A study of the performance of an induction sensor for an accelerator of charged microparticles

The design details and parameters of an induction sensor for a linear accelerator that is used to measure the velocity and charge of accelerated particles are described. A theoretical calculation of the voltage picked up from the Faraday cup of the induction sensor versus the particle parameters is presented. The essential feature of this calculation is the fact that the induction-sensor voltage is considered not only as a function of the velocity and charge of a detected charged particle, but also as a function of the coordinate of this particle. The experimental data that characterize the performance of the induction sensor are presented.     

A pulse power supply of the linear induction accelerator

A pulse power system of the induction electron accelerator intended for parameters of 2 MeV, 2 kA, and operating in the double-pulse mode is presented. The schematic diagram and main elements of the pulse system are described, and the main technical solutions intended to produce a set of pulses with 21-kV peak voltages, peak currents of up to 8 kA, and 200-ns durations across a resistive-inductive load are indicated. The experimental data, which were obtained when separate units and the whole power system operated on the rated duty, are given.     

小型非晶三相感应电机铁芯的性能

以常见的小型三相异步电机为研究对象,建立了三相异步电机模型,并用铁基非晶材料和硅钢材料分别制作了异步电机的定子铁芯,研究了非晶铁芯与硅钢铁芯的性能和特点。采用软磁交流测试系统对两种材料制成的铁芯进行了交流损耗和矫顽力的测试,测试结果显示:在相同的频率和磁感应强度下,非晶铁芯损耗仅为传统硅钢铁芯损耗的1/3左右,而其剩磁仅为传统铁芯剩磁的1/4,表明非晶铁芯的损耗和矫顽力远小于硅钢铁芯的损耗和矫顽力,且工作频率越高,二者数据差别越大,说明非晶材料较硅钢材料具有更优异的软磁性。建立了三相异步电机的有限元分析模型,对非晶合金铁芯电机和传统硅钢铁芯电机进行了有限元求解。结果显示,采用非晶定子铁芯的电机比传统采用硅钢定子铁芯的电机更加高效节能。该研究成果为深入开展铁基非晶材料在异步电机中的应用提供了参考。     

Evaluation of cellulose electro-active paper made by tape casting and zone stretching methods

Cellulose has been discovered as a smart material that can be used as sensor and actuator material. In this paper, cellulose smart material termed as electro-active paper (EAPap) is prepared by an automated process that includes tape casting and zone stretching. To evaluate characteristics of the EAPap, its Young’s modulus and piezoelectric charge constant are measured depending on the orientation angle, in comparison with the manually fabricated EAPap results. The zone stretching method can effectively align the cellulose fibers in the EAPap so as to improve its Young’s modulus as well as piezoelectric charge constant. The 0 degree oriented sample shows its maximum Young’s modulus and the 45 degree oriented sample exhibits the maximum piezoelectric charge constant. This 45 degree is associated with its shear piezoelectricity. The actuator performance of EAPap is evaluated by measuring its bending displacement depending on the orientation angle and the excitation voltage. The 45 degree oriented sample exhibits the maximum bending displacement. Details of the material preparation, the automation process, characterization and the actuator performance are addressed. This automated process that includes tape casting and zone stretching is suitable for mass production of the EAPap.     

Magnetic induction beam monitors of the NESTOR facility

A magnetic induction monitor of the beam center position, operating in the damped self-oscillating mode, and a beam current amplitude monitor, operating in the pulse mode, are described. These monitors are placed in the transport channel of the N100M electron storage ring of the NESTOR facility. The signal processing module of the monitors has been produced to the CAMAC standard using a field programmable gate array (FPGA). The signals from the sensors are measured by 12-bit 40-MHz analog-to-digital converters. The expressions for calculating beam coordinates X and Y in the form of two third-order polynomials and the sensitivity of the sensors in the center of the monitors have been determined by testing on the test bench. The sensitivity of the current sensor is 17.5 V/A, and that of the position sensors is 4.25 V/A. The construction of the monitors, designed electronics, and procedure allow one to measure the position of the beam current center in an aperture of 24 mm with an accuracy of 7% and the beam current amplitude with an accuracy of 5% for single current pulses of the linear accelerator.     

Characteristic impedance and capacitance analysis of Blumlein type pulse forming line of accelerator based on tape helix

In this paper, the electromagnetic dispersion theory and the classic telegraph equations were combined to calculate the important parameters of the helical Blumlein pulse forming line (BPFL) of accelerator based on tape helix. In the work band of the BPFL at several hundred ns range, electromagnetic dispersion characteristics were almost determined by the zeroth harmonic. In order to testify the dispersion theory of BPFL in this paper, filling dielectrics, such as de-ionized water, transformer oil, and air were employed in the helical BPFL, respectively. Parameters such as capacitance, inductance, characteristic impedance, and pulse duration of the BPFL were calculated. Effects of dispersion on these parameters were analyzed. Circuit simulation and electromagnetic simulation were carried out to prove these parameters of BPFL filled with these three kinds of dielectrics, respectively. The accelerator system was set up, and experimental results also corresponded to the theoretical calculations. The average theoretical errors of impedances and pulse durations were 3.5% and 3.4%, respectively, which proved the electromagnetic dispersion analyses in this paper.     

Control system of a linear induction accelerator of an X-ray complex: Structure,hardware, and test performance

The structure, operation logic, and hardware tools of the control system of a linear induction accelerator for an X-ray complex are considered. The hardware developed in the CompactPCI standard for the control system is described. The possibility of embedding of smart microelectronic equipment into high-voltage elements of the facility is analyzed.     

A magnesium vapor charge-exchange target for an accelerator mass spectrometer

The target design and results of experiments aimed at stripping carbon ions in magnesium vapor are presented. It is proposed to substitute such a target for gas targets conventionally used in accelerator mass spectrometers, which will reduce the background ion charge exchange outside the target. Original Russian Text ? V.F. Klyuev, V.V. Parkhomchuk, S.A. Rastigeev, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 2, pp. 101–104.     

Simulation of micrometeorites using an electrodynamical accelerator

Results of experiments with a multiparameter detector of high-speed dust particles are presented. This detector is composed of induction (a Faraday cup), ionization, and photoelectric sensors. It allows simulation of micrometeorites over wide ranges of masses and velocities by measuring secondary effects due to collisions of particles with a wall. Experiments aimed at detecting high-speed dust particles have been carried out using an electrodynamical accelerator with an effective accelerating voltage of ∼650 kV. Original Russian Text ? N.D. Semkin, K.E. Voronov, A.V. Piyakov, I.V. Piyakov, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 4, pp. 159–165.     

汽车车锁锁芯自动装配系统的研制开发

为了改变我国汽车用车锁锁芯手工装配劳动强度大、效率低的现状,研制开发成功了汽车车锁锁芯自动装配系统.介绍了组成系统各部分的主要工作原理,主要包括测号站、叶簧输送、叶簧站、叶片站、直线运动平台及夹具站等.     

辐照用加速器调制器的设计

本文介绍了用于辐照加速器的速调管脉冲调制器的部分主要部件的理论计算,依据理论计算得出了调制器部分主要部件的参数.并简要介绍了用于辐照加速器的脉冲调制器的系统概况、性能和技术指标.     

Reliability test of an electron cyclotron resonance ion source for accelerator driven sub-critical system

The reliability test of an electron cyclotron resonance ion source developed for accelerator driven sub-critical system is carried out in China Institute of Atomic Energy. A unique technique to improve the reliability is adopted. The source is operated for more than 200 h at 75 keV, 100 mA extracted hydrogen current, while 2 beam trips are recorded in the period, and uninterrupted operation time is about 150 h. The experimental result is described.     

Modernization of the injector for a multibeam proton accelerator

Within the program for the development of high-current charged-particle accelerators with a high acceleration rate, an injector for a 19-beam proton accelerator with a multibeam ion injection mode is described. The injector contains an ion gun with a duoplasmatron-type H₂ ion source and a multiaperture ion-optical system regulating the inclination of the ion-beam current tubes at the inputs of the corresponding channels of the accelerating structure. The cold-cathode ion source contains a system for transporting plasma from the cathode to its output aperture in magnetic fields of complex configurations, which allows stable pulsed generation of proton beams with a current amplitude of up to 3 A at an operating gas pressure in the discharge chamber of 0.2 Torr and a decrease in the flow of unionized gas emerging from the source to 2 cm³/h. It is shown that the developed ion source and the ion-optical system make it possible to increase the phase density of the beam current at the inputs of the accelerating-structure channels and to change the divergence angles.     

电子隧道加速度计输出信号的分析与处理

介绍了一种新型电子隧道加速度计的工作原理,详细分析了该加速度计输出信号的有效成分及噪声与干扰,设计了利用LabVIEW虚拟仪器开发平台的信号分析与处理程序.基于对电子隧道输出信号的分析,仿真了相应的模拟信号,并且通过对该模拟信号的软件处理,抑制了噪声,消除了工频干扰,将被噪声淹没的有效成分提取出来,从而证明了该方法的有效性.     

Interactions at the head–tape interface of a linear tape system

In this study, tape cycling experiments were performed using two different experimental metal particle media in combination with a Travan™ linear tape system. The aim was to investigate the effect of head/tape contact on the tribological properties and signal performance of the system. A combination of cycling at extreme environmental conditions, use of experimental media, and cycling beyond the normal limit of operation ensured a worst-case scenario for the head–tape interactions. Auger electron spectroscopy (AES) and atomic force microscopy (AFM) were used to characterize the chemical and physical surface changes that occurred on and in the head surfaces. X-ray photoelectron spectroscopy (XPS) was used to identify the chemical changes that occurred at the media surface and these changes were correlated to variation in signal dropout rate. Measurements were made as functions of number of cycles.The cycling experiments for the two different tapes were performed at conditions of 32°C, 80% RH and 5°C, 10% RH and transfer of material from the media to the head was observed at each condition for both tape types. The degree of material transfer was influenced by the environmental operating conditions, but was governed by localized heating effects, such as those originating from active magnetoresistive (MR) elements and frictional interactions between the head and media. XPS analyses of the surface of the media revealed a reduction of nitrogen with increasing number of cycles indicating binder depletion. Significant differences in elemental concentrations were also detected between areas corresponding to regions directly under the cartridge belt compared to those off belt.     

在线铁谱仪磁场的优化设计

提出了一种适用于在线铁谱仪磁场的优化设计方法。首先建立结合永磁体与电磁铁的混合磁铁模式,然后设计一种以磨粒所受磁力为依据的衡量磁场性能的目标函数,再采用改进遗传算法和有限元方法对混合磁铁进行了优化设计。以优化结果为依据研制了混合磁铁,并进行了实验测试。结果表明,与磁感应强度相比,所提出的目标函数更适合判断铁谱仪磁场的性能;混合磁铁满足在线铁谱仪的功能要求,体积只有电磁铁的1/3。     

Influence of the supplied energy on electroerosion recovery of material in an electrotechnical accelerator

The effect of the energy on the dynamics of electroerosive surface wear of the accelerating channel in a coaxial magnetic plasma accelerator is studied. The energy supplied to the accelerator is varied by cutting off the current pulse tail by a trigatron arrester at different instants of times. It has been ascertained that the dynamics of electroerosive surface wear of the accelerating channel is mainly determined by the behavior of the discharge power in the course of the process in the accelerator.     

Magnetic tracker calibration for an augmented reality system for therapy

Magnetic trackers are widely used position/orientation measurement devices in interactive computer systems. These trackers output six-degree-of-freedom position and orientation of their receiver coordinates with respect to their transmitter coordinates. It is a potential solution for real-time position/orientation measurement in an augmented reality system for therapy (ART). However, an obstruction to be overcome is that a magnetic tracker is vulnerable to measurement inaccuracy caused by magnetic field distortions (including ferric and non-ferric distortions) when it is used in metallic environments. The purpose of this paper is to discuss calibration methods used to compensate distortions produced by metallic objects which are moving during the measurement procedure, but fixed with a receiver. Past work on the calibration of magnetic trackers has concentrated on static distortions, which are produced by stationary metallic objects in the environment. Compared with static distortions, in this paper a relatively dynamic situation is considered where the distortion is not constant with time. However, the location of the metallic objects is reflected in the outputs of the receiver so that the distortion can be compensated. This type of distortions, which is called 'quasi-static distortion' in this paper, is common in an ART. Compensation of quasi-static distortion is more complicated than that of static distortion and has not been mentioned in past publications. Some new compensation methods for quasi-static distortion will be introduced here. The results demonstrate that the methods are capable of significantly reducing quasi-static distortions.