U.S. Particle Accelerator School

Vacuum Electron Devices course

Sponsoring University:

University of Maryland


Vacuum Electron Devices


Alain Durand, Thales Electron Devices and Michel Langlois, ALBA Synchrotron

Purpose and Audience
This course will provide all the necessary physics and engineering on how Vacuum Electron Devices work and how to use them in amplifiers for accelerators. The course is dedicated to engineers and physicists who are using VED amplifiers or planning to use such equipment.

After the course, the student will understand (i) the basic operating principles of Vacuum Electron Devices, particularly gridded devices, klystrons and Inductive Output Tubes (IOT), (ii) the criteria to select the right technology and the right device, and (iii) the way to integrate such device in an amplifier and to combine devices to get the required powers.

Instructional Method
The course will consist of 25 hours of lectures during the morning and afternoon, focusing on the theoretical understanding of the course content, as well as sessions on how to calculate the different parameters. Daily homework will be given that lets the student review basic concepts introduced in class.

Course Content
The course will cover from electronic emission to device implementation, from a theoretical understanding to an engineering implementation of Vacuum Electron Devices. The first topic will focus on device technology: emission of electrons from different types of cathodes, grids, anodes, vacuum pumping process, high efficiency cooling, and materials required to fulfill device characteristics. The second topic will go through device design and operation in order to address the different possible choices and the selection criteria. Calculations of the device characteristics will also be investigated. The third aspect will be dedicated to device implementation in a full amplifier, including for gridded devices (tetrodes and IOT), the definition of the required cavities, the load matching techniques and the necessary tuning. At the end of the course the student will be in a position to understand the various Vacuum Electron Devices technologies, to select the right tube for his applications, to determine the different necessary equipment to be added to the device and to calculate the performance of his final amplifier.

Reading Requirements
Instructor-provided handouts.

Credit Requirements
Students will be evaluated based on performance: homework (30% of final grade), final exam (40% of final grade), and Vacuum Electron Device calculation during course (30% of final grade).