XFEL

Paper	Title	Other Keywords	Page
MOXPA02	SCRF Test Facilities toward the ILC	TTF, KEK, DESY, linac	5
	K. Saito KEK, Ibaraki
	After the ICFA selection of the superconducting linear collider technology in August 2004, many intensive R&D programs are in the planning stage or already underway. Work is proceeding in the three major geographical regions involved in the ILC: Europe(TTF), North America (SMTF) and Asia (STF). In this paper, the global activity represented by these superconducting RF test facilities will be reviewed. Their goals, plans, schedules and possible complementarities will be presented. The performance expected from the different R&D efforts by 2008, and the corresponding contribution to the ILC Technical Design Report, will be especially emphasized.
	Transparencies
MOPLS104	The Progress in Developing Superconducting Third Harmonic Cavity	DESY, simulation, coupling, TTF	804
	N. Solyak, H. Edwards, M. Foley, I.G. Gonin, E.R. Harms, T.K. Khabiboulline, D.V. Mitchell, D.O. Olis, A.M. Rowe Fermilab, Batavia, Illinois
	XFEL and TTF facilities are planning to use section with a few third harmonic cavities (3.9GHz) upstream of the bunch compressor to improve beam performances [1-2]. Fermilab is developing superconducting third harmonic section for TTFII upgrade. This section will include four cavities equiped with couplers and blade tuners, installed in cryostat. Up to now, two cavities are complete and one of them is under test. The status of the cavity development and preliminary test results are presented in the paper.
TUPCH116	Waveguide Distribution Systems for the European XFEL	DESY, klystron, linac, coupling	1286
	V.V. Katalev, S. Choroba DESY, Hamburg
	In the European X-ray FEL 32 superconducting cavities are connected to a 10 MW multibeam klystron through a waveguide distribution system. The basic waveguide system is a linear system. The XFEL tunnel has limited space for the waveguide system and therefore some new compact high power waveguide components like a motor driven phaseshifter, an iris tuner and an asymmetric shunt tee have been developed. Also alternative layouts of the waveguide distribution system which may have certain advantages have been designed. In this report we will present the different layouts and report on the status of the development of the different new waveguide components.
TUPCH136	Phase Measurement and Compensation System in PLS 2.5 GeV Linac for PAL-XFEL	linac, feedback, klystron, electron	1337
	W.H. Hwang, J. Choi, Y.J. Han, J.Y. Huang, H.-G. Kim, S.-C. Kim, I.S. Ko, W.W. Lee PAL, Pohang, Kyungbuk
	In PAL, We are preparing the 3.7 GeV PALXFEL project by upgrading the present 2.5GeV Linac. In present PLS Linac, the specifications of the beam energy spread and rf phase are 0.6%(peak) and 3.5 degrees(peak) respectively. And the output power of klystron is 80 MW at the pulse width of 4 ? and the repetition rate of 10 Hz. In XFEL, the specifications of the beam energy spread and rf phase are 0.03%(rms) and 0.01 degrees(rms) respectively. We developed an analogue and a digital phase measurement and rf phase compensation system for stable beam quality. This paper describes the microwave system for the PALXFEL and the rf phase measurement and phase compensation system.
TUPLS134	Managing the Quality Assurance Documentation of Accelerator Components Using an EDMS	quadrupole, DESY, TTF, PETRA	1819
	L. Hagge, J. Buerger, J.A. Dammann, J. Kreutzkamp, K. Lappe DESY, Hamburg
	Quality assurance (QA) documents are often collected locally on a per-component basis by the manufacturing teams, while project engineers require global evaluations of the QA documents e.g. for production control or during installation and commissioning of the machine. DESY is using an Engineering Data Management System (EDMS) for supporting and unifying the QA documentation of different accelerator components. The EDMS provides dedicated user interfaces which are optimized for the needs of the specific engineering teams which are working on the components (including industrial manufacturers), and at the same time integrates the QA documents into a central database for further overall analysis and applications. The poster introduces the general structure of QA procedures, describes the benefits of using an EDMS for QA documentation and describes examples from different applications at XFEL and PETRA III.
WEXPA01	Latest Developments in Superconducting RF Structures for Beta=1 Particle Acceleration	TESLA, KEK, damping, higher-order-mode	1837
	P. Kneisel Jefferson Lab, Newport News, Virginia
	Superconducting RF technology is since nearly a decade routinely applied to different kinds of accelerating devices: linear accelerators, storage rings, synchrotron light sources and FEL's. With the technology recommendation for the International Linear Collider (ILC) a year ago, new emphasis has been placed on improving the performance of accelerating cavities both in Q-value and in accelerating gradients with the goal to achieve performance levels close to the fundamental limits given by the material parameters of the choice material, niobium. This paper will summarize the challenges to SRF technology and will review the latest developments in superconducting structure design. Additionally, it will give an overview of the newest results and will report on the developments in alternative materials and technologies.
	Transparencies
WEPLS096	Design and Calculation of a Superferric Combined Magnet for XFEL	quadrupole, dipole, DESY, background	2598
	F. Toral, P. Abramian, J.L. Gutierrez, E. Rodriguez, I. Rodriguez, S. Sanz, C. Vazquez CIEMAT, Madrid R. Bandelmann, H. Brueck DESY, Hamburg J. Calero, L. García-Tabarés CEDEX, Madrid J. Lucas Elytt Energy, Madrid
	A planned European X-ray Free Electron Laser so-called XFEL is being developed within the framework of an international collaboration. The design and fabrication of a prototype of a combined magnet is part of the Spanish contribution to this project. This magnet consists of a superferric quadrupole for focusing and two dipoles (horizontal and vertical) for steering, glued around the beam tube. The magnet will be operated in a superfluid helium bath. The aperture is 78 mm. The quadrupole gradient is 35 T/m whereas each dipole field is about 0.04 T. The magnetic saturation is limited to 5% at nominal current, which is quite a challenging specification for such aperture and gradient. As the overall length of the helium vessel is just 300 mm, the calculation of the magnetic field is a pure 3-D problem which has been solved and optimized using two different FEM codes to cross-check the results. This paper also gives some guidelines about the fabrication techniques most suitable for the first prototype, which is now under construction.
THPPA02	High-Gradient Superconducting Radiofrequency Cavities for Particle Acceleration	TESLA, DESY, radio-frequency, acceleration	2752
	L. Lilje DESY, Hamburg
	The development of radiofrequency superconductivity for particle acceleration has reached a level where many projects consider its use. One of the many attractive features of these accelerating structures is to achieve very high accelerating fields efficiently. The technology has been developped to a stage where accelerating gradients of more than 25 MV/m are being implemented in accelerator modules. In single-cell test resonators even higher gradients were already achieved. To operate cavities at these gradients efficiently their frequency needs to be kept stable to reduce the need for an overhead in radiofrequency power. Introducing active elements like piezoelectric actuators allows to achieve these goals.
	Transparencies
THPCH096	Intra Bunch Train Feedback System for the European X-FEL	pick-up, feedback, coupling, controls	3017
	V. Schlott, M. Dehler, B. Keil, R. Kramert, A. Lounine, G. Marinkovic, P. Pollet, M. Roggli, T. Schilcher, P. Spuhler, D.M. Treyer PSI, Villigen
	After joining the preparatory phase of the European X-FEL project, the Paul Scherrer Institut (PSI) agreed in taking over responsibility for electron beam stabilization by developing a fast intra bunch train feedback (IBFB) system, which will be tested in its prototype version at the VUV-FEL facility at DESY. The IBFB will make use of the long bunch trains provided by the superconducting drive accelerators of the VUV- as well as the European X-FEL allowing to damp beam motions in a frequency range of a few kHz up to several hundreds of kHz applying modern control algorithms in a feedback loop. The FPGA-based, digital data processing and the low latency time (preferably < 200 ns) permit the elimination of long range (from bunch train to bunch train) and ultra fast (bunch by bunch) repetitive beam movements by adaptive feed forwards. In this paper, we will introduce the IBFB design concept and report on first test measurements with newly designed stripline beam position monitors for the VUV-FEL.
THPLS132	Physics Requirement of a PLS-XFEL Undulator	undulator, radiation, SASE, FEL	3592
	D.E. Kim, C.W. Chung, I.S. Ko, J.-S. Oh, K.-H. Park PAL, Pohang, Kyungbuk
	Pohang Accelerator Laboratory(PAL)is planning a 0.3nm SASE (Self Amplification of Spontaneous Emission) XFEL based on a 3.7GeV linear accelerator. For short saturation length, application of the SPring8 type in the vacuum undulator is needed. This reflects the experiences from the Spring8 SCSS project. The end structures were designed to be asymmetric along the beam direction to ensure systematic zero 1st field integral. The thickness of the last magnets was adjusted to minimize the transition distance to the fully developed periodic field. This approach is more convenient to control than adjusting the strength of the end magnets. The final design features 4mm minimum pole gap, 15mm period, and peak effective field of 1.09 Tesla. In this article, the physical design of the undulator, the design of the end structure, and the physics requirements of the undulator system will be presented.