07 Accelerator Technology

T15 Insertion Devices

Paper	Title	Page
TUYFI02	Latest Developments on Insertion Devices	969
	P. Elleaume, J. Chavanne ESRF, Grenoble
	A review will be carried out of the developments on Insertion Devices that have taken place world wide in the last few years. These include the development of long period electro-magnet undulators, the operational results of a number of Apple-II undulators, the development of superconducting short period multipole wigglers, as well as the construction and operation of several in-vacuum undulators. The construction of a large number of competitive middle energy synchrotron sources in the hard X-ray range means that the need to increase the photon energy in the fundamental peak of an undulator is becoming a very important issue. Two main development strategies are currently being investigated. One consists of using superconducting undulator technology, the other of a further refinement of the in-vacuum undulator permanent magnet technology with cryogenic cooling of the magnetic assembly. The issues and challenges that are part of each approach will be presented, together with the latest results.
	Transparencies
THPCH132	EPU Assembly Based on Sub-cassettes Magnetic Characterization	3107
	G. Tosin, R. Basilio, J.F. Citadini, M. Potye LNLS, Campinas
	A procedure to speed up the magnetic field correction of an EPU type undulator is proposed and its results are shown. Such procedure consists in segmenting each one of the four magnetic blocks linear arrays (cassettes) in seven sub-cassettes and making their individual magnetic and mechanical characterization. One theoretical perfect sub-cassette, which is composed of four segments per period in Halbach configuration, is taken as the standard field profile. The peak fields and the fields integrated in each semi-period of one sub-cassette are chosen to be the optimization parameters. The magnetic blocks are displaced (virtual shims) to minimize the difference of the optimization parameters between the sub-cassette magnetic measurement and the standard profile. The sub-cassette magnetic measurements are performed with Hall probes, using the same bench employed in insertion devices characterization.
THPCH133	Conceptual Design of an EPU for VUV Radiation Production at LNLS	3110
	G. Tosin, R. Basilio, J.F. Citadini, R.T. Neuenschwander, M. Potye, X.R. Resende, M. Rocha, P.F. Tavares LNLS, Campinas
	We describe the magnetic and mechanical design of an elliptically polarizing undulator (EPU) currently under construction at the (Brazilian Synchrotron Light Source - LNLS). The device is designed to cover the photon flux in the range from 100eV to 1000eV (124Å a 12.4 Å), allowing linear, elliptical and circular polarizations. With this device it is possible to reach absorption edges of several elements such as Si, S, Br, C, N, O, Fe, F, Cl and to measure magnetic dichroism. The EPU's magnetic design is conventional, and field corrections are done by means of virtual shims, with horizontal and vertical displacements. Each one of the four magnetic blocks linear arrays (cassettes) is segmented in seven sub-cassettes. The separate magnetic measurement of each sub-cassette allows corrections of the magnetic field profile to be made before final assembly and makes the verification of mechanical tolerances easier and faster, decreasing the expected time that will be spent in the magnetic tuning of the device. The mechanical structure is composed of a C-Frame, gap and phase actuators. The gaps actuators and phase actuators use absolute encoders and bias with springs to eliminate backlash.
THPCH134	Development of Insertion Device Magnetic Characterization Systems at LNLS	3113
	G. Tosin, R. Basilio, J.F. Citadini, M. Potye LNLS, Campinas
	This paper describes a set of magnetic measurement systems employed in the development of insertion devices at LNLS (Brazilian Synchrotron Light Source). They are: rotating coil (which can also operate as a flip-coil), spatial field mapping using Hall probes and parallel coils (Helmholtz configuration) for magnetic blocks characterization. Although such techniques are well established, strict specifications imposed by the beam dynamics on the magnetic field quality, led to a detailed analysis of their sources of error and their minimization. All three systems have already been tested and showed excellent accuracy and repeatability when compared to typical values found in the literature.
THPCH135	65 MEV Neutron Irradiation of ND-FE-B Permanent Magnets	3116
	X.-M. Maréchal, T. Bizen JASRI/SPring-8, Hyogo-ken Y. Asano JAEA/SPring-8, Hyogo H. Kitamura RIKEN Spring-8 Harima, Hyogo
	Rare-earth permanent magnets are now playing a major role in accelerator technology, from the development of beam transport systems magnets to their extensive use in synchrotron radiation sources and free electron lasers. Unfortunately, operating in a high radiation environment, rare-earth permanent magnets are subject to demagnetization caused by direct and scattered radiation. The lifetime of these components is therefore a major issue: as a result, the number of studies to clarify the demagnetization mechanism or to test materials of interest for a particular application under specific conditions of irradiation has increased in recent years. However, so far, neutron irradiation experiments have been mainly carried out with reactors, were neutrons have a wide, but mainly low, energy spectrum. We present here the results obtained at the TIARA facility of the Japan Atomic Energy Research Institute, a spalliation source of mono highly energetic neutrons. Four types of Nd-Fe-B permanent magnets (Neomax™ 35EH, 32AH, 27VH and 44H) representing a wide range of characteristics (remanence and coervicity) have been studied.
THPCH171	Control System of the Superconducting Insertion Device at TLS	3197
	J. Chen, K.-T. Hsu, S.Y. Hsu, K.H. Hu, C.H. Kuo, D. Lee, C.-J. Wang NSRRC, Hsinchu
	There are three superconducting insertion devices installed at Taiwan Light Source. Two is under construction. These insertions enhance hard X-ray production to satisfy the research requirement of X-ray community. The control system is implemented to support the operation of all these superconducting insertion devices. The control system coordinate the operation of the main power supply and the trimming power supply to charge/discharge the magnets and provide essential interlock protection for the coils and vacuum ducts. Friendly user interface supports routine operation. Various applications are also developed to aid the operation of these insertion devices. Design consideration and details of the implementation will be summary in this report.