Design and Misalignment Analysis of 140 GHz, 1.5 MW Gyrotron Interaction Cavity for Plasma Heating Applications

In this paper the design of 140 GHz, 1.5 MW gyrotron interaction cavity is described in detail. The interaction cavity is designed and simulated by using Particle-in-Cell code for TE_24,8 operating mode. The obtained simulation results show more than 1.5 MW of output power at 139.83 GHz of frequency. A thorough parametric and misalignment study is also presented to support the actual fabrication and assembling of the device.     

Numerical Analysis of Interaction Cavity for 1.5 MW/127.5 GHz Gyrotron

This paper presents the design of 127.5 GHz ITER start-up gyrotron interaction cavity. Particle-in-Cell electromagnetic simulation approach has been used for the cold cavity and beam-wave interaction analysis. In-house developed code GCOMS has been used for the mode selection. TE_24,8 mode has been chosen as the operating mode. The simulation results show the output power more than 1.5 MW at the operating frequency of 127.8 GHz and the cavity centre magnetic field of 5.1 T. The study of the parametric dependency of the output power and the efficiency on the electron beam and the cavity geometry parameters has also been carried out.     

Improved Design of Beam Tunnel for 42 GHz Gyrotron

In gyrotron, there is the chance of generation and excitation of unwanted RF modes (parasite oscillations). These modes may interact with electron beam and consequently degrade the beam quality. This paper presents the improved design of the beam tunnel to reduce the parasite oscillations and the effect of beam tunnel geometry on the electron beam parameters. The design optimization of the beam tunnel has been done with the help of 3-D simulation software CST-Microwave Studio and the effect of beam tunnel geometry on the electron beam parameters has been analyzed by EGUN code.     

Design of 84 GHz 500 kW Gyrotron for Technological Millimeter Wave Applications

In this paper, the design and the numerical simulation of the 84 GHz, 500 kW gyrotron at first harmonic operation for technological applications is described. The operating mode of the gyrotron is TE_{10, 4}. Various in-house developed and commercially available computer codes are used for the design purpose. The triode-type magnetron injection gun with the accelerating voltage 70-kV, the beam current 10-A and the maximum transverse velocity spread less than 5% is designed. The preliminary design is obtained by using some trade-off equations. The mode selection, the cold cavity and the beam-wave interaction analysis are discussed for the design of weakly tapered open resonator type of the interaction cavity. The parametric analysis of the interaction cavity and the electron gun is also presented.     

Numerical Design of Megawatt Gyrotron with 120 GHz Frequency and 50% Efficiency for Plasma Fusion Application

The design of 120 GHz, 1 MW gyrotron for plasma fusion application is presented in this paper. The mode selection is carried out considering the aim of minimum mode competition, minimum cavity wall heating, etc. On the basis of the selected operating mode, the interaction cavity design and beam-wave interaction computation are carried out by using the PIC code. The design of triode type Magnetron Injection Gun (MIG) is also presented. Trajectory code EGUN, synthesis code MIGSYN and data analysis code MIGANS are used in the MIG designing. Further, the design of MIG is also validated by using the another trajectory code TRAK. The design results of beam dumping system (collector) and RF window are also presented. Depressed collector is designed to enhance the overall tube efficiency. The design study confirms >1 MW output power with tube efficiency around 50% (with collector efficiency).     

28 GHz Gyrotron ECRH on LDX

A 10 kW, CW, 28 GHz gyrotron has been implemented on LDX to increase the plasma density and to more fully explore the potential of high beta plasma stability in a dipole magnetic configuration. This added power represents about a 60% increase in ECRH to a new total of 26.9 kW with sources at 2.45, 6.4, and 10.5 GHz. The 1 Tesla resonances in LDX form small rings encompassing the entire plasma cross-section above and below the floating coil (F-coil) near the dipole axial region. A 32.5 mm diameter TE₀₁ waveguide with a partial Vlasov step cut launches a diverging beam from above the F-coil that depends on internal wall reflections for plasma coupling. Initial gyrotron only plasmas exhibit steep natural profiles with fewer hot electrons than with the other sources. The background scattered radiation suggests that only about half the power is being absorbed with the present launcher.     

Polarization and Mode Control of EAST 140 GHz ECRH&CD System

The 140 GHz electron cyclotron heating and current drive (ECRH&CD) project was launched in 2011 on EAST tokamak facility, which is designed to launch 4 MW of total power for the duration up to 1,000 s into the plasma. The heating and current drive efficiencies depend on the wave coupling mode in plasma and the coupling performance relies on polarization characteristics of injected beam, so polarization control is necessary for efficient plasma heating and current drive. Two polarizer miter bends will be used to control the wave polarization for each transmission line on EAST ECRH&CD system, any required wave polarization can be produced by adjusting the mirror rotation angle of each polarizer miter bend. This work mainly shows the calculated polarizer mirror settings as a function of the injection angles for pure second extraordinary harmonic mode coupling.     

Beam Scan System Design of 350 keV High-voltage Electron Accelerator

A 350 keV 21 kW high-voltage electron accelerator was developed for irradiation of industryproducts. The accelerator was equipped with the electron irradiation field shaping system with an elongated turning magnet allowing an irradiation field up to 850 m…     

Design, Machining and Installation of Injection Line of CRM for CYCIAE-100

For the central region model （CRM） of CYCIAE-100, the 100 MeV high intensity cyclotron under design at CIAE, the injection energy is 30 keV; the transverse focusing elements used are one solenoid and two quadrupoles. There are two considerations about axial injection line for CRM, one case with bunchers and the other without bunchers. The optic layout is shown in Fig. 1.     

Design,Machining and Installation of Injection Line of CRM for CYCIAE-100

For the central region model (CRM) of CYCIAE-100, the 100 MeV high intensity cyclotron under design at CIAE, the injection energy is 30 keV; the transverse focusing elements used are one solenoid     

Design of Cooling-Water System for Bi-Energy Linactron

Cooling-water system is the leading and necessary auxiliary equipment of accelerator. Heat generated by a multitude of accelerator components is absorbed by circular cooling-water in this system. Then the components are cooled and the accelerator will work normally. This article mainly introduced     

Design of Cooling-Water System for Bi-Energy Linactron

有效地鉴别同量异位素是实现AMS技术的高灵敏、高精度测量的关键。Bragg曲线探测器具有相对较高的能量分辨本领，因此，利用Bragg线探测器在AMS测量中进行同量异位素的鉴别将提高AMS测量中对中重核素同量异位素的鉴别能力，为开展AMS长寿命中重核测量提供重要技术手段。本工作对电子信号的获取方式，工作气压，阴极网和流气速度等重新进行了系统测试与改进。     

Reference Design of ICRF Antenna for EAST

An antenna array suitable for plasma heating and current drive has been designed for the ion cyclotron resonance frequency range （ICRF） heating on the EAST superconducting tokamak. The ICRF heating is planned to operate in a frequency range of 30 MHz to 80 MHz and hence the antenna geometry is optimized for 55 MHz. The design is based on the conventional strap antenna element. The coupling properties of the antenna are calculated with a slab model of the plasma for the antenna simulation. The coupling code is extended for the analysis of the toroidal antenna array separated by septa.