High power induction linac for FEL applications at CESTA

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 304; no. 1; pp. 368 - 370
• Main Authors: Launspach, J., Angles, J.M., Angles, M., Anthouard, P., Bardy, J., Bonnafond, C., Bottollier-Curtet, H., Devin, A., Eyharts, P., Eyl, P., Gardelle, J., Germain, G., Grua, P., Labrouche, J., de Mascureau, J., Le Taillandier, P., Stadnikoff, W., Thevenot, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.1991
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/0168-9002(91)90888-W

The purpose of the LELIA program developed at CESTA is to acquire the knowledge on induction accelerator technology for high peak power FEL applications. In a first step we study basic technology: (1) A high voltage pulse generator (150 kV, 60 ns, 2 ω) has been designed to drive the induction injector and the accelerating cells. It is able to work at high repetition rate (typically 1 kHz) by the use of magnetic switches. A flat top of 130 kV with ΔV V = ±0.8% has been obtained for about 50 ns. (2) An induction cell prototype has been built in order to check technological choices (vacuum, mechanics, magnetic guiding, voltage supply, etc.) for injector and accelerating modules. (3) The injector geometry is being studied using Euphrosyne (a classical intense relativistic electron beam device) which consists of a concave thermo-ionic oxide cathode, an intermediate electrode and a hollow anode with a magnetic guiding channel. This diode delivers an electron beam between 1 and 3 MV, about 1 kA and a flat top pulse during 20 ns. We will carry on the injector studies with our induction injector LELIA I (1.5 MV, 1.5 kA, 1 kHz) which will be available at the end of 1990. An accelerating module is also being designed, taking into account guiding and stability problems. All these points are described in more detail in a poster paper [J. Bardy et al., these Proceedings (12th Int. FEL Conf., Paris, France, 1990) Nucl. Instr. and Meth. A304 (1991) 311]. The main goal is to build a 10 MV, 1–3 kA, 1 kHz induction accelerator and to have it running at CESTA in 1993. On the other hand, we want to use the electron beam provided by Euphrosyne then in LELIA I to perform FEL experiments at 35 GHz using a bifilar helical wiggler [H. Bottollier-Curtet et al., these Proceedings, p. 197].