific cost of a NPP. It is particularly important also that this transition requires hardly any increase in the operating staff of the NPP or the builders and manufacturers of equipment. This means that in the transition the productivity of nuclear power production workers is sharply increased.The present article is based on papers by V. G. Aden, Yu. M. Bulkin, A. P. Veselkin, V. K. Vikulov, V. P. Volkov, O. M. Glazkov, V. V. Goncharov, I. I. Grozdov, M. B. Egiazarov, I. Ya. Emel'yanov, A. D. Zhirnov, L. R. Kevorkov, A. Ya. Kramerov, S. P. Kuznetsov, E. P. Kunegin, L. I. Luninaya, Yu. M. Mityaev, V. I. Mikhan, K. K. Polushkin, V. V. Postnikov, V. S. Romanenko, A. P. Sirotkin, V. M. Fedulenko, S. M. Feinberg, V. N. Filippov, and R. T. Shapovalov. The authors are sincerely grateful to these colleagues.Translated from Atomnaya Énergiya, Vol. 43, No. 5, pp. 337–343, November, 1977.     

Criticality in the fabrication of ion extraction system for SST-1 neutral beam injector

For the heating of plasma in steady-state superconducting tokamak (SST-1) (Y.C. Saxena, SST-1 Team, Present status of the SST-1 project, Nucl. Fusion 40 (2000) 1069–1082; D. Bora, SST-1 Team, Test results on systems developed for the SST-1 tokamak, Nucl. Fusion 43 (2003) 1748–1758), a neutral beam injector is provided to raise the ion temperature to 1 keV. This injector has a capability of injecting hydrogen beam with the power of 0.5 MW at 30 keV. For the upgrade of SST-1, power of 1.7 MW at 55 KeV is required. Further, beam power is to be provided for a pulse length of 1000S. We have designed a neutral beam injector (S.K. Mattoo, A.K. Chakraborty, U.K. Baruah, P.K. Jayakumar, M. Bandyopadhyay, N. Bisai, Ch. Chakrapani, M.R. Jana, R. Onali, V. Prahlad, P.J. Patel, G.B. Patel, B. Prajapati, N.V.M. Rao, S. Rambabu, C. Rotti, S.K. Sharma, S. Shah, V. Sharma, M.J. Singh, Engineering design of the steady-state neutral beam injector for SST-1, Fusion Eng. Des. 56 (2001) 685–691; A.K. Chakraborty, N. Bisai, M.R. Jana, P.K. Jayakumar, U.K. Baruah, P.J. Patel, K. Rajasekar, S.K. Mattoo, Neutral beam injector for steady-state superconducting tokamak, Fusion Technol. (1996) 657–660; P.K. Jayakumar, M.R. Jana, N. Bisai, M. Bajpai, N.P. Singh, U.K. Baruah, A.K. Chakraborty, M. Bandyopadhyay, C. Chrakrapani, D. Patel, G.B. Patel, P. Patel, V. Prahlad, N.V.M. Rao, C. Rotti, V. Sreedhar, S.K. Mattoo, Engineering issues of a 1000S neutral beam ion source, Fusion Technol. 1 (1998) 419–422) satisfying the requirements for both SST-1 and its upgrade. Since intense power is to be transported to SST-1 situated at a distance of several meters from the ion source, the optical quality of the beam becomes a primary concern. This in turn, is determined by the uniformity of the ion source plasma and the extractor geometry. To obtain the desired optical quality of the beam, stringent tolerances are to be met during the fabrication of ion extractor system.

SST-1 neutral beam injector is based on positive ion source. The extraction system consists of three grids, each having extraction area of (width) 230 mm × (height) 480 mm and 774-shaped apertures of 8-mm diameter. To obtain horizontal focal length of 5.4 m and vertical of 7 m, each grid consists of two halves with 387 apertures. Two halves are inclined at an angle of 1.07 ± 0.01°. For long pulse operation, active water cooling is provided by in-laid down of dense network of 22 wavy semicircular (r = 1.1 ± 0.05 mm) cooling channels in the space available between the apertures. The required flatness of the copper plate is 100 μm and positioning tolerance of aperture is ±60 μm. The measurement obtained after fabrication is compared with the specifications. It is pointed out that fabrication within set tolerance limit could be achieved only through process of fabrication and high-resolution measurements.     

ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data

The ENDF/B-VII.1 library is our latest recommended evaluated nuclear data file for use in nuclear science and technology applications, and incorporates advances made in the five years since the release of ENDF/B-VII.0. These advances focus on neutron cross sections, covariances, fission product yields and decay data, and represent work by the US Cross Section Evaluation Working Group (CSEWG) in nuclear data evaluation that utilizes developments in nuclear theory, modeling, simulation, and experiment.The principal advances in the new library are: (1) An increase in the breadth of neutron reaction cross section coverage, extending from 393 nuclides to 423 nuclides; (2) Covariance uncertainty data for 190 of the most important nuclides, as documented in companion papers in this edition; (3) R-matrix analyses of neutron reactions on light nuclei, including isotopes of He, Li, and Be; (4) Resonance parameter analyses at lower energies and statistical high energy reactions for isotopes of Cl, K, Ti, V, Mn, Cr, Ni, Zr and W; (5) Modifications to thermal neutron reactions on fission products (isotopes of Mo, Tc, Rh, Ag, Cs, Nd, Sm, Eu) and neutron absorber materials (Cd, Gd); (6) Improved minor actinide evaluations for isotopes of U, Np, Pu, and Am (we are not making changes to the major actinides ^235,238U and ²³⁹Pu at this point, except for delayed neutron data and covariances, and instead we intend to update them after a further period of research in experiment and theory), and our adoption of JENDL-4.0 evaluations for isotopes of Cm, Bk, Cf, Es, Fm, and some other minor actinides; (7) Fission energy release evaluations; (8) Fission product yield advances for fission-spectrum neutrons and 14 MeV neutrons incident on ²³⁹Pu; and (9) A new decay data sublibrary.Integral validation testing of the ENDF/B-VII.1 library is provided for a variety of quantities: For nuclear criticality, the VII.1 library maintains the generally-good performance seen for VII.0 for a wide range of MCNP simulations of criticality benchmarks, with improved performance coming from new structural material evaluations, especially for Ti, Mn, Cr, Zr and W. For Be we see some improvements although the fast assembly data appear to be mutually inconsistent. Actinide cross section updates are also assessed through comparisons of fission and capture reaction rate measurements in critical assemblies and fast reactors, and improvements are evident. Maxwellian-averaged capture cross sections at 30 keV are also provided for astrophysics applications.We describe the cross section evaluations that have been updated for ENDF/B-VII.1 and the measured data and calculations that motivated the changes, and therefore this paper augments the ENDF/B-VII.0 publication [M. B. Chadwick, P. Oblo?inský, M. Herman, N. M. Greene, R. D. McKnight, D. L. Smith, P. G. Young, R. E. MacFarlane, G. M. Hale, S. C. Frankle, A. C. Kahler, T. Kawano, R. C. Little, D. G. Madland, P. Moller, R. D. Mosteller, P. R. Page, P. Talou, H. Trellue, M. C. White, W. B. Wilson, R. Arcilla, C. L. Dunford, S. F. Mughabghab, B. Pritychenko, D. Rochman, A. A. Sonzogni, C. R. Lubitz, T. H. Trumbull, J. P. Weinman, D. A. Br, D. E. Cullen, D. P. Heinrichs, D. P. McNabb, H. Derrien, M. E. Dunn, N. M. Larson, L. C. Leal, A. D. Carlson, R. C. Block, J. B. Briggs, E. T. Cheng, H. C. Huria, M. L. Zerkle, K. S. Kozier, A. Courcelle, V. Pronyaev, and S. C. van der Marck, “ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology,” Nuclear Data Sheets 107, 2931 (2006)].     

The use of monodirectional neutron sources for the investigation of shielding (B-2 apparatus in a BR-5 reactor)

The report describes the B-2 apparatus, installed in a BR-5 fast reactor, for investigating the passage of neutrons through various shielding materials. It is shown that the monodirectional neutron disc source used in this apparatus makes it possible to obtain detailed information on the spatial-energy and angular distributions of the neutrons in the shielding. The effect of the angular distribution of the radiation leaving the source on the attenuation factor of this radiation in shielding was also investigated.In conclusion I would like to express my sincere thanks to A. I. Leipunskii for valuable advice during the formulation of the scheme of investigations concerning the passage of neutrons in different media from monodirectional sources, and I. I. Bondarenko, V. V. Orlov, V. I. Kukhtevich, Yu. A. Kazanskii, B. I. Sinitsyn, E. S. Matusevich, B. P. Shemetenko, Sh. S. Nikolaishvili, V. P. Mashkovich, and A. A. Abagyan for discussing the results of this work; and, finally, D. S. Pinkhasik 'and N. N. Aristarkhov for considerable help in making the B-2 apparatus.     

Accurate universal parameterization of absorption cross sections III--light systems.

Our prior nuclear absorption cross sections model [R.K. Tripathi, F.A. Cucinotta, J.W. Wilson, Nucl. Instr. and Meth. B 117 (1996) 347; R.K. Tripathi, J.W. Wilson, F.A. Cucinotta, Nucl. Instr. and Meth. B 129 (1997) 11] is extended for light systems (A < or = 4) where either both projectile and target are light particles or one is light particle and the other is medium or heavy nucleus. The agreement with experiment is excellent for these cases as well. Present work in combination with our original model provides a comprehensive picture of absorption cross sections for light, medium and heavy systems. As a result the extended model can reliably be used in all studies where there is a need for absorption cross sections.     

Electron Cyclotron Resonance Multiply Charged Ion Sources

We describe three ion sources working in our laboratory that deliver multiply charged ion beams. All of them are E.C.R. ion sources and are characterized by the fact that the electrons are emitted by the plasma itself and are accelerated to the adequate energy through electron cyclotron resonance (E.C.R.). They can work without interruption during several months in a quasi-continuous regime. (Duty cycle: <.5). Their charge state distributions (C.S.D.) depend on the size and the characteristics of the plasma. For the smallest source the performances are comparable to those of P.I.G. sources. For the biggest source, the C.S.D. tend towards those obtained by EBIS-type sources. Experimental results and guiding ideas concerning these three ion sources are reviewed.     

Preparation and Preliminary Biodistribution of No-Carrier-Added Meta［*I］ iodobenzylguanidine

No-carrier-added meta-［*I］iodobenzylguanidine((n.c.a.)［^123/131I］MIBG) has been considered to be promising diagnostic agents for oncology and cardiology, or as targeted radiotherapeutics for neuroendocrine tumors. The synthesis of a fluorous supported precursor for the purification without HPLC of n.c.a.［*I］MIBG was presented and its structure was determined. The precursor was labeled with radioactive iodine and the preliminary biodistribution of n.c.a.［*I］MIBG was studied. The uptake of n.c.a.［¹²⁵I］MIBG were significantly higher than that of c.a.［¹²⁵I］MIBG in heart, spleen, lung and adrenals. This facile preparation method of n.c.a.［*I］MIBG would allow its wider application in clinic.     

The use of empirical constants in shielding design

The article contains a generalization of the results of experimental and theoretical investigations relating to the determination and use of removal cross sections. It also considers the questions of the possibility of extending the region of applicability of empirical constants for the design of various kinds of neutrons shielding. A table gives the values of empirical constants for calculating the penetration of fast neutrons.The authors are also grateful to I. I. Bondarenko, V. I. Kukhtevich, Yu. A. Kazanskii, A. A. Abagyan, D. V. Pankratov, and A. P. Suvorov for their valuable advice in preparing the material for publication.     

Existence of a predominant direction of light emission from oxide crystalline scintillators

Institute of Single Crystals, Ukrainian National Academy of Sciences. Yu. G. Zdesenko and A. S. Nikolaiko. Institute of Nuclear Research, Ukrainian National Academy of Sciences. Translated from Atomnaya énergiya, Vol. 79, No. 6, pp. 464–466, December, 1995.     

The shielding effect of U238 resonances on the resonance absorption of U235

This paper discusses the question of the mutual effect of resonance neutron absorption by U²³⁸ and U²³⁵ inside a slug, where the resonance absorption is due mainly to volume absorption. As shown by the theoretical calculations and experiments given in the paper, the resonance absorption of neutrons by U²³⁵ in the epithermal region of energies for natural metallic and 10% uranium depends on the effect of the U²³⁸ resonance levels.Calculations may be made in a similar way for other elements.In conclusion the authors epress their gratitude to V. V. Orlov, G. Ya. Rumyantsev, and B. G. Dubovskii for their discussion of the present work. The authors also thank Pen-fan, A. P. Dolgolenko, A. P. Korneev, M.M. Kuzichkin, K. N. Mokhnatkin, and Yu. I. Starykh, who participated in the experiments and calculations.