Radiation measurements in the new tandem accelerator FEL

The measurements of both spontaneous and stimulated emissions of radiation in the newly configured Israeli EA-FEL are made for the first time. The radiation at the W-band was measured and characterized. The results match the predictions of our earlier theoretical modeling and calculations.Comment: 4 pages, 3 figures, FEL 2003 Conference repor

SectIon A Free electron maser experiment with a prebunched beam

Abstract An experimental project aimed at demonstrating Free Electron Maser (FEM) operation with prebunching is under way at Tel-Aviv university. The FEM utilizes a 1.0 A prebunched electron beam obtained from a microwave tube. The electron beam is bunched at 4.87 GHz and is subsequently accelerated to 70 keV. The bunched beam is injected into a planar wiggler (B, = 300 G, A, = 4.4 cm) constructed in a Halbach configuration with 17 periods. The wiggler utilizes a new scheme for horizontal focusing based on the use of two long permanent magnets at the sides of the wiggler. We plan to study FEM gain enhancement and radiation features due to the prebunched (superradiant) mode of operation. In an oscillator configuration the experiment should be enable study of seed injection by prebunching. Simulation of FEL operation shows an expected gain of approximately 100% and an rf output power of 5 kW. In this paper we review the design of the main parts of the experimental set-up, and present recent analytical, numerical, and experimental results

First operation of the Israeli Tandem Electrostatic Accelerator Free-Electron Laser

Abstract Results of first operation of the Israeli Electrostatic-Accelerator Tandem Free-Electron Laser (EA-FEL) are reported. This EA-FEL utilizes a 1.4 A electron beam obtained from a parallel flow Pierce-type electron gun. The e-beam is transported into a resonator located inside a planar Halbach configuration wiggler, which is at a potential of 1.4 MeV with respect to the cathode. A resonator utilizing two curved parallel plates as a waveguide and two Talbot effect quasioptical reflectors (wave splitters) provides a quality factor Q + 30 000. Millimeter wave radiation pulses of 2 s duration were obtained at a frequency of 100.5 GHz, as predicted, at a power level above 1 kW. 1998 Elsevier Science B.V. All rights reserved