Linear Induction Accelerators for High-Power Microwave Devices

Igor Vintizenko

• Publisher: CRC Press
• Year: 2018
• Print ISBN: 9780367571382
• eBook ISBN: 9780429948640
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Chemistry
• Index: Chemistry

Linear induction accelerators are successfully used as power supplies for numerous devices of relativistic high-frequency electronics. This book addresses ways to solve physical and engineering problems arising in the calculation, design, modeling and operation of linear induction accelerators intended for supplying relativistic microwave devices. It reviews and analyzes both classic and recent studies on the topic of linear induction accelerators (LIA) for generating and amplifying microwave radiation by relativistic devices.

1

Principle of operation, construction and parameters of linear induction accelerators

1.1. Introduction

The development of high-voltage pulse accelerating technology started in the 60s of the last century and by now has achieved significant success. Intensive use is made of high-current electronic accelerators (HCEA), which allow producing high-energy particles at a sufficiently high efficiency of energy transfer from the power source to the beam. Beams of relativistic electrons are used in developing new methods of acceleration, searching for ways to implement controlled thermonuclear fusion, and also for generating bremsstrahlung and microwave radiation. At the same time, the maximum electron energy in HCEA is limited by the electrical strength of the system with respect to the total accelerating voltage.

To obtain powerful beams of charged particles, linear induction accelerators (LIA) are also actively used. For the first time the idea of LIA in the form of a system of successively installed impulse transformers was proposed in the early 1930s by A. Bouversey [1]. However, this idea was realized only after forty years, when the level of the development of physics and technology allowed us to achieve the required magnitude of the accelerating field. The first accelerators were created in the early 1960s in the USA under the guidance of N. Christofilos [2] in connection with the work on controlled thermonuclear fusion. One of the first large installations was an ‘Astron’ injector for 3.7 MeV energy and a beam current of 350 A in a 300 ns pulse [3]. Later, the accelerator was reconstructed, the energy was increased to 6 MeV, and the current to 500 A in a 300 ns pulse. The technique of LIA was especially successful in the 1970s and early 1980s. At this time, a number of large accelerators, such as ERA, ETA, FXR and ATA, for energy from 4 to 50 MeV and a pulsed beam current from 1 to 10 kA were built. In the USSR, in 1967, under the leadership of V. I. Veksler, the LIA-3000 for 3 MeV and a beam current of 200 A in a pulse was constructed to implement the collective acceleration method [4, 5] at The Joint Institute of Nuclear Physics (JINP) (Dubna) was built in cooperation with the NIIEFA (Leningrad) for the duration of 500 ns. Later on, a fundamentally new SILUND induction accelerator (a high-current induction linear accelerator of the nanosecond range) was created at Dubna, and in 1981 the SILUND-20 accelerator with a beam current of 1 kA, an electron energy of 2 MeV and a pulse repetition frequency of 50 Hz was put into operation. The pulse duration was approximately 20 ns, the emittance of the electron beam was about 3π cm · mrad for 60% of the current. In the 1970s, LIA-5000 (5 MeV, 2 kA, 50 ns) and the first section of the LIA 30/250 (3 MeV, 250 A, 500 ns) were constructed. The accumulated experience made it possible to proceed to the construction of technological installations. The first of them, LIA 1,25-200 and LIA 1-5, retained the main features of previous accelerators. They were made on the basis of small induction modules, powered from generators of high-voltage pulses, built on hydrogen thyratrons without the use of industrial transformers. They differed from each other in the type of material of the inductor cores (permalloy or ferrite) and the duration of the accelerating voltage pulse. Such accelerators began to be developed for research on the creation and retention of hot plasma, for experiments on the investigation of new methods for accelerating particles. In the 1980s, compact LIAs based on generators with magnetic compression were developed, which made it possible to increase the pulse repetition frequency up to several kHz [6]. It is hoped that, along with the increasing application of LIA in scientific research, they will be used in industry. For example, the LIA can be used as a basis for constructing mobile, cheap and easy-to-use installations for X-ray analysis, gamma-ray logging, flaw detectors, capable of operating in field or factory conditions can be created. Since the end of the 1980s linear induction accelerators have been applied as power sources for relativistic high-frequency devices [7, 8].

A few words should be said about the collective methods of acceleration, since in the USSR they served as the basis for the development of the technique of LIAs. The collective methods of acceleration occupy a leading place among the new effective methods of accelerating the contaminated particles. Many scientific centres of the world are carrying out experimental studies on various modifications of the collective method, facilities are being created, new concepts of acceleration are emerging, and accelerators of the future are being designed for higher energies [5]. The incentives for the development of collective methods were the proposals of Soviet physicists G.I. ...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Introduction
• 1. Principle of operation, construction and parameters of linear induction accelerators
• 2. Linear induction accelerators of the Tomsk Polytechnic University
• 3. Relativistic microwave devices with the electron beam formed by the linear induction accelerator
• 4. Relativistic magnetron microwave generators powered by linear induction accelerators
• 5. Generators of microsecond pulses
• Index