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.     

LIU-2 linear induction accelerator

The LIU-2 induction accelerator is described. It is used as an injector for the developed large linear induction accelerator with a maximum electron beam energy of 20 MeV, which is intended for smallangle pulse X-ray tomography. Owing to the good quality and high current of the electron beam (2 kA), the injector is capable of operating as an independent X-ray source with an electron energy of 2 MeV, the beam diameter at the target of <2 mm, and a pulse duration of 200 ns. The total yield of the bremsstrahlung energy is 52.4 J and the fraction of quanta with energies of >1 MeV is ～20% of the total energy yield. The spread of the radiation intensity in the solid angle of 10° is ±5%, and the absorbed dose at a distance of 1 m from the target is 32 × 10^?3 Gy, which allows this source to be used with attenuation of 10³–10⁴ for exposure of available X-ray films. This type of system is characterized by a high transmission capability with a 0.5-mm maximum spatial resolution of X-ray images and can be used in the X-ray imaging technique when carrying out gas-dynamic testing of products with an optical thickness as great as 90 mm of lead equivalent.     

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.     

A novel design of active accelerator pedal using linear electromagnetic actuator

This paper describes a novel design of an active accelerator pedal(AAP) using a linear electromagnetic actuator that transfers warning messages recognized by the automobile from the sensors to the driver. In an emergency driving situation, the electromagnetic actuator creates additional pedal forces such as active pedal force and vibration force. In a passive situation however, the actuator does not produce additional force. In the past, a system with a rotary actuator was developed for AAP but was found to have critical drawbacks such as inaccurate movement by backlash and torque occurrence due to the high gear ratio. This research, therefore, aims to solve these drawbacks and maximize car safety by optimizing the electromagnetic linear actuator. Finite element analysis is performed to analyze the coupled system of electric, magnetic, and mechanical subsystems, and to characterize the dynamic performance of the proposed actuator system. A novel design of the AAP system with the optimized electromagnetic linear actuator is developed. The dynamic characteristics of the AAP system are simulated by a 3D dynamic analysis software program. Satisfactory results were obtained. Finally, the test result and the simulation result of the AAP system are compared.     

Development of compact linear accelerator in KBSI

The compact linear accelerator using a 28 GHz ECRIS is under construction in KBSI, South Korea. The main capability of this facility is the production of fast neurons for the neutron radiography. The designing of a superconducting magnet, microwave transmission system, beam extraction, and plasma chamber of ECRIS were finished. The nominal axial design fields of the magnets are 3.6 T at injection and 2.2 T at extraction; the nominal radial design field strength at the plasma chamber wall is 2.1 T. We already installed 10 kW, 28 GHz gyrotron, and tested a microwave power from gyrotron using a dummy load. The current status will be discussed in this paper.     

电子直线加速器与电子感应加速器的比较

现代工业是建立在无损检测基础之上的说法并非言过其实。无损检测技术经历一个世纪的发展,尽管它本身并非一种生产技术,但其技术水平反映了该部门、该行业、该地区甚至该国家的工业技术水平。无损检测的仪器种类很多,大致分为超声、射线、涡流、磁粉等。能产生高能X射线的电子直线加速器由于射线能量高,能对大型部件和厚金属材料进行探伤,它产生的韧致辐射强度比电子感应加速器高几十到几百倍,同时,射线照相所需时间更短,分辨率更高。     

An ILU-8 pulsed high-frequency electron linear accelerator

An ILU-8 single-cavity electron linear accelerator has been designed for use in industrial radiation technology systems for electron irradiation of materials and products. Experimental data of accelerator adjustment and results of measurements of the accelerated beam parameters in modes characteristic of industrial applications are presented. The main parameters of the accelerator are as follows: the electron energies are 0.7–1.0 MeV and the beam power is 20 kW at an average current of up to 25 mA. The accelerator operates in a pulsed mode: the pulse duration is 800 μs, and the pulse repetition frequency is 50 (60) Hz. The cavity is excited by a single-stage self-excited oscillator based on a GI-50A tube with feedback via the cavity at a frequency of 175.6 MHz. The accelerating cavity, together with a system of beam extraction into the atmosphere, can be located inside the biological shielding composed of steel slabs with a total mass of 76 t.     

12MeV驻波电子直线加速器自动频率控制技术设计

本文讨论了用于1 2MeV驻波电子直线加速器的自动频率控制技术及其实现方法.     

医用直线加速器自动摆位系统设计

研发一套自动摆位系统以提高放射治疗摆位的精度和效率。该摆位和传送装置,可实现患者自动摆位,并在患者治疗结束后,通过传送装置将其送出机房,同时将下一个需要治疗的患者送入机房。提高了放射治疗的精确性和医用直线加速器的工作效率,同时减小了技术人员的劳动强度和接受的辐射剂量。试验表明,本系统能提高医用直线加速器摆位的效率和精度,具有较高的临床应用价值。     

Low energy beam transport for facility for rare isotope beams driver linear particle accelerator

The driver linac for the facility for rare isotope beams (FRIB) will provide a wide range of primary ion beams for nuclear physics research. The linac will be capable of accelerating a uranium beam to an energy of up to 200 Mev∕u and delivering it to a fragmentation target with a maximum power of 400 kW. Stable ion beams will be produced by a high performance electron cyclotron resonance ion source operating at 28 GHz. The ion source will be located on a high voltage platform to reach an initial beam energy of 12 keV∕u. After extraction, the ion beam will be transported vertically down to the linac tunnel in a low energy beam transport (LEBT) system and injected into a radio frequency quadrupole (RFQ) operating at a frequency of 80.5 MHz. To meet the beam power requirements, simultaneous acceleration of two-charge states will be used for heavier ions (≥Xe). This paper presents the layout of the FRIB LEBT and the beam dynamics in the LEBT. In particular, simulation and design of the beam line section before charge state selection will be detailed. The need to use an achromatic design for the charge state selection system and the advantage of an ion beam collimation system to limit the emittance of the beam injected into the RFQ will be discussed in this paper.     

12MeV驻波电子直线加速器的能量调变技术设计

本文讨论了影响12MeV驻波电子直线加速器能量调变的主要因素,实现能量调变的具体方法及其实例.     

Design and tuning of a 40-MeV electron linear accelerator

The 40-MeV electron linear accelerator RELUS-6 with a 100-mA pulse current has been designed. The standing wave accelerator with a biperiodic accelerating structure is composed of four sections and is powered from two 6-MW pulse klystrons. The operating frequency is 2856 MHz. The total length of the accelerating structure is 2.73 m. Calculations have been performed with the aim of selecting the lengths of the first three cells in the first accelerating section and the values of the accelerating field in them, so that the width of the energy spectrum at the end of the accelerator is 2%. The geometry of the accelerating structure and the power input cells has been designed. Four accelerating structures have been manufactured based on the simulation results. The structures have been tuned to the operating frequency, the predetermined accelerating field distribution, and a fixed coupling between the feed waveguide and the accelerating section.     

ILU-14 industrial electron linear accelerator with a modular structure

A new high-power (up to 100 kW) industrial electron linear accelerator ILU-14 for energies of 7.5–10.0 MeV has been developed by the Budker Institute of Nuclear Physics. The operating frequency of the accelerator is 176 MHz, and the total efficiency is 26%. Owing to the modular structure of the accelerator, the electron energy and the beam power can be varied within certain limits by changing the modular arrangement. A 5-MeV prototype of this accelerator has been produced and successfully tested. Its design parameters verified in the experiments are as follows: the beam current averaged over the RF period is 600 mA, the beam pulse power is 2.5 MW, and the electron efficiency of the accelerating structure is 68%. By applying an additional RF voltage to the electron gun cathode-grid gap, a 96% transmittance of the beam current has been attained at a minor beam energy spread. The prototype of the ILU-14 accelerator can be used as an accelerator with a beam power of 50 kW.     

12MeV无损检测用驻波电子直线加速器指标测试方法

研制12MeV无损检测用驻波电子直线加速器产品时,需要同时制定相关技术指标的测试方法,供测试时参考.     

12MeV无损检测用驻波电子直线加速器总体技术设计

本文主要讨论了12MeV无损检测用驻波电子直线加速器总体技术设计,主要部分的设计思路、要点及最终设计方案.     

A power supply for simulating lightning-current pulses

The circuit diagram of a power-supply unit for simulating a positive lightning on a system of grounding current pulses is presented. The main criteria that governed the development of this facility are expounded. The design and order of operation of an experimental specimen of a power supply developed at the VNIIEF on the basis of a BMΓ-320 cascade magnetic-cumulation generator are considered. A calculation technique is described with which a device for the formation of current pulses of up to 90 kA in a standard grounding system has been developed.     

Generation, transport, and detection of linear accelerator based femtosecond-terahertz pulses

The generation and detection of intense terahertz (THz) radiation has drawn a great attention recently. The dramatically enhanced energy and peak electric field of the coherent THz radiation can be generated by coherent superposition of radiated fields emitted by ultrafast electron bunches. The femtosecond (fs)-THz beamline construction at the Pohang Accelerator Laboratory (PAL) was completed in the end of 2009. The fs-THz beamline at PAL can supply ultrafast and intense fs-THz radiation from a 75 MeV linear accelerator. The radiation is expected to have frequency up to 3 THz (～100 cm(-1)) and the pulse width of <200 fs with pulse energy up to 10 μJ. This intense THz source has great potential for applications in nonlinear optical phenomena and fields such as material science, biomedical science, chemistry, and physics, etc.     

Applicability of a conical cavity as a target for generation of neutrons in a linear accelerator

Results of the study are presented, which demonstrate the applicability of targets with a tapered surface of the reaction layer for generation of neutrons in linear accelerators of hydrogen nuclides in the nuclear reactions T(d, n)⁴He, T(p, n)³He, and D(d, n)³He. An algorithm is proposed for calculating the neutron yield, taking into account possible changes in the concentration of hydrogen isotopes in the target with depth. As a result of computer simulations, the dependence of the neutron yield on the cone angle has been established, and the possibility has been shown of increasing the neutron yield from a target with a conical surface of its reaction layer without changing its thickness.