High-current micro-pulse electron guns and accelerator applications

Abstract

A major research activity is being pursued at FMT to develop high-current, short-duration pulses of electron beams for injectors in electron accelerators as well as for microwave generation in klystrons and related devices. Design and development of gun cavities, in the frequency range of 1 to 12 GHz, are conducted through a comprehensive task including simulation, analytical and experimental studies. With the goal to build high-power, high-frequency klystrons, one of our most recent efforts is focused on developing an X-band cavity at about 9 GHz for generating high-current, bunched micropulses of electron beams. The full system has been designed and built, and it is running reliably. An average beam current density > 20A/cm 2 over a macropulse, or 400 A/cm 2 over a micropulse, has been measured for a modest input rfpower, ~60 kW, into the gun cavity. In addition, experiments are being conducted to develop an electron gun at 1.3 GHz, with gating capabilities, and match beam requirements for Argonne Wakefield Accelerator.

Novel particle and radiation sources and advanced materials

“…However, FMT has found a unique device for the utilization of multipacting that improves accelerator and microwave tube designs. The Micro-Pulse Gun (MPG) [10][11][12][13][14][15] exploits secondary electron emission and more specifically multipacting to form a narrow self-bunching RF fed electron gun. Figure 3 is a schematic of an RF cavity operating in, for example, a TM 010 mode.…”

Theoretical analysis and simulation of the influence of self-bunching effects and longitudinal space charge effects on the propagation of keV electron bunch produced by a novel S-band Micro-Pulse electron Gun

“…Some applications of the multipacting effect require to suppress the secondary-electron emission while the others such as crossed-field devices, need to enhance the emission. 8 Micro-Pulse electron Gun (MPG) which was proposed and developed by Mako [9][10][11][12] needs to select the materials judiciously. Actually, the Multipactor Electron Gun (MEG) which is essentially the same to MPG has been deeply studied.…”