CERN 98-04 3 August 1998 KSOO2373432 R: KS DE011946929 ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CERN ACCELERATOR SCHOOL SYNCHROTRON RADIATION AND FREE ELECTRON LASERS President Hotel, Grenoble, France 22-27 April 1996 PROCEEDINGS Editor: S. Turner GENEVA 1998 CERN-Service d'information scientifique-RD/982-150O-August 1998 © Copyright CERN, Genève, 1997 Propriété littéraire et scientifique réservée Literary and scientific copyrights reserved in all pour tous les pays du monde. Ce document ne countries of the world. This report, or any part peut être reproduit ou traduit en tout ou en of it, may not be reprinted or translated partie sans l'autorisation écrite du Directeur without written permission of the copyright général du CERN, titulaire du droit d'auteur. holder, the Director-General of CERN. Dans les cas appropriés, et s'il s'agit d'utiliser However, permission will be freely granted for le document à des fins non commerciales, cette appropriate non-commercial use. autorisation sera volontiers accordée. If any patentable invention or registrable design Le CERN ne revendique pas la propriété des is described in the report, CERN makes no inventions brevetables et dessins ou modèles claim to property rights in it but offers it for the susceptibles de dépôt qui pourraient être free use of research institutions, manu- décrits dans le présent document; ceux-ci peu- facturers and others. CERN, however, may vent être librement utilisés par les instituts de oppose any attempt by a user to claim any recherche, les industriels et autres intéressés. proprietary or patent rights in such inventions Cependant, le CERN se réserve le droit de or designs as may be described in the present s'opposer à toute revendication qu'un usager document. pourrait faire de la propriété scientifique ou industrielle de toute invention et tout dessin ou modèle décrits dans le présent document. ISSN 0007-8328 ISBN 92-9083-118-9 Ill *DE011946929* XC98F«173~ ABSTRACT These proceedings present the lectures given at the tenth specialised course organised by the CERN Accelerator School (CAS), the topic this time being 'Synchrotron Radiation and Free-electron Lasers'. A similar course was already given at Chester, UK in 1989 and whose proceedings were published as CERN 90-03. However, recent progress in this field has been so rapid that it became urgent to present a revised version of the course. Starting with a review of the characteristics of synchrotron radiation there follows introductory lectures on electron dynamics in storage rings, beam insertion devices, and beam current and radiation brightness limits. These themes are then developed with more detailed lectures on lattices and emittance, wigglers and undulators, current limitations, beam lifetime and quality, diagnostics and beam stability. Finally lectures are presented on linac and storage ring free-electron lasers. CERN RCCELERRTOR SCHOOL EUROPERN SVNCHROTRON RRDIRTION FRCILITV will Jointly organise a course on SVNCHROTRON RRDIHTION & FREE-ELECTRON LRSERS 22-27 flpril 1996 President Hotel, Grenoble, France PROGRAMME OF THE COURSE SYNCHROTRON RADIATION AND FREE-ELECTRON LASERS Hotel President, Grenoble, 22-27 April, 1996 Time Monday Tuesday Wednesday Thursday Friday Saturday 22 April 23 April 24 April 25 April 26 April 27 April 09.00 Opening Talk Lattices and Lattices and Lattices and Linac FELs Linac FELs A user's view emittance emittance emittance I II of synchrotron I II III radiation 10.00 Y. Petroff A. Ropert A. Ropert A. Ropert M. Poole M. Poole COFFEE 10.20 Introduction to Wigglers and Wigglers and Lifetime and Storage ring Storage ring physics of undulators undulators beam quality FELs FELs synchrotron I II II I II radiation 11.20 A. Hofmann R. Walker R. Walker C. Bocchetta R. Bakker R. Bakker M I D-MORNING BREAK 11.30 Introduction to Current Current Wigglers and Beam stability Seminar dynamics of limitations limitations undulators Industrial and electrons in I II III medical rings applications 12.30 L. Rivkin S. Myers S. Myers R. Walker L. Farvacque I. Munro LUNCH 14.00 Introduction to Tutorial VISIT Tutorial Tutorial insertion TO THE devices ESRF 15.00 K. Wille BREAK BREAK 15.10 Introduction to Lifetime and Lifetime and Poster current and beam quality beam quality session brightness I III limits 16.10 V. Suller C. Bocchetta C. Bocchetta TEA TEA 16.30 Seminar Diagnostics Diagnostics HS e m i n a r Scientific I II Practical applications aspects of beam stability 17.30 D. Hauserman A. Hofmann A. Hofmann P. Quinn WELCOME COCKTAIL EVENING MEAL DINNER EVENING BANQUET at the Chateau MEAL de Sassenages ^* 43 r ^** & ' /HIM « *** AS s, 4i> ^ s '"• ' "* --' ^ . '„„* •_• ,J ,V . , ' *J i i -^ v 1 _ _ i> j j ui • • • _ & & _ _ _ _ _ M $ •_ _ Vll FOREWORD The aim of the CERN Accelerator School to collect, preserve and disseminate the knowledge accumulated in the world's accelerator laboratories applies not only to accelerators and storage rings, but also to the related sub-systems, equipment and technologies. This wider aim is being achieved by means of the specialised courses listed in the Table below. The latest of these was on the topic of Synchrotron Radiation and Free-electron Lasers and was held at the President Hotel, Grenoble, France, 22-27 April 1996, its proceedings forming the present volume. Synchrotron radiation has become one of the most valuable and useful scientific tools with ever increasing applications for basic and applied research especially in the biotechnology, chemical, material and pharmaceutical fields. This can be seen by the recent rapid increase in the number of sources widely distributed around the world and in the intensity of the radiation they produce. While initially synchrotron radiation was a by-product of high-energy accelerators, the recent so-called third generation sources are specifically designed to produce very intense photon beams by using low-emittance storage rings with high beam currents together with insertion devices. With such enormous progress in the design of sources and in their range of applications, there was an urgent need to present an updated version of the course first presented in 1989. Not forgetting the basic theory of synchrotron radiation and electron synchrotrons, introductions are given to insertion devices and to the limitations to beam currents and radiation brightness. These topics are then developed before turning to linac and storage-ring free- electron lasers. This course was only made possible by the generous support of several laboratories and many individuals. In particular, the help and encouragement of the ESRF management and staff, especially J.-L. Laclare, A. Ropert and T. Bouvet, was most invaluable. As always, the support of the CERN management, the guidance of the CAS Advisory and Programme Committees, and the attention to detail of the Local Organising Committee and the management and staff of the President Hotel ensured that the course was held under optimum conditions. Very special thanks must go to the lecturers at this course for the enormous task of preparing, presenting and writing up their topics. Finally, the enthusiasm of the participants, coming from so many parts of the world, was a convincing proof of the usefulness and success of this course. S. Turner, Editor Vlll LIST OF SPECIALISED CAS COURSES AND THEIR PROCEEDINGS Year Course Proceedings 1983 Antiprotons for colliding beam facilities CERN 84-15 (1984) 1986 Applied Geodesy for particle accelerators CERN 87-01 (1987) also Lecture Notes in Earth Sciences 12, (Springer Verlag, 1987) 1988 Superconductivity in particle accelerators CERN 89-04 (1989) 1989 Synchrotron radiation and free-electron lasers CERN 90-03 (1990) 1990 Power converters for particle accelerators CERN 90-07 (1990) 1991 RF engineering for particle accelerators CERN 92-03 (1992) 1992 Magnetic measurement and alignment CERN 92-05 (1992) 1993 RF engineering for particle accelerators (repeat of the 1991 course) 1994 Cyclotrons, linacs and their applications CERN 96-02 (1996) 1995 Superconductivity in particle accelerators CERN 96-03 (1996) 1996 Synchrotron radiation and free-electron lasers Present volume IX CONTENTS Page no. Foreword Y. Petroff A user's view of synchrotron radiation Contribution not received A. Hofmann Characteristics of synchrotron radiation 1 Qualitative treatment of synchrotron radiation 1 Potentials and fields of a moving charge 5 Radiation from a charge moving on a circular orbit 15 Undulator radiation 30 L. Rivkin Introduction to dynamics of electrons in rings in the presence of radiation 45 Introduction 45 Radiation effects in electron storage rings 45 Synchrotron oscillations 47 Damping of betatron oscillations 52 Adjustment of damping rates 54 Quantum fluctuations - equilibrium beam sizes 55 K. Wille Introduction to insertion devices 61 Introduction 61 Wiggler and undulator field 63 Equation of motion in W/U-magnets 67 Undulator radiation 71 V. Sutler Introduction to current and brightness limits 77 Introduction 77 Beam current measurement and typical values 77 Fourier components of the beam current 79 Fields of relativistic electrons 80 Effects due to the vacuum chamber walls 83 Brightness of a synchrotron radiation source 85 Brightness limitations 89 A. Ropert Lattices and emittances 91 From high brilliance to low emittance 91 Low-emittance lattices 93 Lattice types 96 Problems associated with low-emittance lattices 105 Effects of insertion devices on the beam 113 Conclusions 126 R. Walker Insertion devices: