IPAC2011 - List of Keywords (undulator)

Paper	Title	Other Keywords	Page
MOYCA01	Status Report on the Commissioning of the Japanese XFEL at SPring-8	laser, acceleration, electron, FEL	21
	H. Tanaka RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	The Japanese XFEL at SPring-8, which was named SACLA (Spring-8 Angstrom Compact free electron LAser), was completed in FY2010. After RF full-power aging for about four months the beam commissioning of SACLA has been started since 21 February 2011. About one month later, in 23 March a design beam energy of 8 GeV was achieved and a spontaneous undulator radiation of 0.8 Angstrom was observed at the beam-line optical hutch by closing XFEL undulator gaps down to 5 mm in full-width. The beam commissioning has proceeded smoothly and since the middle of April we have entered to a tuning phase towards SASE lasing, which is at least one month ahead of schedule. This talk will report the beam commissioning overview of SACLA including SASE XFEL performance, key tuning-processes and critical issues for achieving the lasing.
	Slides MOYCA01 [37.840 MB]

MOOCB02	Commissioning and Performance of the Beam Monitor System for XFEL/SPring-8 “SACLA”	cavity, electron, bunching, FEL	47
	Y. Otake, C. Kondo, H. Maesaka RIKEN Spring-8 Harima, Hyogo, Japan H. Ego, S. Matsubara, T. Matsumoto, T. Sakurai, H. Tomizawa, K. Yanagida JASRI/SPring-8, Hyogo-ken, Japan S.I. Inoue SES, Hyogo-pref., Japan
	The construction of a beam monitor system for XFEL/SPring 8 “SACLA” was completed. The system was developed to realize a spatial resolution of less than 3 um to align a beam orbit for an undulator section with about 100 m long and a temporal resolution to measure bunch lengths from 1 ns to 30 fs to maintain a constant peak beam current conducting stable SASE lasing. The system principally comprises cavity type beam position monitors (BPM), current monitors (CT), screen monitors (SCM) and bunch length measurement instruments, such as an rf deflector and CSR detectors. Commissioning of SACLA started from March 2011, and the monitors performed sufficient roles to tune beams for the lasing. The achieved over-all performances of the system including DAQ are: the BPM have spatial resolution of 300 nm, the bunch length monitors observe bunch lengths from 1ns in an injector with velocity bunching to less than 30 fs after three-stage bunch compressors. The less than a 3 um spatial resolution of the SCM was also confirmed in practical beam operation. By these fulfilled performances, the stable lasing of SACLA will be achieved. This report describes commissioning, performance of the system.
	Slides MOOCB02 [7.516 MB]

MOPC039	Optimization of IH-DTL Resonator for UNDULAC-RF	acceleration, impedance, focusing, ion	160
	S.M. Polozov, A.S. Plastun, P.R. Safikanov MEPhI, Moscow, Russia
	The linear undulator accelerator (UNDULAC) was proposed early for ribbon ion beam acceleration. UNDULAC can be realized using two non-synchronous spatial harmonics. One of them must be RF field harmonic and the second can be RF (UNDULAC-RF) or electrostatic (UNDULAC-E). The acceleration mechanism in UNDULAC is similar as inverse free electron laser (IFEL). The beam dynamics in both types of UNDULAC was studied early and the design of UNDUAC-RF resonator was started in . Design of the 150 MHz IH-DTL for UNDULAC-RF will present. The optimization of the longitudinal field distributions will do. The most effective construction will show. Transverse electric field distributions within drift tube will optimize by blending support stems and drift tubes. E.S. Masunov, Sov. Phys. – Tech. Phys. 35(8), 962-965, 1990. ** S. M. Polozov, P. R. Safikanov, Proc. IPAC’10, Kyoto, Japan, p. 3762 (2010).

MOPO016	Commissioning Tune Feedback in the Taiwan Light Source	feedback, insertion, insertion-device, controls	517
	C.H. Kuo, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.-Y. Liao, C.Y. Wu NSRRC, Hsinchu, Taiwan
	The tune control is important parameter in the insertion devices operation. There are many difference type insertion devices are disturbed in the storage ring of TLS. The traditional feed-forward control to correct orbit change and tune shift that isn’t enough when difference type insertion devices are operated with various condition. The tune feedback is used to solve the tune change problem. The stable tune measurement is necessary in the stable storage ring. There are various excited bunch train methods to get stable tune that will be also discussed in this report.

TUZA01	Commissioning and Initial Operation of FERMI@Elettra	FEL, electron, laser, photon	918
	S. Di Mitri, E. Allaria, R. Appio, L. Badano, S. Bassanese, F. Bencivenga, A.O. Borga, M. Bossi, E. Busetto, C. Callegari, F. Capotondi, K. Casarin, D. Castronovo, P. Cinquegrana, D. Cocco, M. Cornacchia, P. Craievich, R. Cucini, I. Cudin, G. D'Auria, M.B. Danailov, R. De Monte, P. Delgiusto, A.A. Demidovich, B. Diviacco, A. Fabris, R. Fabris, W.M. Fawley, M. Ferianis, S. Ferry, V. Feyer, L. Fröhlich, P. Furlan Radivo, G. Gaio, F. Gelmetti, L. Giannessi, R. Gobessi, R. Ivanov, E. Karantzoulis, M. Kiskinova, M. Lonza, A.A. Lutman, C. Masciovecchio, R.H. Menk, M.M. Milloch, M.M. Musardo, I. Nikolov, S. Noe, F. Parmigiani, L. Pavlovič, E. Pedersoli, G. Penco, M. Petronio, M. Predonzani, E. Principi, E. Quai, G. Quondam, F. Rossi, L. Rumiz, C. Scafuri, C. Serpico, P. Sigalotti, C. Spezzani, M. Svandrlik, C. Svetina, M. Trovò, A. Vascotto, M. Veronese, R. Visintini, D. Wang, M. Zaccaria, D. Zangrando ELETTRA, Basovizza, Italy M. Alagia, A. Kivimaki, M. Zangrando, M. de Simone IOM-CNR, Trieste, Italy L. Avaldi, P. Bolognesi, M. Coreno, P. O’Keeffe CNR - IMIP, Trieste, Italy M. Dal Forno DIEIT, Trieste, Italy G. De Ninno, S. Spampinati University of Nova Gorica, Nova Gorica, Slovenia M. Devetta, T. Mazza, P. Piseri Università degli Studi di Milano, Milano, Italy E. Ferrari Università degli Studi di Trieste, Trieste, Italy S. Stranges Università di Roma "La Sapienza", Roma, Italy
	Funding: Work was supported in part by the Italian Ministry of University and Research under grants FIRB-RBAP045JF2 and FIRB-RBAP06AWK3. This article describes the design goals of FERMI@Elettra, reports on the goals achieved so far and shows how the facility development has been driven by the new research frontier of ultra-fast, extreme ultra-violet and soft X-ray science. The commissioning phases and first experience with user pilot experiments are presented and discussed.
	Slides TUZA01 [13.401 MB]

TUZA02	sFLASH - Present Status and Commissioning Results	electron, laser, FEL, radiation	923
	V. Miltchev, S. Ackermann, A. Azima, J. Bödewadt, F. Curbis, M. Drescher, E. Hass, Th. Maltezopoulos, M. Mittenzwey, J. Rönsch-Schulenburg, J. Roßbach, R. Tarkeshian Uni HH, Hamburg, Germany H. Delsim-Hashemi, K. Honkavaara, T. Laarmann, H. Schlarb, S. Schreiber, M. Tischer DESY, Hamburg, Germany R. Ischebeck PSI, Villigen, Switzerland S. Khan DELTA, Dortmund, Germany
	The free-electron laser in Hamburg (FLASH) was previously being operated in the self-amplified spontaneous emission (SASE) mode, producing photons in the XUV wavelength range. Due to the start-up from noise the SASE-radiation consists of a number of uncorrelated modes, which results in a reduced coherence. One option to simultaneously improve both the coherence and the synchronisation between the FEL-pulse and an external laser is to operate FLASH as an amplifier of a seed produced using high harmonics generation (HHG). An experimental set-up - sFLASH, has been installed to test this concept for the wavelengths below 40 nm. The sFLASH installation took place during the planed FLASH shutdown in the winter of 2009/2010. The technical commissioning, which began in the spring of 2010, has been followed by seeded-FEL commissioning, FEL-characterisation and pilot experiments. In this contribution the present status and the sFLASH commissioning results will be discussed.
	Slides TUZA02 [4.125 MB]

TUODB03	Innovative Design of the Fast Switching Power Supplies for the SOLEIL EMPHU Insertion and its Fast Correctors	power-supply, controls, simulation, permanent-magnet	982
	F. Bouvet, D. Aballea, R. Ben El Fekih, S. Bobault, M. Bol, Y. Bouanani, Y. Dietrich, A. Hardy, F. Marteau SOLEIL, Gif-sur-Yvette, France
	A new electromagnetic/permanent magnets helical undulator has been designed and is under commissioning at SOLEIL. For a fast switching of the photon polarization, it requires a power supply able to switch between +/350 A within 50 ms, without any current overshoot and with a very good current resolution over the full scale (50 ppm). The in-house design is based on two full switching bridges with interleaved commands. Combined with a regulation scheme using sophisticated algorithms, such a design enables to reach a high control bandwidth, permitting fast transitions. Such a fast and accurate system needs well performing digital control electronics. We chose the digital control cards developed at Paul Scherrer Institute (Villigen CH) for the SLS (Swiss Light Source). The components, measurements, interlocks, control interfaces, and electronic cards were developed and assembled together at SOLEIL. This paper will present the main lines of this development and the performances achieved during the EMPHU insertion commissioning. The design of the fast power supplies (±20 A) needed for corrector magnets of this insertion will also be presented.
	Slides TUODB03 [3.017 MB]

TUPC006	Production of Highly Polarized Positron Beams*	polarization, positron, photon, target	997
	A. Ushakov, O.S. Adeyemi, V.S. Kovalenko, L.I. Malysheva, G.A. Moortgat-Pick University of Hamburg, Hamburg, Germany A.F. Hartin DESY, Hamburg, Germany S. Riemann, A. Schälicke, F. Staufenbiel DESY Zeuthen, Zeuthen, Germany
	Funding: This work is supported by the German Federal Ministry of Education and Research, Joint Research Project R&D Accelerator "Spin Management", contract number 05H10GUE Using of polarized electron and positron beams significantly increases the physics potential of future linear colliders. The generation of an intense and highly polarized positron beam is a challenge. The undulator-based positron source located at the end of electron linac is the baseline source for the International Linear Collider. In case of a 250 GeV drive beam energy, an helical undulator with K = 0.92, an undulator period of 11.5 mm and a titanium alloy target of 0.4 radiation length thickness, the average polarization of the generated positrons is relatively low (about 22 percent). In this contribution, the possibilities of increasing the positron polarization have been considered by adjusting the undulator field and selecting those photons and positrons that yield a highly polarized beam. The detailed simulations have been performed with our developed Geant4-based application PPS-Sim. http://pps-sim.desy.de

TUPC069	Bunch Length Measurements from the Incoherent Synchrotron Radiation Fluctuation at SOLEIL	radiation, optics, electron, photon	1159
	M.-A. Tordeux, F. Dohou, M. Labat, O. Marcouillé SOLEIL, Gif-sur-Yvette, France
	Bunch length measurements can be made by analysing the pulse to pulse intensity fluctuation of the incoherent synchrotron radiation as it has been reported elsewhere. Such a method has been tested at SOLEIL for picosecond bunch durations, at several wavelengths and bandwidths in the visible range, using an avalanche photodiode. Thanks to the low-alpha optics the lengths of 10 μA bunches as short as 3 ps have been measured in good agreement with the streak camera results. We first used the radiation from a bending magnet, and then from a HU640 undulator that enhances the photon flux. Moreover, taking advantage of using the radiation from an undulator, we show that the method can still be used when the number of spikes emitted by the electron bunch is reduced to a few hundreds. This could be of interest for bunch length measurements of X-ray SASE FELs. Furthermore, we intend to use a single crystal diamond detector in order to perform these measurements in the X-ray range. F. Sannibale et al., "Absolute bunch length measurements by incoherent radiation fluctuation analysis", PRST AB 12, 032801 (2009).

TUPC091	Operational Results of the Diamond-based Halo Monitor during Commissioning of SPring-8 XFEL (SACLA)	electron, laser, wakefield, scattering	1218
	H. Aoyagi JASRI/SPring-8, Hyogo-ken, Japan Y. Asano, H. Kitamura, T. Tanaka RIKEN/SPring-8, Hyogo, Japan
	Funding: This work is partly supported by Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (c) 21604017. Measurement of electron beam halo is very important issue for X-ray free electron laser and synchrotron radiation facilities, because the beam halo may cause radiation damage of undulator magnets. Furthermore, it may cause degradation in quality of electron beam, and radio activation of beam ducts and components. In order to prevent these situations, a diamond-based halo monitor (HM) has been developed for the SPring-8 Angstrom Compact free electron LAser (SACLA). We have achieved excellent detection limit of 0.3 fC/pulse for single-shot measurement, which corresponds to the ratio of 10^-6 to the beam core. The commissioning of the HM, which was installed at the upstream of 90m undulator, has been carried out, and it has been figured out that the intensity of the beam halo can be measured very nicely since secondary electrons and bremsstrahlung that are emitted in the accelerator components have not been observed. We also describe systematic profile measurements of the beam halo and operational results of the HM during the commissioning of SACLA.

TUPC160	Recent Developments of Diagnostics at Diamond	photon, feedback, synchrotron, diagnostics	1407
	G. Rehm, C. Bloomer, A.F.D. Morgan, C.A. Thomas Diamond, Oxfordshire, United Kingdom
	This contribution summarizes some recent development of diagnostics system to improve the operation of Diamond Light Source. Firstly, we are advancing the integration of photon beam diagnostics with the orbit feedback system. Measurements have shown the correlation between recorded electron and photon beam motion on the short timescales (ms-minutes) and the potential for improvement on long timescales (minutes-days). Secondly, with the addition of more elliptically polarized undulators at Diamond, measurement of their photon beam position require a solution that reliably operates with the changing photon beam profiles emitted by these devices. To this end, we have developed an X-ray beam position monitor that analyzes the backscatter from an aperture in the front end. Thirdly, as operation in low-alpha mode with few ps bunch lengths receives increasing interest from users, we have been evaluating various techniques for the measurement of these short bunch lengths that could serve as alternatives to streak camera measurements.

TUPO004	Generation of Attosecond Soft X-ray Pulses in a Longitudinal Space Charge Amplifier	electron, space-charge, laser, radiation	1449
	M. Dohlus, E. Schneidmiller, M.V. Yurkov DESY, Hamburg, Germany
	A longitudinal space charge amplifier (LSCA), operating in soft x-ray regime, was recently proposed. Such an amplifier consists of a few amplification cascades (focusing channel and chicane) and a short radiator undulator in the end. Broadband nature of LSCA supports generation of few-cycle pulses as well as wavelength compression. In this paper we consider an application of these properties of LSCA for generation of attosecond x-ray pulses. It is shown that a compact and cheap addition to the soft x-ray free electron laser facility FLASH would allow to generate 60 attosecond (FWHM) long x-ray pulses with the peak power at 100 MW level and a contrast above 98%.

TUPO005	Design Optimization for a Non-Planar Undulator for the JETI-Laser Wakefield Accelerator in Jena	electron, laser, radiation, wakefield	1452
	V. Afonso Rodriguez, T. Baumbach, A. Bernhard, G. Fuchert, A. Keilmann, P. Peiffer, C. Widmann KIT, Karlsruhe, Germany M. Kaluza, M. Nicolai IOQ, Jena, Germany R. Rossmanith Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
	In a laser wakefield accelerator (LWFA), excited by a femtosecond laser pulse electrons are accelerated to several 100 MeV within a few centimeters. The energy spread of the electron beam is relatively large and varies from shot to shot. In order to obtain monochromatic photons in an undulator despite the energy spread, the following idea was proposed. Two bending magnets and a drift space in between produces dispersion so that particles with different energies have different transverse positions. The beam enters a non-planar undulator, e.g. cylindrical pole geometry, where the K-value also varies with transverse position. If the two variations in the transverse direction (particle energy and K-value) compensate each other the generated light is more monochromatic than with a conventional planar undulator. In this paper such a modified undulator design optimized for the JETI-LWFA in Jena is presented. An experiment to test this concept is in preparation.

TUPO006	Design of a Dispersive Beam Transport Line for the JETI Laser Wakefield Accelerators	radiation, electron, dipole, quadrupole	1455
	C. Widmann, V. Afonso Rodriguez, T. Baumbach, A. Bernhard, P. Peiffer KIT, Karlsruhe, Germany M. Kaluza, M. Nicolai IOQ, Jena, Germany R. Rossmanith Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
	Laser wakeﬁeld accelerators (LWFA) emit electrons with energies of a few 100 MeV at very short bunch lengths while having a compact design. However, electron bunches from LWFA show a larger energy spread than those of conventional accelerators. This is a challenge when using these bunches e.g. to generate radiation in an undulator. A possible strategy to cope with that is to spectrally disperse the bunch and match the resulting spatial distribution with a spatially varying undulator ﬁeld amplitude. For realizing the dispersion a pair of dipole magnets is used. The electrons leaving this dipole chicane have to meet certain requirements imposed by the undulator: In the deﬂection plane the beam has to be collimated and its energy distribution must match the undulator ﬁeld. In the other transversal plane the beam has to be focussed on the center of the undulator keeping the value of the beta function small. To include this in the compact design of the setup, a combination of specially designed quadrupole and sextupole magnets is employed. In this contribution the design of the setup and the results of the particle tracking through this chicane are presented.

TUPO017	Peculiarities of the Excitation of an Optical Resonator by an Electron Beam	electron, radiation, damping, storage-ring	1479
	E.G. Bessonov, M.V. Gorbunkov, A.L. Osipov LPI, Moscow, Russia A.A. Mikhailichenko CLASSE, Ithaca, New York, USA
	The peculiarities of the optical resonator excitation by electrons in a FEL based on the Self-Stimulated Undulator Radiation at main and collateral synchronicity conditions are discussed. E.G.Bessonov et al., Self-Stimulated Undulator Radiation and its Possible Applications, http://arxiv.org/ftp/arxiv/papers/10⁰⁹/1009.3724.pdf

TUPO018	Self-stimulated Undulator Klystron	FEL, electron, kicker, storage-ring	1482
	E.G. Bessonov, A.L. Osipov LPI, Moscow, Russia A.A. Mikhailichenko CLASSE, Ithaca, New York, USA
	The Self Stimulated Undulator Klystron (SSUK) and its possible applications in the Particle Accelerator Physics, incoherent Self-Stimulated Undulator Radiation Sources (SSUR) and Free-Electron Lasers are discussed. E.G.Bessonov et al., Self-Stimulated Undulator Radiation and its Possible Applications: http://arxiv.org/ftp/arxiv/papers/10⁰⁹/1009.3724.pdf

TUPS012	The Present Status of Vacuum System of XFEL in SPring-8	vacuum, shielding, electron, laser	1542
	T. Bizen RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan T. Hasegawa RIKEN/SPring-8, Hyogo, Japan
	The vacuum component assembly and installation were completed by February in 2011. The total length of the vacuum system is about 630 m. A 455 sputter ion pumps and a 10⁸ NEG cartridge pumps generate vacuum. The average pressures are on the order of ·10^-7 Pa or less. The flange developed for C-band waveguide shows high reliability of vacuum seal.

WEXA01	Challenges of 4th Generation Light Sources	FEL, electron, emittance, photon	3798
	C. Pellegrini SLAC, Menlo Park, California, USA C. Pellegrini UCLA, Los Angeles, California, USA
	In the last few years Free Electron Lasers (FELs) have emerged as exceptionally exciting tools for new science. The results from FLASH (Hamburg) on biological imaging, LCLS (Stanford) which generated the first hard X-ray lasing and the projects proposed or in costruction around the world are rapidly moving the scientific community to the so called “fast science” which demands ultrashort pulses, fs synchronization, high brightness, high coherence X-rays. The basic SASE FEL process used so far converts energy jitter into jitter of the centralwavelength. Processes based on seeding and HGHG seem to offer a number of advantages in terms of bandwidth, coherence, stability and undulator length. This talk will present an overview of the 4th generation light sources, discussing the main challenges afforded in the construction of the operating facilities and considering the trends for the development of future facilities.
	Slides WEXA01 [10.640 MB]

WEOBB02	Bunch Length Diagnostic with Sub-femtosecond Resolution for High Brightness Electron Beams	laser, electron, simulation, cavity	1967
	G. Andonian, E. Hemsing, P. Musumeci, J.B. Rosenzweig UCLA, Los Angeles, California, USA A.Y. Murokh RadiaBeam, Santa Monica, USA D. Xiang SLAC, Menlo Park, California, USA
	Next generation light sources require electron beams with high peak currents, typically achieved by compression techniques. The temporal diagnosis of these ultra-short beams demands enhanced resolution. We describe a scheme to achieve a temporal resolution on the order of sub-femtoseconds. The scheme is based on encoding the longitudinal profile of the beam on a transverse angular modulation, based on an interaction between the electron beam and a high-power laser in an undulator. This imposes a fast-sweep of the beam, on the order of sub-femtoseconds. A subsequent sweep in the orthogonal dimension by an rf deflecting cavity, imposes a "slow-sweep" on the order of sub-picoseconds. In this paper, we demonstrate applicability of this diagnostic scheme at the BNL ATF and specify the techniques required for practical applicability.
	Slides WEOBB02 [1.120 MB]

WEPC008	Optics for the Beam Switchyard at the European XFEL	kicker, septum, quadrupole, extraction	2016
	N. Golubeva, V. Balandin, W. Decking DESY, Hamburg, Germany
	The European XFEL is planed as a multi-user facility with the possibility to distribute electron bunches of one beam pulse to different beamlines. The initial stage foresees two electron beamlines each serving its own set of undulators. The later addition of a third beamline is also considered in the design of the distribution system. In addition, the integration of the transport line to the beam abortion dump allows a flexible selection of the bunch repetition pattern for each beamline. The beam extraction, both in undulator beamlines and in the beamline to the dump, will be realized with fast kickers and a Lambertson septum. In this paper we describe the magnet lattice of the deflection arcs with simultaneous horizontal and vertical dispersions and the beam optics of the beam switchyard.

WEPC050	New Optics for the SOLEIL Storage Ring	optics, injection, coupling, vacuum	2124
	P. Brunelle, F. Briquez, A. Loulergue, O. Marcouillé, A. Nadji, L.S. Nadolski, M.-A. Tordeux, J.F. Zhang SOLEIL, Gif-sur-Yvette, France
	SOLEIL, the French 2.75GeV synchrotron light source is delivering photons to 24 beam lines and is presently equipped with 22 insertion devices (ID) including a high field and small gap in-vacuum wiggler. This paper presents the continuous work performed to reduce the strong non linear effects of several IDs. On one side, the ID defaults have been precisely identified using on-beam measurements, and magnetic correction developments are going on, especially for the in-vacuum wiggler and for the 10m long HU640 undulator. On the other side, a new optics has been optimised in terms of beta-functions (at the ID location) and non linear dynamics in order to improve the injection efficiency and the beam lifetime in the presence of IDs. The modified optics has been used daily in operation since November 2010 and ensures a beam lifetime greater than 10h for a 400mA stored beam with the users ID configuration. In parallel, an extensive experimental optimization has been performed to prepare the operation with an additional quadrupole triplet that provides double low vertical beta functions in one long straight section that will accommodate two canted in-vacuum insertion devices. O. Marcouillé et al., IPAC10, p. 3102 (2010). ** A. Loulergue et al., IPAC10, p. 2496 (2010).

WEPC072	Insertion Devices and Beam Dynamics in the PLS-II Storage Ring	wiggler, betatron, insertion, insertion-device	2187
	S. Chunjarean, S. Shin PAL, Pohang, Kyungbuk, Republic of Korea
	Effects of insertion devices like a superconducting multipole wiggler or an in-vacuum undulator on the beam dynamics of tghe upgraded Pohang Light Source (PLS-II) storage ring have been investigated. The narrow gap related to a short period length of the in-vacuum undulator or a transverse magnetic field roll off can impact the dynamic aperture or Touschek lifetime or injection efficiency. A three dimensional magnetic field model has been developed based on numerical data consisting of several coefficients in the Taylor expansion to accurately represent the actual field. In this paper, the magnetic field model has been produced with the differential algebraic code COSY INFINITY to formulate the Taylor transfer map for the wiggler and undulator. Frequency map analysis (FMA) and full 6D tracking has been performed to investigate resonances which may affect the particle stability and causing a reduction in injection efficiency.

WEPC137	Undulator Radiation Simulation by QUINDI	radiation, electron, simulation, polarization	2316
	D. Schiller, E. Hemsing, J.B. Rosenzweig UCLA, Los Angeles, California, USA
	QUINDI, a code developed to simulate coherent emission from bending systems, has been upgraded to include undulators as a beamline element. This approach allows us to better model the radiation produced by a relativistic electron bunch propagating through such a device.

WEPC163	A New Embedded Radiation Monitor System for Dosimetry at the European XFEL	radiation, neutron, controls, linac	2364
	F. Schmidt-Föhre, D. Nölle, R. Susen, K. Wittenburg DESY, Hamburg, Germany L. Fröhlich ELETTRA, Basovizza, Italy
	The upcoming European XFEL will be built at a length of approx. 3.4 km between the campus of the Deutsches Elektronen-Synchrotron DESY at Hamburg and Schenefeld at Schleswig-Holstein for commissioning in 2015. The XFEL utilizes various electronic systems for machine control, diagnostics and safety. To achieve a cheap and compact accelerator construction, the beam pipe and its nearby electronic supply systems are located inside the same tunnel, charged by an evident amount of radiation in certain sections of the XFEL. To insure the lifecycle and function of electronics and magnetic structures like undulators in these XFEL radiation fields, all electronic systems located inside the tunnel will be sufficiently shielded according to pre-estimated radiation levels. In addition, these electronics and the undulator parts will be monitored for the impact of Gamma- and Neutron-radiation by a new versatile and compact radiation monitor system. It measures the accumulated dose in the electronic cabinets along the XFEL to ensure an exchange of radiated parts before significant radiation damage occurs. First prototype measurements at different radiation sources will be presented.

WEPC164	First Operation of a Fiber Beam Loss Monitor at the SACLA FEL	beam-losses, vacuum, electron, radiation	2367
	X.-M. Maréchal, T. Itoga JASRI/SPring-8, Sayo-gun, Japan Y. Asano RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	A fiber-based Cerenkov beam loss monitor (CBLM) has been developed as a quick and long-range detection tool for radiation safety at the X-ray FEL SACLA (SPring-8 angstrom compact free electron laser) to minimize electron beam losses. Based on tests carried out at the 250 MeV SPring-8 Compact SASE Source facility, large core (400 μm), long (>120 m) multimode fibers were selected and installed in the undulator section of SACLA. We report on the first few months of operation of the CBLM. During the commissioning of the X-FEL, the CBLM has performed effectively, with a detection limit below 10 pC per pulse across the 110 meters of the in-vacuum undulators, and with a position accuracy of less than 2 m. Experimental results are presented along with detailed numerical studies including the geometry of in-vacuum insertion devices, and discussed.

WEPC169	BPM System Interlock for Machine Protection at SOLEIL	photon, vacuum, power-supply, electron	2379
	J.-C. Denard, C. Herbeaux, M. Labat, V. Leroux, A. Loulergue, J.L. Marlats SOLEIL, Gif-sur-Yvette, France
	SOLEIL, a third generation light source, has its Beam Position Monitors (BPM) processed by the LIBERA electronics built by Instrumentation Technologies. This electronics initiated and specified by SOLEIL features a fast hardware interlock output for machine protection. Although interlocks are available in both horizontal and vertical planes, it was initially thought that only the vertical interlocks would be useful. Actually, the high photon beam power densities (up to 1kW/mm2) generated by the in-vacuum undulators could damage vacuum chamber elements in case of corrector power supply failures in horizontal or vertical plane. Crotch absorbers, XBPMs and their upstream absorbers were designed on the basis that they will be protected with interlock thresholds not tighter than ±1mm. This approach was also applied for specifying the apertures of the XBPMs and of their upstream absorbers. More recently tracking simulation has shown that the crotch absorber apertures downstream the new canted undulators needed special attention.

THPC009	Performance and Upgrade of the ESRF Light Source	emittance, cavity, storage-ring, vacuum	2924
	J.-L. Revol, J.C. Biasci, J-F. B. Bouteille, J. Chavanne, F. Ewald, L. Farvacque, A. Franchi, G. Gautier, L. Goirand, M. Hahn, L. Hardy, J. Jacob, J.M. Koch, M.L. Langlois, G. Lebec, J.M. Mercier, T.P. Perron, E. Plouviez, K.B. Scheidt, V. Serrière ESRF, Grenoble, France
	The European Synchrotron Radiation Facility (ESRF) is now fully engaged in a large Upgrade Programme of its infrastructure, beamlines and X ray source. In this context, a first set of 10 insertion device straight sections are being lengthened from five to six metres; a number of them will be operated with canted undulators. The insertion devices are themselves subject to an ambitious development programme to fulfil the scientific requirements. The Radio Frequency system upgrade has started with the replacement of the booster klystron-based transmitter by high power solid state amplifiers, and the development of HOM damped cavities operating at room temperature. A completely new DC-AC orbit stabilization system using 224 BPMs and 96 orbit steerers is currently being commissioned. The upgrade is conducted while keeping, and even improving, routine performance for the user service. In particular the recent installation of new skew quadrupole power supplies allows routine operation with ultra low vertical emittance. This paper reports on the present operation performance of the source, highlighting recent developments and those still to come.

THPC012	Mitigating the Pertubations Caused by U 180 at the Metrology Light Source	dipole, quadrupole, optics, focusing	2930
	P.O. Schmid, D.B. Engel, J. Feikes, M. Ries, G. Wüstefeld HZB, Berlin, Germany
	The Metrology Light Source is equipped with an electromagnetic undulator with a period length of 180 mm. User requests demand operation of this undulator in a wide energy range from 100 MeV through 629 MeV for user and dedicated low alpha modes. Mitigating the pertubations caused by the undulator to an acceptable level for all user requests, requires each quadrupole in the lattice to be powered individually. To what extend this recently implemented capability allows the restoration of the main properties of the machine optics for various settings of the undulator is presented in this document.

THPC015	A Dedicated THz Beamline at DELTA	laser, electron, radiation, simulation	2939
	M. Höner, M. Bakr, H. Huck, S. Khan, R. Molo, A. Nowaczyk, A. Schick, P. Ungelenk, M. Zeinalzadeh DELTA, Dortmund, Germany
	Funding: Work supported by DFG, BMBF, and by the Federal State NRW As a consequence of the new radiation source for ultrashort VUV pulses at DELTA, which is based on the interaction of electrons with fs laser pulses, coherent THz radiation is emitted. Simulations of the laser-electron interaction, particle dynamics and radiation spectrum, as well as the optical and mechanical design of a dedicated THz beamline are presented. First experimental results including laser-electron overlap diagnostics and characterization of the THz radiation are discussed.

THPC016	Ultrashort VUV and THz Pulse Generation at the DELTA Storage Ring	laser, electron, radiation, klystron	2942
	A. Schick, M. Bakr, H. Huck, M. Höner, S. Khan, R. Molo, A. Nowaczyk, P. Ungelenk, M. Zeinalzadeh DELTA, Dortmund, Germany
	Funding: Supported by DFG, BMBF, and the Federal State NRW The optical klystron (two undulators, separated by a dispersive section) at DELTA, formerly operated as storage-ring FEL, is seeded with ultrashort pulses from a Ti:Sapphire laser. The thus induced energy modulation of an electron bunch in the first undulator is converted to a density modulation within the dispersive chicane. In the second undulator, the micro-bunched electrons emit ultrashort pulses coherently at harmonics of the fundamental laser wavelength. Additionally, coherent ultrashort THz pulses are generated several meters downstream of the optical klystron by the laser-induced gap in the electron bunch. First results are presented.

THPC017	Temporal and Spatial Alignment of Electron Bunches and Ultrashort Laser Pulses for the CHG Experiment at DELTA	laser, electron, controls, synchrotron	2945
	M. Zeinalzadeh, M. Bakr, H. Huck, M. Höner, S. Khan, R. Molo, A. Nowaczyk, A. Schick, P. Ungelenk DELTA, Dortmund, Germany
	Funding: Supported by DFG, BMBF, and the Federal State NRW The generation of ultrashort VUV pulses by CHG (Coherent Harmonic Generation) requires achieving and maintaining the longitudinal and transversal overlap of femtosecond laser pulses and electron bunches. We present the techniques and the experimental setup applied at the DELTA storage ring. For the longitudinal analysis, both a streak camera and a fast photo diode are used. Transversely, two CCD cameras acquire images of laser and synchrotron light at different positions inside of the undulator. A feedback system utilizes the intensity of a THz signal generated several meters downstream of the undulator to optimize and maintain the overlap.

THPC020	PETRA III Upgrade	sextupole, optics, focusing, single-bunch	2948
	K. Balewski, M. Bieler, J. Keil, A. Kling, G.K. Sahoo, R. Wanzenberg DESY, Hamburg, Germany
	PETRA III, the new third generation light source at DESY, has been running as a user facility since middle of 2010. All 14 undulator beam lines have been commissioned and up to 12 of them are currently in operation. However, already during the planning phase of PETRA III it turned out that the number of beamlines will not be sufficient to fulfill the request for beam time. The pressure to add more beamlines to PETRA III even increased after the decision to shut down DORIS III at the end of 2012. To increase the number of experimental stations two additional halls will be built each housing 5 additional beam lines and about 100 m of the accelerator close to each of the new buildings will be completely remodeled to install additional undulators. The upgrade has been formally approved and at present should be accomplished during a 6 month shut down in 2013. In this paper the layout of the upgraded accelerator will be shown. The impact of the upgrade on machine performance has been studied both theoretically and experimentally and the results of these studies will be presented.

THPC029	Ultra-low Emittance Light Source Storage Ring Consisting of 5-Bend Achromat Cells with Four Long Straight Sections	lattice, emittance, storage-ring, wiggler	2972
	K. Tsumaki JASRI/SPring-8, Hyogo-ken, Japan
	The 6 GeV ultimate storage ring (USR) consisting of ten bend achromat cells has been proposed* and applied it to the SPring-8 Storage ring*. It has the same circumference as the SPring-8 storage ring, but does not have four long straight sections, where the SPring-8 storage ring does. The cell length is twice of that of the SPring-8 storage ring and the number of cell is half of the SPring-8. The photon beam line positions would deviate from those of the existing one. To avoid these problems, we designed a storage ring that has four long straight sections and same cell number. The cell is changed from ten bend achromat to five bend achromat and the cell length is shortened to 30 m which is the same length of the SPring-8 storage ring unit cell. The total ring consists of 44 five bend achromat cells and four long straight section cells. The emittance is 10⁴ pm and it will reduce to less than 50 pm by radiation damping of wigglers and undulators. The brightness is expected to be more than 10²2 phs/s/mm²/mrad² in 0.1%BW with 200 mA beam current. K. Tsumaki, N. Kumagai, NIM A 565 (2006) 394. ** K. Tsumaki, N. Kumagai, Proc. of EPAC06, THPLS035, p. 3362 (2006).

THPC040	Expected Performance Characteristic of Accelerator-based THz Source at Tohoku University	radiation, electron, focusing, gun	2990
	H. Hama, F. Hinode, S. Kashiwagi, M. Kawai, X. Li, T. Muto, K. Nanbu, Y. Tanaka Tohoku University, School of Science, Sendai, Japan N.Y. Huang NTHU, Hsinchu, Taiwan
	Funding: This work is supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research (S), Contract #20226003. Sources of coherent synchrotron radiation at THz wavelength region have been constructed at Tohoku University. Bunch train of extremely shorter electron pulse less than 100 fs will be provided by an injector linac employing thermionic rf gun, where the bunch compression will be performed by means of velocity bunching in an accelerator structure. Radiation source under development are a Halbach type planar undulator and an accumulator isochronous ring. The undulator employs large gap and long period length configuration, so that the resonant frequency of 1 THz is achieved when a lower beam energy of ~ 20 MeV. Since spectrum of coherent synchrotron radiation (CSR) is strongly depending on longitudinal bunch form factor, we have calculated CSR spectra for various conditions of the beam to evaluate the performance of the THz source. Numerical simulation with multi-particle system has been carried out to understand the radiation power and angular distribution as well. The beam transport in the undulator is crucial for quality of the radiation because the beam energy is very much low relative to strong focusing power. Characteristics of THz CSR from the undulator will be discussed.

THPC042	Status and Development of the SAGA Light Source	storage-ring, laser, controls, linac	2996
	T. Kaneyasu, Y. Iwasaki, S. Koda, Y. Takabayashi SAGA, Tosu, Japan
	The SAGA Light Source (SAGA-LS) is a synchrotron radiation facility consisting of a 255 MeV injector linac and a 1.4 GeV storage ring, and has been stably providing synchrotron light since 2006. The annual failure time is less than 1% of the user time in the recent two years. Three insertion devices are installed in the storage ring: an APPLE-II undulator, a planar type undulator (Saga Univ.) and a 4 T superconducting wiggler (SCW). The SCW contains a hybrid three-pole magnet; the main pole of the magnet is surrounded by superconducting coils while side poles are normal conducting magnets. The main pole of the SCW is cooled by a GM cryocooler, which allows the SCW be operated without liquid helium. Since the installation in March 2010, the SCW has been operated stably. To control the ID parameters during the user time, a feed-forward correction system which minimizes the ID effects on the emittance coupling was developed. The laser Compton Gamma-rays were generated by using a CO2 laser and were used for beam energy measurement. In addition, research works on the beam lifetime and interaction between electron beam and crystal, and development of a multipole magnet are in progress.

THPC044	Operation and Performance Upgrade of the Soleil Storage Ring	vacuum, storage-ring, photon, feedback	3002
	A. Nadji, P. Brunelle, M.-E. Couprie, J.-C. Denard, J.-M. Filhol, J.-F. Lamarre, P. Lebasque, A. Loulergue, P. Marchand, L.S. Nadolski, R. Nagaoka, M.-A. Tordeux SOLEIL, Gif-sur-Yvette, France
	SOLEIL delivers photons to 24 beamlines. Up to 22 very diverse insertion devices (IDs) are now installed on the storage ring, and 4 more will come by summer 2011, including a Cryogenic undulator and an electromagnetic/permanent magnet helical undulator, both designed and built at SOLEIL. Work is continuing on beam dynamics and magnetic corrections to reduce the nonlinear effects of all these IDs. A new optics incorporating an additional quadrupole triplet in one long straight section has been successfully tested and will be put in operation by fall 2011. A new coupling correction will also be implemented to maintain the ratio of the vertical to the horizontal emittances at 1% for any IDs configuration. The electron beam orbit stability has been significantly improved reaching a residual noise of 300 nm RMS. Photon LIBERA modules of X-BPM located on the bends, will be integrated soon in the orbit feedback loops. 4905 hours have been delivered in 2010 to the beamlines with an availability of 96.3%. The user operation with the maximum current of 500 mA is foreseen to start by fall 2011, after the completion of the radiation safety tests of the beamlines.

THPC055	Front Ends at ALBA	vacuum, photon, radiation, synchrotron	3017
	J. Marcos, J. Campmany, D. Einfeld, J. Pasquaud CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	ALBA is a 3GeV 3rd generation synchrotron radiation source built nearby Barcelona currently under commissioning phase. This paper describes the design and installation of the set of 10 Front Ends that have been manufactured and assembled for day-one operation of the facility. This initial set includes 8 Front Ends devoted to transmit the photons generated by both Insertion Device or Bending Magnet sources to experimental Beamlines, and 2 additional Front Ends for electron beam-diagnostics purposes. The design of each individual Front End has been adapted in order to meet the aperture and power load requirements posed by both the characteristics of the photon sources and the needs of the Beamline users. At the same time, an effort has been made in order to keep a suitable degree of standardization among the components of different Front Ends. With this aim a modular design approach has been adopted. The general layout of the Front Ends as well as the design and function of their main components is described. Finally, a brief summary of their performance during the commissioning period is presented.

THPC079	Echo-enabled Harmonic Generation at DELTA	laser, electron, bunching, storage-ring	3074
	R. Molo, M. Bakr, H. Huck, M. Höner, S. Khan, A. Nowaczyk, A. Schick, P. Ungelenk, M. Zeinalzadeh DELTA, Dortmund, Germany
	Funding: Supported by DFG, BMBF, and the Federal State NRW We present conceptual studies of the realization of the echo-enabled harmonic generation (EEHG) technique proposed by G. Stupakov* as an upgrade of the present coherent harmonic generation (CHG) project at the DELTA storage ring*. EEHG allows to reach shorter wavelengths compared to the CHG scheme. In addition to the optical klystron used for CHG, a third undulator is needed for a second energy modulation of the electron bunch, followed by an additional strong dispersive section. Installing these insertion devices requires a new long straight section in the storage ring and a new lattice configuration. G. Stupakov Phys. Rev. Lett. 10², 074801 (2009) ** A. Schick et al., this conference

THPC081	Status of the Free-Electron Laser FLASH at DESY	FEL, photon, laser, radiation	3080
	M. Vogt, B. Faatz, J. Feldhaus, K. Honkavaara, S. Schreiber, R. Treusch DESY, Hamburg, Germany
	The free-electron laser facility FLASH at DESY, Germany has been upgraded in 2010. Now, FLASH delivers an electron beam energy up to 1.25 GeV. The longitudinal phase-space is linearized by 3.9 GHz superconducting cavities. The facility delivers to users ultra-short laser like radiation pulses in the range of less than 50 fs to 200 fs in the soft X-ray wavelenth range from 44 down to 4.1 nm. FLASH provides hundreds to thousands pulses per second to users with unprecedented peak brilliance. FLASH will be upgraded with a second undulator beam line and an additional experimental hall. Construction starts Autumn 2011. We summarize the operational status of the ongoing 3rd user period.

THPC082	Properties of the Radiation from the European X-ray Free Electron Laser	electron, FEL, radiation, emittance	3083
	E. Schneidmiller, M.V. Yurkov DESY, Hamburg, Germany
	Recent success of the Linac Coherent Light Source (LCLS) demonstrated feasibility for reliable production, compression, and acceleration of electron beams with emittances significantly smaller than original baseline parameters. The same scenario can be applied to the European XFEL as well. Experimental results from the Photo Injector Test Facility in Zeuthen (PITZ) demonstrated the possibility to generate electron beams with small charge and emittance. Computer modeling of the beam formation system also indicate on the possibility to preserve electron beam quality during acceleration and compression. Recently these trends have been analyzed, and baseline parameters of the European XFEL have been revised. Parameter space has been significantly extended in terms of the bunch charge. As a result, different modes of FEL operation become possible with essentially different properties of the radiation. In this paper we present an overview of radiation properties of SASE FEL radiators driven by electron beam with new baseline parameters.

THPC083	Analysis of Parameter Space of a Kilowatt-scale Free Electron Laser for Extreme Ultraviolet Lithography Driven by L-band Superconducting Linear Accelerator Operating in a Burst Mode	electron, radiation, FEL, laser	3086
	E. Schneidmiller, V. Vogel, H. Weise, M.V. Yurkov DESY, Hamburg, Germany
	The driving engine of the Free Electron Laser in Hamburg (FLASH) is an L-band superconducting accelerator. It is designed to operate in a burst mode with 800 microsecond pulse duration at a repetition rate of 10 Hz. The maximum accelerated beam current during the macropulse is 10 mA. In this paper we analyze the parameter space for optimum operation of the FEL at the wavelength of 13.5 nm and 6.7 nm. Our analysis shows that the FLASH technology holds great potential for increasing the average power of the linear accelerator and an increase of the conversion efficiency of the electron kinetic energy to the light. Thus, it will be possible to construct a FLASH like free electron laser with an average power up to 3 kW. Such a source meets the requirements of the light source for the next generation lithography.

THPC084	Optical Afterburner for a SASE FEL: First Results from FLASH	electron, radiation, FEL, resonance	3089
	M. Foerst CFEL, Hamburg, Germany M. Gensch HZDR, Dresden, Germany R. Riedel, E. Schneidmiller, N. Stojanovic, F. Tavella, M.V. Yurkov DESY, Hamburg, Germany
	Radiation Pulse from a Self-Amplified Spontaneous Emission Free Electron Laser (SASE FEL) consists out of spikes (wavepackets). Energy loss in the electron beam (averaged over radiation wavelength) also exhibits spiky behaviour on a typical scale of coherence length, and follows the radiation pulse envelope. These modulations of the electron beam energy are converted into large density (current) modulations on the same temporal scale with the help of a dispersion section, installed behind the x-ray undulator. Powerful optical radiation is then generated with the help of a dedicated radiator (afterburner). Envelope of the optical afterburner pulse is closely resembles the envelope of the x-ray pulse. We have recently demonstrated this principle at the Free Electron Laser in Hamburg (FLASH). We use THz undulator that is installed after the main X-ray as both dispersive element and radiator simultaneously. We characterize properties of the optical pulse using standard laser diagnostics techniques (i.e. FROG). Main result comes from the pulse duration measurement that we use to derive envelope of the x-ray radiation pulse duration which is in sub-100 fs range.

THPC086	Status Report on FERMI@Elettra Project	FEL, photon, linac, electron	3095
	F. Parmigiani, M. Svandrlik, D. Zangrando ELETTRA, Basovizza, Italy
	Funding: This work was supported in part by the Italian Ministry of University and Research under grants FIRB-RBAP045JF2 and FIRB-RBAP06AWK3 FERMI@Elettra, a single-pass FEL user-facility covering the wavelength range from 100 nm (12 eV) to 3 nm (413 eV) located next to the third-generation synchrotron radiation facility Elettra in Trieste, Italy is actually under completion and will start user operation next year. The first seeded lasing was observed in December 2010 and the first experiments have started this year. In this paper an overview of the present status of machine and beamlines systems will be given as well as a status about operation and future upgrade.

THPC089	Study of a Modified Quasi-periodic Undulator	radiation, photon, electron, insertion	3104
	A.L. Wu, Q.K. Jia USTC/NSRL, Hefei, Anhui, People's Republic of China
	To suppress high-order harmonic radiation effectively while maintain comparatively higher fundamental radiation intensity, a modified quasi-periodic undulator (QPU) which the magnet blocks have different size is studied in this paper. Then the paper also compares the radiation spectrum of various structural schemes. It is shown that the higher harmonic radiation of this new scheme will be suppressed more effectively than the conventional QPU.

THPC096	Soft X-ray Free-electron Laser with a 10-time Reduced Size	electron, FEL, bunching, laser	3113
	Y.-C. Huang, F.H. Chao, C.H. Chen, K.Y. Huang NTHU, Hsinchu, Taiwan P.J. Chou NSRRC, Hsinchu, Taiwan
	Funding: This work is supported by National Science Council under Contract NSC 99-2112-M-007 -013 -MY3. We present a 30-m long soft x-ray FEL consisting of a 5-MeV photoinjector, a 150 MeV linac, a magnetic chicane compressor, and a 3-m long undulator. We employ both the 3rd and the 4th harmoincs of a Nd laser at 355 and 266 nm, respectively, to illuminate the cathode of the photoinjector. Owing to the beating of the two lasers, the emitted electron beam is modulated at 282 THz. The electrons are further accelerated to 150 MeV and, after acceleration, compressed by 33 times in a magnetic chicane. The temporal compression of the electron macropulse increases the electron bunching frequency to 9.3 PHz, corresponding to a soft x-ray wavelength of 32.2 nm. We adopt a solenoid-derived staggered array undulator* with a 3-m length, 5 mm undulator period, and 1.2 mm gap. With a solenoid field of 10 kG, we estimate an undulator parameter of 0.4 and a corresponding radiation wavelength of 32.2 nm for a 150 MeV driving beam. With 3.3-kA peak current, 0.03% energy spread, 2 mm-mrad emittance, and 80-micron beam radius at the undulator entrance, the GENESIS code predicts 0.2 GW radiation power from the 3-m long undulator for an initial bunching factor of merely 10 ppm. * Y.C. Huang, H.C. Wang, R.H. Pantell, and J. Feinstein, "A staggered-array wiggler for far infrared, free-electron laser operation," IEEE J. Quantum Electronics 30 (1994) 1289.

THPC097	Transverse Alignment Tolerances for the European XFEL Laser Heater	laser, electron, FEL, emittance	3116
	V.A. Goryashko NASU/IRE, Kharkov, Ukraine M. Dohlus DESY, Hamburg, Germany M. Hamberg, V.G. Ziemann Uppsala University, Uppsala, Sweden
	Funding: Supported by the KTH-SU-UU FEL Center. We study the impact of misalignments between a laser beam and an electron bunch on the energy distribution function of the electron bunch in the laser heater. Transverse position and angular misalignment as well as different spot size of the laser and electron beam are considered. We find that the transverse misalignment makes the energy distribution function narrower compared to the case of ideal adjustment and a distinct peak in the distribution around the initial mean value of the energy appears. We demonstrate that despite these misalignments a uniform heating in terms of the energy spread can be achieved by appropriately adapting the transverse size and power of the laser beam such that the energy distribution function of the electron bunch at the end of the laser heater can be made similar to a Gaussian, thus providing more effective Landau damping against the micro-bunching instability. The laser power mainly determines the local energy spread while the laser spot size governs the shape of the energy distribution function. The transverse oscillations of electrons induced by the magnetic field in the laser heater are found to be non-essential for typical operation parameters.

THPC100	Full Temporal Reconstruction using an Advanced Longitudinal Diagnostic at the SPARC FEL	FEL, diagnostics, radiation, laser	3119
	G. Marcus, J.B. Rosenzweig UCLA, Los Angeles, California, USA M. Artioli, F. Ciocci, L. Giannessi, A. Petralia, M. Quattromini, V. Surrenti ENEA C.R. Frascati, Frascati (Roma), Italy A. Bacci, M. Bellaveglia, E. Chiadroni, G. Di Pirro, M. Ferrario, G. Gatti, A. Mostacci, A.R. Rossi INFN/LNF, Frascati (Roma), Italy A. Cianchi INFN-Roma II, Roma, Italy V. Petrillo Istituto Nazionale di Fisica Nucleare, Milano, Italy J.V. Rau ISM-CNR, Rome, Italy
	The Production of ultra-short (sub 100 fs) single-spike radiation possessing full longitudinal coherence from a free-electron laser (FEL) has been the subject of intense study. A Frequency-Resolved Optical Gating (FROG) diagnostic has been developed and tested at UCLA, which has the capability of providing a longitudinal reconstruction of these ultra-fast pulses. This paper reports the results of the application of the diagnostic at the SPARC FEL facility.

THPC101	Fitting Formulas for Space-charge Dominated Free-electron Lasers	FEL, space-charge, electron, simulation	3122
	G. Marcus, E. Hemsing, J.B. Rosenzweig UCLA, Los Angeles, California, USA
	A simple power-fit formula for calculating the gain length of the fundamental Gaussian mode of a free-electron laser having strong space-charge effects in the 3D regime has been obtained. This tool allows for quick evaluation of the free-electron laser performance in the presence of diffraction, uncorrelated energy spread, and longitudinal space-charge effects. Here, we use it to evaluate the performance of high-gain FEL amplifiers considered candidates as high average power light sources. Results are compared with detailed numerical particle simulations using the free-electron laser code Genesis.

THPC104	Optimization for Single-Spike X-Ray Fels at LCLS with a Low Charge Beam	laser, FEL, simulation, electron	3131
	L. Wang, Y.T. Ding, Z. Huang SLAC, Menlo Park, California, USA
	The recently commissioned Linac Coherent Light Source is an x-ray free-electron laser at the SLAC National Accelerator Laboratory, which is now operating at x-ray wavelengths of 20-1.2 Angstrom with peak brightness nearly ten orders of magnitude beyond conventional synchrotron sources. At the low charge operation mode (20 pC), the x-ray pulse length can be <10 fs. In this paper we report our numerical optimization and simulations to produce even shorter x-ray pulses by optimizing the machine and undulator setup. In the soft x-ray regime, with the help of slotted-foil or undulator taper, a single spike x-ray pulse is achievable with peak FEL power of 30 GW.

THPC106	Commissioning Status of the Fritz Haber Institute THz FEL	electron, FEL, linac, gun	3137
	A.M.M. Todd, H. Bluem, V. Christina, M.D. Cole, J. Ditta, D. Dowell, K. Jordan, R. Lange, J.H. Park, J. Rathke, T. Schultheiss, L.M. Young AES, Princeton, New Jersey, USA W. Erlebach, S. Gewinner, H. Junkes, A. Liedke, G. Meijer, W. Schöllkopf, G. von Helden FHI, Berlin, Germany S.C. Gottschalk STI, Washington, USA
	The THz Free-Electron Laser (FEL) at the Fritz Haber Institute (FHI) of the Max Planck Society in Berlin is designed to deliver radiation from 3 to 300 microns using a single-plane-focusing mid-IR undulator and a two-plane-focusing far-IR undulator that acts as a waveguide for the optical mode. A key aspect of the accelerator performance is the low longitudinal emittance, < 50 keV-psec, that is specified to be delivered at 200 pC bunch charge and 50 MeV from a gridded thermionic electron source. We utilize twin accelerating structures separated by a chicane to deliver the required performance over the < 20 - 50 MeV energy range. The first structure operates at near fixed field while the second structure controls the output energy, which, under some conditions, requires running in a decelerating mode. "First Light" is targeted for the centennial of the sponsor in October 2011 and we will describe progress in the commissioning of this device to achieve this goal. Specifically, the measured performance of the accelerated electron beam will be compared to design simulations and the observed matching of the beam to the mid-IR wiggler will be described.

THPC149	Development of PrFeB Cryogenic Undulator (CPMU) at SOLEIL	cryogenics, vacuum, permanent-magnet, storage-ring	3233
	C. Benabderrahmane, P. Berteaud, N. Béchu, L. Chapuis, M.-E. Couprie, J.P. Daguerre, J.-M. Filhol, C. Herbeaux, A. Lestrade, M. Louvet, J.L. Marlats, K. Tavakoli, M. Valléau, D. Zerbib SOLEIL, Gif-sur-Yvette, France
	A R&D programme for the construction of a 2 m long 18 mm period CPMU is under progress at SOLEIL. The cryogenic undulator will provide photons in the region of 1.4 to 30 keV. It will be installed in the next few months on the long straight section (SDL13) of the storage ring, and could be used later on to produce photons for the NANOSCOPIUM beamline. The use of PrFeB which features a 1.35 T remanence (Br) at room temperature enables to increase the peak magnetic field at 5.5 mm minimum gap, from 1.04 T at room temperature to 1.15 T at a cryogenic temperature of 77 K. Praseodymium was chosen instead of Neodymium magnetic material, because it is more resistant against the appearance of the Spin Reorientation Transition. Different corrections were performed first at room temperature to adjust the phase error, the electron trajectory and to reduce the multipolar components. The mounting inside the vacuum chamber enables the fitting of a dedicated magnetic measurement bench to check the magnetic performance of the undulator at low temperature. The results of the magnetic measurements at low temperature and the comparison with the measurement at room temperature are reported.

THPC150	Review of Insertion Device Dedicated to HIgh Energy Photons at SOLEIL	vacuum, photon, brightness, insertion	3236
	O. Marcouillé, C. Benabderrahmane, P. Berteaud, F. Briquez, L. Chapuis, M.-E. Couprie, T.K. El Ajjouri, F. Marteau, M. Valléau, J. Vétéran SOLEIL, Gif-sur-Yvette, France
	Producing high energy photons between 10 keV and 70 keV is a challenging topic in a medium energy storage ring. It requires up-to-date measurement techniques and specific Insertion Device (ID) technologies to produce high magnetic fields and short periods. SOLEIL (2.75 GeV) has designed and built eight conventional in-vacuum hybrid undulators operating at high radiation harmonics and also one small gap multipole wiggler to produce high magnetic field. The construction has been progressively improved by the choice of new magnetic materials of better quality and higher magnetization, additional correction techniques and mechanical changes. A 2-m long full scale cryogenic undulator made of PrFeB and vanadium permendur has been built, measured, corrected and is to be tested on the beam. An additional wiggler dedicated for Slicing experiments has been designed. The required magnetic field is high enough to also consider the ID as a good candidate for the production of hard X-ray photons. This paper presents the ID dedicated for the high energy photons and their spectral performances.

THPC151	The 65 mm Period Electromagnetic/Permanent Magnets Helical Undulator at SOLEIL	permanent-magnet, power-supply, electron, wiggler	3239
	F. Marteau, P. Berteaud, F. Bouvet, L. Chapuis, M.-E. Couprie, J.P. Daguerre, T.K. El Ajjouri, J.-M. Filhol, P. Lebasque, J.L. Marlats, A. Mary, K. Tavakoli SOLEIL, Gif-sur-Yvette, France
	SOLEIL prepares a new 65 mm period Electromagnetic/Permanent Magnets Helical Undulator (EMPHU), with a rapid switching at 5 Hz of the polarization required for dichroïsm experiments. The vertical field Bz is produced by coils fed by a fast switching power supply (designed and built in house), with a maximum current of 350 A and a polarity switching time shorter than 100 ms. The coils consist of 25 stacked copper layers shaped by water jet cutting. The current flows in 16 layers and 9 of them are cooled with thermal drain to a water piping. 4 additional power supplies feed 2 types of correction coils for the dynamic compensation of the field integrals, besides the ones for the termination. 1.28 T remanence NdFeB permanent magnets generate the horizontal field Bx. Peak Bz and Bx in the helical configuration reach 0.24 T at 14.7 mm minimum gap. Thermal modelling and measurements aim at keeping the magnet temperature constant. The static magnetic configuration was optimised using the ID_Builder software and the trajectory were checked for insuring a good reproducibility of the photon beam pointing when sweeping from one helicity to the other.

THPC152	Measurements of SOLEIL Insertion Devices using Pulsed Wire Method	insertion, insertion-device, wiggler, vacuum	3242
	M. Valléau, C. Benabderrahmane, M.-E. Couprie, O. Marcouillé, F. Marteau, J. Vétéran SOLEIL, Gif-sur-Yvette, France
	SOLEIL permanent magnets insertion devices are usually measured with a Hall probe in order to evaluate the electron angular deflexion, their deviation and the optical phase error, a figure of merit related to the quality of the insertion device radiation. A pulsed wire bench is developed at SOLEIL for reducing the measurement time of an undulator and for providing a measurement method without lateral access. A current pulse injected in a stretched wire inside the magnetic field area generates acoustic wave. The wire motion is detected by optical sensors whose signals are proportional to the local integral value. The signal-to-noise ratio of this method is often reduced due to several effects such as electronic noise, external and wire vibrations. However, following some hardware optimization it was possible to increase it up to almost 26 dB, making the method accurate and reproducible in order to realize efficient corrections. Measurements of first and second integral performed with Pulse wire, with Hall probe and with the electron beam are compared on three different types of insertions: an U18 in-vacuum cryogenic undulator, a HU60 APPLE-II undulator and a WSV50 in-vacuum wiggler.

THPC153	Recent Progress in Insertion Devices at the ESRF	multipole, insertion, insertion-device, quadrupole	3245
	J. Chavanne, G. Lebec, C. Penel, F. Revol ESRF, Grenoble, France
	Insertion Device activities at the ESRF are presently driven by the upgrade of more than ten beamlines. The concept of canted undulators is part of the requirements in a number of cases. Permanent Magnet Steerers (PMS) will be used to create canting angles of up to 5.4 mrad. The magnetic structure of PMS has been fully optimized to minimise space occupancy and magnetic perturbations induced on neighbouring undulators. The measured field quality of PMS recently constructed will be presented. The development of undulators dedicated to high photon energy is still being pursued. Following on from the successful operation since 2008 of a first Cryogenic Permanent Magnet Undulator (CPMU) installed in the ID6 beamline, a second device has been constructed. This 2 m long device has a period of 18 mm and will be operated at 145 K. The field measurements at cryogenic temperature are discussed hereafter.

THPC154	Shimming of the Dynamic Field Integrals of the BESSY II U125 Hybrid Undulator	wiggler, permanent-magnet, electron, injection	3248
	J. Bahrdt, W. Frentrup, A. Gaupp, M. Scheer, I. Schneider, G. Wüstefeld HZB, Berlin, Germany
	Within a continuous program the BESSY II undulators are prepared for Topping-Up operation. The BESSY II U125 planar hybrid undulator has a period length of 125 mm and a pole width of only 60 mm. The horizontal defocusing of the 1.7 GeV e-beam may result in a significant reduction of the horizontal dynamic aperture, reducing the injection efficiency when injecting into the closed gap. The dynamic field integrals are derived from a 2D-Fourier decomposition of the 3D-field. An analytic description of the dynamic multipoles based on the Fourier coefficients is presented. Magic fingers have been installed in order to minimize the dynamic field integrals and to enlarge the good field region of the device.

THPC155	Modification of the BESSY II Optic for the Implementation of a Small Gap Undulator	optics, cryogenics, quadrupole, sextupole	3251
	J. Bahrdt, K.B. Bürkmann-Gehrlein, V. Dürr, W. Frentrup, A. Gaupp, A. Jankowiak, P. Kuske, J. Rahn, M. Scheer, P.O. Schmid, G. Wüstefeld HZB, Berlin, Germany
	At BESSY there is an increasing demand for photons in the range from 60 eV to 8 keV available at the same experimental station. The photons will be produced by a combination of two adjacent undulators, one of them will be a small period cryogenic undulator. Several optics schemes for the 1.7 GeV BESSY II storage ring are discussed to install the undulators. Two types of straight sections exist. A high beta straight with betax_min=15 m and betay_min=4.5 m and a low beta straight with betax_min=betay_min=1 m. We discuss the present plan, which clearly favours a small detuning of an existing low beta straight to shift the low beta waist to the centre of the low gap undulator, with only minor impact to the machine.

THPC156	Performance of the PETRA III APPLE II Undulator	multipole, storage-ring, closed-orbit, optics	3254
	J. Bahrdt, W. Frentrup, A. Gaupp, M. Scheer HZB, Berlin, Germany K. Balewski, J. Keil, A. Schöps, M. Tischer DESY, Hamburg, Germany
	A 5m-long APPLE II undulator has been built in collaboration between Helmholtz-Zentrum Berlin and DESY Hamburg. Magnetic field measurements after the final shimming in the laboratory are presented. The device has been installed in the storage ring and machine studies have been performed. The tune shifts in the elliptical and the inclined mode are in agreement with predictions from theory. The dynamic field integrals have successfully been minimized in the storage ring with so-called L-shims (rectangular iron sheets) which are placed at the undulator center at the magnet edges.

THPC157	Hot-/Cold-Side Characterization of Asymmetric Undulator Magnets	permanent-magnet, magnet-design, induction, insertion	3257
	F.-J. Börgermann Vacuumschmelze GmbH & Co. KG, Hanau, Germany S. Marks LBNL, Berkeley, California, USA
	The homogeneity of permanent magnets for use in undulators is dominantly described by small variations in remanence (±1%) and magnetic angles (±1°). The definition and measurement of the so-called hot-/cold-side-effect has proven to be useful as characterization of higher order variations of the local field components. It is measured by a Hall probe at a distance of the half gap width from both magnet pole-surfaces. Typical results for a batch of magnets lie in a range of about ±2% or less. For symmetrical permanent magnet geometries, the distribution is symmetric about the value of zero. In a batch of magnets for a new EPU at LBNL, however, we found an asymmetric distribution of the hot-/cold-side-effect. This asymmetry is attributed to the geometrically asymmetric cut-outs inside the magnets used for fixture on the aluminum keepers. We present a theoretical model which can predict this asymmetric influence on the hot-/cold-side-effect resulting from these small geometric asymmetries. The method may also be used to pre-calculate corrected specification values for the near-field results for future undulator magnets.

THPC158	Field Optimization for Short Period Undulators	wiggler, permanent-magnet, insertion, damping	3260
	P. Peiffer, A. Bernhard KIT, Karlsruhe, Germany R. Rossmanith Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany D. Schoerling CERN, Geneva, Switzerland
	Undulators dedicated to low energy electron beams, like Laser Wakefield Accelerators, require very short period lengths to achieve X-ray emission. However, at these short period lengths (~5 mm) it becomes difficult to reach magnetic field amplitudes that lead to a K parameter of ~1, which is generally desired. Room temperature permanent magnets and even superconductive undulators using Nb-Ti as conductor material have proven insufficient to achieve the desired field amplitudes. The superconductor Nb3Sn has the theoretical potential to achieve the desired fields. However, up to now it is limited by several technological challenges to much lower field values than theoretically predicted. Alternatives for higher fields would be to manufacture the poles of the undulator body from Holmium instead of iron or to use Nb-Ti wires with a higher superconductor/copper ratio. The advantages and challenges of the different options are compared in this contribution.

THPC160	A Superconducting Switch for Insertion Devices with Variable Period Length	insertion, insertion-device, power-supply, wiggler	3266
	T. Holubek, T. Baumbach, S. Casalbuoni, S. Gerstl, A.W. Grau, M. Hagelstein, D. Saez de Jauregui Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany C. Boffo, W. Walter BNG, Würzburg, Germany
	Superconducting insertion devices (IDs) are very attractive for synchrotron light sources since they offer the possibility to enhance the tuning range and functionality significantly by period length switching. Period length switching can be realized by employing two or more individually powerable subsets of superconducting coils and by reversing the current in a part of the winding. So far, the first demonstration mock-up coil allowing period length tripling was fabricated and tested successfully. Here, we report on the feasibility of a superconducting switch operating at 4.2 K, immersed in a liquid Helium bath as well as under conduction cooled conditions.

THPC161	Possible Superconducting Insertion Devices with Period Length Doubling for Beamlines of Third Generation Light Sources	simulation, insertion, insertion-device, photon	3269
	D. Saez de Jauregui, T. Baumbach, S. Casalbuoni, S. Gerstl, A.W. Grau, M. Hagelstein, T. Holubek Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
	The tunability of an insertion device can be increased by period length switching, which in superconducting insertion devices (IDs) can be achieved by reversing the current in separately powered subsets of the superconducting windings. The feasibility of this concept has been experimentally proven. We study here different possibilities to tailor the needs of beamlines of third generation light sources: FEM simulations performed to compute the magnetic field on axis of such devices with different period lengths are reported together with the spectral simulations.

THPC162	Possible Application of NbTi Wire with Artificial Pinning Centres for Insertion Devices	brilliance, insertion, insertion-device, vacuum	3272
	T. Holubek, S. Casalbuoni, S. Gerstl, A.W. Grau, D. Saez de Jauregui Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany M. Klaeser, T. Schneider FZ Karlsruhe, Karlsruhe, Germany L. Motowidlo SupraMagnetics, Inc., Plantsville, USA
	Superconductive insertion devices (IDs) allow higher fields for a given gap and period length compared to the classical permanent magnet IDs. This technological concept permits to increase the brilliance and/or the photon energy. The working horse for superconducting magnets are multifilament NbTi wires, which are nowadays also used for superconducting insertion devices. Even higher magnetic fields can be reached by using a conductor with enhanced critical current density. Here, we propose a possible application for superconducting undulators, wound with NbTi wire with artificial pinning centres, developed by SupraMagnetics, Inc. We report the critical current characteristic, Jc(B), of short wire measured in a liquid helium bath, and the load-line of a racetrack coil, designed to simulate the field configuration on the conductor as in a superconducting undulator. Based on the measured load-line we report the simulations of the magnetic field on axis and of the spectrum in a third generation light source of a possible undulator wound with a wire having similar properties of the measured one.

THPC163	Local and Integral Field Measurement Setup for 2m Long Superconducting Undulator Coils	factory, synchrotron, insertion, insertion-device	3275
	A.W. Grau, T. Baumbach, S. Casalbuoni, S. Gerstl, M. Hagelstein, T. Holubek, D. Saez de Jauregui Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
	The performance of superconducting insertion devices depends strongly on their magnetic field quality. It is of fundamental importance to characterize the magnetic properties of insertion devices accurately before installation in synchrotron light sources. Thus a main part of the R&D program for superconducting insertion devices at the Karlsruhe Institute of Technology focuses on quality assessment. This contribution describes the instrumentation to perform magnetic measurements of the local field, of the field integrals and of the multipole components of superconducting undulator coils in a cold in vacuum (cryogen free) environment. It focuses on the outcome of the factory acceptance test together with results of first field measurements performed with mock-up coils.

THPC164	Phase Shifters for the FERMI@Elettra Undulators	electron, FEL, radiation, polarization	3278
	B. Diviacco, R. Bracco, D. Millo, M.M. Musardo ELETTRA, Basovizza, Italy
	The variable gap undulator system in operation at the FERMI@Elettra Free Electron Laser facility requires adjustable phase matching devices between consecutive radiator segments in order to maintain optimal lasing conditions while changing the radiation properties. A permanent magnet phase shifter has been designed to achieve the required electron beam delay in a compact structure that could be installed in close proximity to the undulators. In this paper we present the design of the phasing units and the results of the magnetic measurements performed on the five devices installed so far. We also describe the method used to properly set their field strength for any given electron energy, radiation wavelength and polarization.

THPC165	Estimations for Demagnetization of ID Permanent Magnets due to Installation of OTR	electron, permanent-magnet, radiation, simulation	3281
	Y. Asano RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan T. Bizen JASRI/SPring-8, Hyogo, Japan
	Demagnetization due to high energy electron irradiation is one of the crucial issues for stable operation of X-ray free electron laser (XFEL) and Synchrotron radiation (SR) facilities. Especially, during the commissioning, electron beam is scattered and then hits permanent magnets of insertion devices due to installation of some instrumentations such as OTR (Optical Transition Radiation) for beam diagnosis so that the estimation of demagnetization is very important to perform the commissioning smoothly. Fortunately, we found the index of demagnetization of Nd2Fe14B permanent magnets due to high energy electron irradiation. Star density produced by high energy photo-neutron reproduces experimental results of demagnetization. At SPring-8, in-vacuum type undulators have been employed for XFEL so that we estimate the demagnetization of the undulators for various cases such as electron energy in ranging from 2 GeV to 8 GeV and the permanent magnet gap from 2 mm to 40 mm. And we also estimate the allowable time to be able to insert the OTR.

THPC166	Design Consideration of New Insertion Devices of Hefei Light Source	vacuum, photon, radiation, insertion	3284
	Q.K. Jia USTC/NSRL, Hefei, Anhui, People's Republic of China
	To meet the requirements of users for higher brilliance and good transverse coherence VUV and soft X-ray synchrotron radiation, Hefei Light Source(HLS) will be upgraded. After upgrade HLS will have smaller beam emittance and install more insertion devices. In this paper the design considerations of new insertion devices are reported, they include one elliptically polarizing undulator, one quasi-periodic undulator, one in-vacuum undulator and one wiggler.

THPC167	The Design of Dual Canted In-vacuum Undulators at SSRF	vacuum, radiation, ion, synchrotron	3287
	X. Hu, L. Yin, Q.G. Zhou SINAP, Shanghai, People's Republic of China
	Funding: National foundation for scientific infrastructure, Development and Reform Commission of China. Five new beamlines are under design and construction at SSRF to supply the synchrotron radiation for the structural biology research in the protein project. Two in-vacuum undulators with canted angle of 6mrad are arranged in a 6.5m long straight section in order to keep the potential to accommodate more beamlines for the future. Limited by the length of the straight section and the angle between two beamlines, the layout design in the straight section is rather difficult to satisfy the required photon flux to the beamline and keep the normal design of the undulator. Many main components will be redesigned in this section on the base of existing ones, including in-vacuum undulator, correction magnet, RF bellows, photon absorbers and so on. In this paper the layout design and the modified design for some key components are described.

THPC168	Field Error Correction for a Superconducting Undulator	photon, radiation, electron, simulation	3290
	S. Chunjarean PAL, Pohang, Kyungbuk, Republic of Korea C.-S. Hwang, J.C. Jan NSRRC, Hsinchu, Taiwan H. Wiedemann SLAC, Menlo Park, California, USA
	To reach higher photon energies in the region of soft or hard x-rays with high photon beam brightness in low energy storage rings, superconducting undulators with very short period length and high magnetic field strength are required. Because undulator radiation comes in a line spectrum, photons up to the 7th harmonic are desired. The photon brightness in such harmonics is strongly dependent on perfect periodicity of the magnetic field. Such imperfections also appear in conventional permanent material undulators, which can be corrected by well developed and efficient shimming. Unfortunately, this method cannot be applied to superconducting undulators. Therefore, we present a new approach to field corrections by modification of the magnetic field saturation in each pole. In this paper it is shown that this approach can reduce not only the magnetic field error but also greatly improves phase errors from period to period. The proposed method works quite local with only small perturbations in neighboring poles. The tenability is preserved for most of the field excitations and is reduced only at extreme parameters.

THPC169	Short-Period RF Undulator for a Nanometer SASE Source	electron, cavity, injection, radiation	3293
	S.V. Kuzikov, M.E. Plotkin, A.A. Vikharev IAP/RAS, Nizhny Novgorod, Russia J.L. Hirshfield Yale University, Physics Department, New Haven, CT, USA T.C. Marshall, G.V. Sotnikov Omega-P, Inc., New Haven, Connecticut, USA
	Funding: Sponsored in part by US Department of Energy, Office of High Energy Physics. A room-temperature RF undulator to produce ~1 nm wavelength radiation using a relatively low energy electron beam (0.5 GeV) is considered. The design features include an effective undulator period of 0.45 cm, an undulator parameter of K = 0.4, an effective field length of 50 cm. These parameters could be be realized using a multi-MW RF power amplifier to drive the undulator (e.g., the 34 GHz pulsed magnicon at Yale or a 30 GHz gyroklystron at IAP) with microsecond pulse duration. Two undulator designs were considered that avoid problems with a co-propagating wave: a dual-mode cylindrical cavity [TE01 (counter propagating) - TE02 (co-propagating)] with an off-axis electron beam; and a traveling HE11 mode resonant ring with an on-axis beam.

THPC170	Magnetic Characterization of FEL-2 Undulators for the FERMI@Elettra Free-electron Laser	FEL, multipole, sextupole, quadrupole	3296
	M. Kokole KYTE, Sezana, Slovenia B. Diviacco ELETTRA, Basovizza, Italy T. Milharcic, M. Zambelli KYMA, Trieste, Italy G. Soregaroli, M. Tedeschi Euromisure srl, Pieve S. Giacomo (Cremona), Italy
	Kyma Srl is the spin-off company of Sincrotrone Trieste, Elettra laboratory, set up in 2007 together with the two industrial partners Cosylab d.d. and Euromisure SpA, in order to design and manufacture the undulators for the FERMI@Elettra project in Trieste, Italy. The insertion devices, for FEL-2 line, manufactured and characterized so far are the following: Modulator, 3.2 m linearly polarized undulator, three 55.2 mm APPLE-II variable polarization undulators, each 2.4 m long and six 34.8 mm APPLE-II undulators also each 2.4 m long. All the above devices have been characterized, both from the mechanical and the magnetic point of view. The measured parameters are in good agreement with the design values. This paper presents the most relevant changes in design from FEL-1 to FEL-2 line and results of the magnetic measurements carried out on all the above undulators.

THPC171	Performance of ID at ALBA	vacuum, wiggler, storage-ring, insertion	3299
	J. Campmany, J. Marcos, V. Massana CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	The new synchrotron light source ALBA is currently being commissioned along with the first phase of beamlines. Up to 6 beamlines are using light produced by Insertion Devices. There are up to four types of IDs: 2 Apple-II undulators (EU62 and EU71) operating at low energies, one conventional wiggler (MPW80) operating in the range of 2 – 20 keV, two in-vacuum undulators (IVU21) operating in the range 5 – 30 keV and a superconducting wiggler (SCW30) operating in the range of 40 keV. Installation of the IDs has been done in two steps. First, the out-vacuum devices (EU62, EU71 and MPW80) have been mechanically installed. Initial commissioning of Storage Ring has been done with their gaps opened to maximum value. Then, their gap has been closed to study the effect in the beam dynamics. In the second step, the in-vacuum devices (both IVU21 and the SCW30) have been installed and tested. In this paper we present the first results and performances of the insertion devices obtained both in Site Acceptance Test and during the first months of commissioning with beam.

THPC173	Modelization of Inhomogeneities in Permanent Magnet Blocks	permanent-magnet, insertion, insertion-device, simulation	3305
	V. Massana, J. Campmany, J. Marcos CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	Nowadays one of the main objectives for insertion devices manufacturers is to reduce the gap of undulators as much as possible while keeping the features of the generated magnetic field. Because of that, the effects of magnetic blocks’ inhomogeneities are playing an increasing role in the quality of the whole device. In this paper we present a modelization of the inhomogeneities of permanent magnet blocks used to build wigglers and undulators. The model is based in splitting individual magnet blocks in different parts which are considered magnetically homogeneous. The model takes into account the relative orientation of magnet blocks assembled into their holders as well as local magnetic properties. We have applied the model to fit magnetic field integrals measured with a fixed stretched wire bench and magnetization data obtained from Helmholtz coils measurements for both single blocks and groups of blocks mounted on a common holder. The results of the model fit with experimental data within an rms error of 6•10^-4 mT•m for individual blocks and 1.5•10^-4 mT•m in the case of magnet groups.

THPC174	Manufacturing and Testing of the First Phase Shifter Prototypes Built by CIEMAT for the European-XFEL	controls, electron, free-electron-laser, laser	3308
	I. Moya, J. Calero, J.M. Cela-Ruiz, L. García-Tabarés, A. Guirao, J.L. Gutiérrez, L.M. Martinez Fresno, T. Martínez de Alvaro, E. Molina Marinas, A.L. Pardillo, L. Sanchez, S. Sanz, F. Toral, C. Vazquez, J.G.S. de la Gama CIEMAT, Madrid, Spain
	Funding: Work partially supported by the Spanish Ministry of Science and Innovation under SEI Resolution on 17-September-2009. The European X-ray Free Electron Laser (EXFEL) will be based on a 10 to 17.5 GeV electron linac. Its beam will be used in three undulator systems to obtain ultra-brilliant X-ray flashes from 0.1 to 6 nanometres for experimentation. The undulator systems are formed by 5m long undulator segments and 1.1m long intersections in between. They accommodate a quadrupole on top of a precision mover, a beam position monitor, two air coil correctors and a phase shifter. The function of the phase shifter is to adjust the phase of the electron beam with respect to that of the radiation field when the wavelength is changed by tuning the gap. In this context, CIEMAT will deliver 92 phase shifters, as part of the Spanish in-kind contribution to the EXFEL project. This paper describes the engineering design, the manufacturing techniques and the mechanical and magnetic tests realized on the first prototypes.

THPC175	Spectral Analysis of Arbitrary Strength Parameter for Various Insertion Devices	photon, wiggler, insertion, insertion-device	3311
	S.D. Chen, T.M. Uen NCTU, Hsinchu, Taiwan C.-S. Hwang NSRRC, Hsinchu, Taiwan
	An insertion device (ID) with medium strength parameter was hard to be defined as a wiggler or an undulator. Usually, this kind of ID was classified according to the user’s definition and to select the spectrum calculation formula of wiggler or undulator. The spectrum calculation formula for wiggler or undulator is quite difference and consequently obtain a big different flux density by using the same strength parameter. So, it is no way that the spectrum calculation of them is consistent. Therefore, a universal formula will be developed for the spectrum analysis for the different kinds of insertion devices that is with large different strength parameter (deflection parameter). Consequently, a modified spectrum calculation formula of ID with medium strength parameter was studied by reviewing the difference of existing spectrum formulas. The familiar formula of calculating undulator spectrum was modified and can be used on ID with arbitrary strength parameter. The algorithm of formula modification was described. Some relative issue, like the effect of phase error and energy spread, and taper undulator were also discussed herein.

THPC176	Progress in Insertion Devices for TPS in Phase I	insertion, insertion-device, photon, vacuum	3314
	C.H. Chang, C.-H. Chang, J.C. Huang, C.-S. Hwang, C.K. Yang NSRRC, Hsinchu, Taiwan
	Taiwan Photon Source (TPS) with beam energy 3 GeV and beam current 500 mA is a third-generation synchrotron radiation facility of medium energy. In the initial commissioning stage of TPS, the machine will be equipped with ten insertion devices (ID) and serve seven beamlines in phase I. Of these, three long straight sections configured as a double-minimum betay function lattice design with minimized beam influence of emittance are used for the installation of a pair of insertion devices in a straight section, two undulators of APPLE-II type and four in-vacuum undulators (IU), to produce great brilliance and coherent X-rays with great flux. The details of these insertion devices are explained herein.

THPC177	Field Correction Results from NSRRC Elliptically Polarized Undulator 46	kicker, electron, multipole, synchrotron	3317
	J.C. Huang, C.-H. Chang, C.-S. Hwang, C. JunTune, F.-Y. Lin NSRRC, Hsinchu, Taiwan
	Elliptically polarized undulator (EPU) is a common insertion device to use in storage ring in order to provide circular polarization. The field correction is an essential step for EPU construction, and it can prevent the photon flux reduction from idea case and electron beam trajectory and exit angle from EPU. The conventional field correction method is tedious works and strongly based on experiences. An initial state of NSRRC EPU46 has phase error over 40 degrees, and many difficulties on field correction to reduce the phase error under 5 degrees. This paper will describe the detailed magnetic field correction process and practical results from in NSRRC EPU.

THPC178	Superconducting Planar Undulator Development in the UK	cryogenics, cryomodule, vacuum, radiation	3320
	J.A. Clarke, D.J. Scott, B.J.A. Shepherd STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom V. Bayliss, T.W. Bradshaw, A.J. Brummitt, G.W. Burton, M.J.D. Courthold, M.J. Hills, S.R. Watson, M.L. Woodward STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
	Superconducting undulators promise higher peak fields on axis than any other technology but they are still not a mainstream solution for 3rd or 4th generation light sources. A team within the UK is developing the design of a short period, narrow aperture, superconducting undulator that is planned to be installed and tested in the Diamond Light Source (DLS) in 2014. This paper will describe the main parameters of the undulator and the key design choices that have been made. Recent progress is then described in the areas of magnet modelling, mechanical design, cryogenic design, and prototyping. Finally, the next steps are described.

THPC179	Electron Beam Heating and Operation of the Cryogenic Undulator and Superconducting Wigglers at Diamond	electron, wiggler, cavity, synchrotron	3323
	J.C. Schouten, E.C.M. Rial Diamond, Oxfordshire, United Kingdom
	Diamond Light Source has two superconducting wigglers and one cryocooled undulator installed serving three beam lines. The cryocooled undulator (cpmu) has been operating since August 2010 while the superconducting wigglers have been operating for more than 4 years (SCW-1) and 2 years (SCW-2). We will report on the first year of operation of the cpmu including details of its spectral output and cryogenic performance. Our experience of the cooling system and measures taken to ensure reliability and to minimize the risks of a prolonged downtime are also presented. The two superconducting wigglers are exposed to a high heat load due to the beam heating of the inner liner. Until recently this resulted in a much higher helium consumption than specified and so recently a new liner has been fitted to SCW-1 and new re-condensers to SCW-2. In addition a thermal bridge has been made between the RF tapers and the outer heat shield of both SCW-1 and SCW-2. The results of these improvements will be presented.

THPC183	Application of the Balanced Hybrid Mode in Overmoded Corrugated Waveguides to Short Wavelength Dynamic Undulators	cavity, impedance, FEL, electron	3326
	S.G. Tantawi, G.B. Bowden, C. Chang, J. Neilson, M. Shumail SLAC, Menlo Park, California, USA C. Pellegrini UCLA, Los Angeles, California, USA
	Funding: Work Supported by the US Department of Energy Inspired by recent developments in low-loss overmoded components and systems for ultra-high power RF systems, we explored several overmoded waveguide systems that could function as RF undulators. One promising structure is a corrugated waveguide system operating at the hybrid HE11 mode. This is a new application for that mode. Initial calculations indicate that such a system can be operated at relatively low power levels while obtaining large values for the undulator parameters. RF surface fields are typically low enough to permit superconducting operation. This technology could realize an undulator with short wavelengths and also dynamic control of the undulator parameters including polarization. We introduce the scaling laws governing such a structures, and then show with exact simulations an undulator design that have a wavelength of about 1.4 cm with an undulator parameter K~1. This undulator is intended to be powered by a 50 MW source at a frequency of 11.4 GHz. We describe the experimental setup for testing such a technology.

THPC184	Progress of the Coherent Soft X Ray Straight Section at NSLS-II	electron, photon, polarization, insertion	3329
	C.A. Kitegi, P. Cappadoro, O.V. Chubar, T.M. Corwin, D.A. Harder, P. He, Y. Li, C. Meyer, G. Rakowsky, J. Rank, C. Rhein, C.J. Spataro, T. Tanabe BNL, Upton, Long Island, New York, USA
	The National Synchrotron Light Source II (NSLS-II) is the new light source under construction at Brookhaven National Laboratory (BNL). The Coherent Soft X rays beam line (CSX) is one of the six beamlines included in the baseline project. Following the request of CSX scientists for a source providing adjustable polarized radiation from 160 eV to 1.7 keV, two Advanced Planar Polarized Light Emitter II (APPLE-II)-type undulators will be installed in a 6.6 m long straight section. Each device is 2 m long, the period is 49.2 mm and the minimum gap is 11.5 mm. The different operation modes of the beamline and the layout of the straight section are reviewed here.

THPC186	Heat Load for the APS Superconducting Undulator	photon, radiation, simulation, shielding	3332
	L.E. Boon, A.F. Garfinkel Purdue University, West Lafayette, Indiana, USA K.C. Harkay ANL, Argonne, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The APS Upgrade calls for the development and commissioning of a superconducting undulator (SCU) at the Advanced Photon Source (APS), a 7-GeV electron synchrotron. The first SCU will be installed in June 2012. Until then, simulations such as SYNRAD3D will be used to understand and reduce the heat load on the cryo-system from primary and secondary photons. Current calculations predict that primary photons will distribute 0.5W/m on the chamber walls of the cryostat. SYNRAD3D will be used to calculate the ratio of primary and secondary photons to calculate the heat load due to secondary photons. Previous simulations were of only one sector of the APS accelerator. Simulated here are multiple sectors, to include photons back scattered from downstream photon absorbers.

Paper

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Other Keywords

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MOYCA01

Status Report on the Commissioning of the Japanese XFEL at SPring-8

laser, acceleration, electron, FEL

21

H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

The Japanese XFEL at SPring-8, which was named SACLA (Spring-8 Angstrom Compact free electron LAser), was completed in FY2010. After RF full-power aging for about four months the beam commissioning of SACLA has been started since 21 February 2011. About one month later, in 23 March a design beam energy of 8 GeV was achieved and a spontaneous undulator radiation of 0.8 Angstrom was observed at the beam-line optical hutch by closing XFEL undulator gaps down to 5 mm in full-width. The beam commissioning has proceeded smoothly and since the middle of April we have entered to a tuning phase towards SASE lasing, which is at least one month ahead of schedule. This talk will report the beam commissioning overview of SACLA including SASE XFEL performance, key tuning-processes and critical issues for achieving the lasing.

Slides MOYCA01 [37.840 MB]

MOOCB02

Commissioning and Performance of the Beam Monitor System for XFEL/SPring-8 “SACLA”

cavity, electron, bunching, FEL

47

Y. Otake, C. Kondo, H. Maesaka
RIKEN Spring-8 Harima, Hyogo, Japan
H. Ego, S. Matsubara, T. Matsumoto, T. Sakurai, H. Tomizawa, K. Yanagida
JASRI/SPring-8, Hyogo-ken, Japan
S.I. Inoue
SES, Hyogo-pref., Japan

The construction of a beam monitor system for XFEL/SPring 8 “SACLA” was completed. The system was developed to realize a spatial resolution of less than 3 um to align a beam orbit for an undulator section with about 100 m long and a temporal resolution to measure bunch lengths from 1 ns to 30 fs to maintain a constant peak beam current conducting stable SASE lasing. The system principally comprises cavity type beam position monitors (BPM), current monitors (CT), screen monitors (SCM) and bunch length measurement instruments, such as an rf deflector and CSR detectors. Commissioning of SACLA started from March 2011, and the monitors performed sufficient roles to tune beams for the lasing. The achieved over-all performances of the system including DAQ are: the BPM have spatial resolution of 300 nm, the bunch length monitors observe bunch lengths from 1ns in an injector with velocity bunching to less than 30 fs after three-stage bunch compressors. The less than a 3 um spatial resolution of the SCM was also confirmed in practical beam operation. By these fulfilled performances, the stable lasing of SACLA will be achieved. This report describes commissioning, performance of the system.

Slides MOOCB02 [7.516 MB]

MOPC039

Optimization of IH-DTL Resonator for UNDULAC-RF

acceleration, impedance, focusing, ion

160

S.M. Polozov, A.S. Plastun, P.R. Safikanov
MEPhI, Moscow, Russia

The linear undulator accelerator (UNDULAC) was proposed early for ribbon ion beam acceleration*. UNDULAC can be realized using two non-synchronous spatial harmonics. One of them must be RF field harmonic and the second can be RF (UNDULAC-RF) or electrostatic (UNDULAC-E). The acceleration mechanism in UNDULAC is similar as inverse free electron laser (IFEL). The beam dynamics in both types of UNDULAC was studied early and the design of UNDUAC-RF resonator was started in **. Design of the 150 MHz IH-DTL for UNDULAC-RF will present. The optimization of the longitudinal field distributions will do. The most effective construction will show. Transverse electric field distributions within drift tube will optimize by blending support stems and drift tubes.
* E.S. Masunov, Sov. Phys. – Tech. Phys. 35(8), 962-965, 1990.
** S. M. Polozov, P. R. Safikanov, Proc. IPAC’10, Kyoto, Japan, p. 3762 (2010).

MOPO016

Commissioning Tune Feedback in the Taiwan Light Source

feedback, insertion, insertion-device, controls

517

C.H. Kuo, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.-Y. Liao, C.Y. Wu
NSRRC, Hsinchu, Taiwan

The tune control is important parameter in the insertion devices operation. There are many difference type insertion devices are disturbed in the storage ring of TLS. The traditional feed-forward control to correct orbit change and tune shift that isn’t enough when difference type insertion devices are operated with various condition. The tune feedback is used to solve the tune change problem. The stable tune measurement is necessary in the stable storage ring. There are various excited bunch train methods to get stable tune that will be also discussed in this report.

TUZA01

Commissioning and Initial Operation of FERMI@Elettra

FEL, electron, laser, photon

918

S. Di Mitri, E. Allaria, R. Appio, L. Badano, S. Bassanese, F. Bencivenga, A.O. Borga, M. Bossi, E. Busetto, C. Callegari, F. Capotondi, K. Casarin, D. Castronovo, P. Cinquegrana, D. Cocco, M. Cornacchia, P. Craievich, R. Cucini, I. Cudin, G. D'Auria, M.B. Danailov, R. De Monte, P. Delgiusto, A.A. Demidovich, B. Diviacco, A. Fabris, R. Fabris, W.M. Fawley, M. Ferianis, S. Ferry, V. Feyer, L. Fröhlich, P. Furlan Radivo, G. Gaio, F. Gelmetti, L. Giannessi, R. Gobessi, R. Ivanov, E. Karantzoulis, M. Kiskinova, M. Lonza, A.A. Lutman, C. Masciovecchio, R.H. Menk, M.M. Milloch, M.M. Musardo, I. Nikolov, S. Noe, F. Parmigiani, L. Pavlovič, E. Pedersoli, G. Penco, M. Petronio, M. Predonzani, E. Principi, E. Quai, G. Quondam, F. Rossi, L. Rumiz, C. Scafuri, C. Serpico, P. Sigalotti, C. Spezzani, M. Svandrlik, C. Svetina, M. Trovò, A. Vascotto, M. Veronese, R. Visintini, D. Wang, M. Zaccaria, D. Zangrando
ELETTRA, Basovizza, Italy
M. Alagia, A. Kivimaki, M. Zangrando, M. de Simone
IOM-CNR, Trieste, Italy
L. Avaldi, P. Bolognesi, M. Coreno, P. O’Keeffe
CNR - IMIP, Trieste, Italy
M. Dal Forno
DIEIT, Trieste, Italy
G. De Ninno, S. Spampinati
University of Nova Gorica, Nova Gorica, Slovenia
M. Devetta, T. Mazza, P. Piseri
Università degli Studi di Milano, Milano, Italy
E. Ferrari
Università degli Studi di Trieste, Trieste, Italy
S. Stranges
Università di Roma "La Sapienza", Roma, Italy

Funding: Work was supported in part by the Italian Ministry of University and Research under grants FIRB-RBAP045JF2 and FIRB-RBAP06AWK3.
This article describes the design goals of FERMI@Elettra, reports on the goals achieved so far and shows how the facility development has been driven by the new research frontier of ultra-fast, extreme ultra-violet and soft X-ray science. The commissioning phases and first experience with user pilot experiments are presented and discussed.

Slides TUZA01 [13.401 MB]

TUZA02

sFLASH - Present Status and Commissioning Results

electron, laser, FEL, radiation

923

V. Miltchev, S. Ackermann, A. Azima, J. Bödewadt, F. Curbis, M. Drescher, E. Hass, Th. Maltezopoulos, M. Mittenzwey, J. Rönsch-Schulenburg, J. Roßbach, R. Tarkeshian
Uni HH, Hamburg, Germany
H. Delsim-Hashemi, K. Honkavaara, T. Laarmann, H. Schlarb, S. Schreiber, M. Tischer
DESY, Hamburg, Germany
R. Ischebeck
PSI, Villigen, Switzerland
S. Khan
DELTA, Dortmund, Germany

The free-electron laser in Hamburg (FLASH) was previously being operated in the self-amplified spontaneous emission (SASE) mode, producing photons in the XUV wavelength range. Due to the start-up from noise the SASE-radiation consists of a number of uncorrelated modes, which results in a reduced coherence. One option to simultaneously improve both the coherence and the synchronisation between the FEL-pulse and an external laser is to operate FLASH as an amplifier of a seed produced using high harmonics generation (HHG). An experimental set-up - sFLASH, has been installed to test this concept for the wavelengths below 40 nm. The sFLASH installation took place during the planed FLASH shutdown in the winter of 2009/2010. The technical commissioning, which began in the spring of 2010, has been followed by seeded-FEL commissioning, FEL-characterisation and pilot experiments. In this contribution the present status and the sFLASH commissioning results will be discussed.

Slides TUZA02 [4.125 MB]

TUODB03

Innovative Design of the Fast Switching Power Supplies for the SOLEIL EMPHU Insertion and its Fast Correctors

power-supply, controls, simulation, permanent-magnet

982

F. Bouvet, D. Aballea, R. Ben El Fekih, S. Bobault, M. Bol, Y. Bouanani, Y. Dietrich, A. Hardy, F. Marteau
SOLEIL, Gif-sur-Yvette, France

A new electromagnetic/permanent magnets helical undulator has been designed and is under commissioning at SOLEIL. For a fast switching of the photon polarization, it requires a power supply able to switch between +/350 A within 50 ms, without any current overshoot and with a very good current resolution over the full scale (50 ppm). The in-house design is based on two full switching bridges with interleaved commands. Combined with a regulation scheme using sophisticated algorithms, such a design enables to reach a high control bandwidth, permitting fast transitions. Such a fast and accurate system needs well performing digital control electronics. We chose the digital control cards developed at Paul Scherrer Institute (Villigen CH) for the SLS (Swiss Light Source). The components, measurements, interlocks, control interfaces, and electronic cards were developed and assembled together at SOLEIL. This paper will present the main lines of this development and the performances achieved during the EMPHU insertion commissioning. The design of the fast power supplies (±20 A) needed for corrector magnets of this insertion will also be presented.

Slides TUODB03 [3.017 MB]

TUPC006

Production of Highly Polarized Positron Beams*

polarization, positron, photon, target

997

A. Ushakov, O.S. Adeyemi, V.S. Kovalenko, L.I. Malysheva, G.A. Moortgat-Pick
University of Hamburg, Hamburg, Germany
A.F. Hartin
DESY, Hamburg, Germany
S. Riemann, A. Schälicke, F. Staufenbiel
DESY Zeuthen, Zeuthen, Germany

Funding: This work is supported by the German Federal Ministry of Education and Research, Joint Research Project R&D Accelerator "Spin Management", contract number 05H10GUE
Using of polarized electron and positron beams significantly increases the physics potential of future linear colliders. The generation of an intense and highly polarized positron beam is a challenge. The undulator-based positron source located at the end of electron linac is the baseline source for the International Linear Collider. In case of a 250 GeV drive beam energy, an helical undulator with K = 0.92, an undulator period of 11.5 mm and a titanium alloy target of 0.4 radiation length thickness, the average polarization of the generated positrons is relatively low (about 22 percent). In this contribution, the possibilities of increasing the positron polarization have been considered by adjusting the undulator field and selecting those photons and positrons that yield a highly polarized beam. The detailed simulations have been performed with our developed Geant4-based application PPS-Sim*.
* http://pps-sim.desy.de

TUPC069

Bunch Length Measurements from the Incoherent Synchrotron Radiation Fluctuation at SOLEIL

radiation, optics, electron, photon

1159

M.-A. Tordeux, F. Dohou, M. Labat, O. Marcouillé
SOLEIL, Gif-sur-Yvette, France

Bunch length measurements can be made by analysing the pulse to pulse intensity fluctuation of the incoherent synchrotron radiation as it has been reported elsewhere*. Such a method has been tested at SOLEIL for picosecond bunch durations, at several wavelengths and bandwidths in the visible range, using an avalanche photodiode. Thanks to the low-alpha optics the lengths of 10 μA bunches as short as 3 ps have been measured in good agreement with the streak camera results. We first used the radiation from a bending magnet, and then from a HU640 undulator that enhances the photon flux. Moreover, taking advantage of using the radiation from an undulator, we show that the method can still be used when the number of spikes emitted by the electron bunch is reduced to a few hundreds. This could be of interest for bunch length measurements of X-ray SASE FELs. Furthermore, we intend to use a single crystal diamond detector in order to perform these measurements in the X-ray range.
* F. Sannibale et al., "Absolute bunch length measurements by incoherent radiation fluctuation analysis", PRST AB 12, 032801 (2009).

TUPC091

Operational Results of the Diamond-based Halo Monitor during Commissioning of SPring-8 XFEL (SACLA)

electron, laser, wakefield, scattering

1218

H. Aoyagi
JASRI/SPring-8, Hyogo-ken, Japan
Y. Asano, H. Kitamura, T. Tanaka
RIKEN/SPring-8, Hyogo, Japan

Funding: This work is partly supported by Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (c) 21604017.
Measurement of electron beam halo is very important issue for X-ray free electron laser and synchrotron radiation facilities, because the beam halo may cause radiation damage of undulator magnets. Furthermore, it may cause degradation in quality of electron beam, and radio activation of beam ducts and components. In order to prevent these situations, a diamond-based halo monitor (HM) has been developed for the SPring-8 Angstrom Compact free electron LAser (SACLA). We have achieved excellent detection limit of 0.3 fC/pulse for single-shot measurement, which corresponds to the ratio of 10^-6 to the beam core. The commissioning of the HM, which was installed at the upstream of 90m undulator, has been carried out, and it has been figured out that the intensity of the beam halo can be measured very nicely since secondary electrons and bremsstrahlung that are emitted in the accelerator components have not been observed. We also describe systematic profile measurements of the beam halo and operational results of the HM during the commissioning of SACLA.

TUPC160

Recent Developments of Diagnostics at Diamond

photon, feedback, synchrotron, diagnostics

1407

G. Rehm, C. Bloomer, A.F.D. Morgan, C.A. Thomas
Diamond, Oxfordshire, United Kingdom

This contribution summarizes some recent development of diagnostics system to improve the operation of Diamond Light Source. Firstly, we are advancing the integration of photon beam diagnostics with the orbit feedback system. Measurements have shown the correlation between recorded electron and photon beam motion on the short timescales (ms-minutes) and the potential for improvement on long timescales (minutes-days). Secondly, with the addition of more elliptically polarized undulators at Diamond, measurement of their photon beam position require a solution that reliably operates with the changing photon beam profiles emitted by these devices. To this end, we have developed an X-ray beam position monitor that analyzes the backscatter from an aperture in the front end. Thirdly, as operation in low-alpha mode with few ps bunch lengths receives increasing interest from users, we have been evaluating various techniques for the measurement of these short bunch lengths that could serve as alternatives to streak camera measurements.

TUPO004

Generation of Attosecond Soft X-ray Pulses in a Longitudinal Space Charge Amplifier

electron, space-charge, laser, radiation

1449

M. Dohlus, E. Schneidmiller, M.V. Yurkov
DESY, Hamburg, Germany

A longitudinal space charge amplifier (LSCA), operating in soft x-ray regime, was recently proposed. Such an amplifier consists of a few amplification cascades (focusing channel and chicane) and a short radiator undulator in the end. Broadband nature of LSCA supports generation of few-cycle pulses as well as wavelength compression. In this paper we consider an application of these properties of LSCA for generation of attosecond x-ray pulses. It is shown that a compact and cheap addition to the soft x-ray free electron laser facility FLASH would allow to generate 60 attosecond (FWHM) long x-ray pulses with the peak power at 100 MW level and a contrast above 98%.

TUPO005

Design Optimization for a Non-Planar Undulator for the JETI-Laser Wakefield Accelerator in Jena

electron, laser, radiation, wakefield

1452

V. Afonso Rodriguez, T. Baumbach, A. Bernhard, G. Fuchert, A. Keilmann, P. Peiffer, C. Widmann
KIT, Karlsruhe, Germany
M. Kaluza, M. Nicolai
IOQ, Jena, Germany
R. Rossmanith
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

In a laser wakefield accelerator (LWFA), excited by a femtosecond laser pulse electrons are accelerated to several 100 MeV within a few centimeters. The energy spread of the electron beam is relatively large and varies from shot to shot. In order to obtain monochromatic photons in an undulator despite the energy spread, the following idea was proposed. Two bending magnets and a drift space in between produces dispersion so that particles with different energies have different transverse positions. The beam enters a non-planar undulator, e.g. cylindrical pole geometry, where the K-value also varies with transverse position. If the two variations in the transverse direction (particle energy and K-value) compensate each other the generated light is more monochromatic than with a conventional planar undulator. In this paper such a modified undulator design optimized for the JETI-LWFA in Jena is presented. An experiment to test this concept is in preparation.

TUPO006

Design of a Dispersive Beam Transport Line for the JETI Laser Wakefield Accelerators

radiation, electron, dipole, quadrupole

1455

C. Widmann, V. Afonso Rodriguez, T. Baumbach, A. Bernhard, P. Peiffer
KIT, Karlsruhe, Germany
M. Kaluza, M. Nicolai
IOQ, Jena, Germany
R. Rossmanith
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

Laser wakeﬁeld accelerators (LWFA) emit electrons with energies of a few 100 MeV at very short bunch lengths while having a compact design. However, electron bunches from LWFA show a larger energy spread than those of conventional accelerators. This is a challenge when using these bunches e.g. to generate radiation in an undulator. A possible strategy to cope with that is to spectrally disperse the bunch and match the resulting spatial distribution with a spatially varying undulator ﬁeld amplitude. For realizing the dispersion a pair of dipole magnets is used. The electrons leaving this dipole chicane have to meet certain requirements imposed by the undulator: In the deﬂection plane the beam has to be collimated and its energy distribution must match the undulator ﬁeld. In the other transversal plane the beam has to be focussed on the center of the undulator keeping the value of the beta function small. To include this in the compact design of the setup, a combination of specially designed quadrupole and sextupole magnets is employed. In this contribution the design of the setup and the results of the particle tracking through this chicane are presented.

TUPO017

Peculiarities of the Excitation of an Optical Resonator by an Electron Beam

electron, radiation, damping, storage-ring

1479

E.G. Bessonov, M.V. Gorbunkov, A.L. Osipov
LPI, Moscow, Russia
A.A. Mikhailichenko
CLASSE, Ithaca, New York, USA

The peculiarities of the optical resonator excitation by electrons in a FEL based on the Self-Stimulated Undulator Radiation at main and collateral synchronicity conditions are discussed*.
* E.G.Bessonov et al., Self-Stimulated Undulator Radiation and its Possible Applications, http://arxiv.org/ftp/arxiv/papers/10⁰⁹/1009.3724.pdf

TUPO018

Self-stimulated Undulator Klystron

FEL, electron, kicker, storage-ring

1482

E.G. Bessonov, A.L. Osipov
LPI, Moscow, Russia
A.A. Mikhailichenko
CLASSE, Ithaca, New York, USA

The Self Stimulated Undulator Klystron (SSUK) and its possible applications in the Particle Accelerator Physics, incoherent Self-Stimulated Undulator Radiation Sources (SSUR) and Free-Electron Lasers are discussed*.
* E.G.Bessonov et al., Self-Stimulated Undulator Radiation and its Possible Applications: http://arxiv.org/ftp/arxiv/papers/10⁰⁹/1009.3724.pdf

TUPS012

The Present Status of Vacuum System of XFEL in SPring-8

vacuum, shielding, electron, laser

1542

T. Bizen
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
T. Hasegawa
RIKEN/SPring-8, Hyogo, Japan

The vacuum component assembly and installation were completed by February in 2011. The total length of the vacuum system is about 630 m. A 455 sputter ion pumps and a 10⁸ NEG cartridge pumps generate vacuum. The average pressures are on the order of ·10^-7 Pa or less. The flange developed for C-band waveguide shows high reliability of vacuum seal.

WEXA01

Challenges of 4th Generation Light Sources

FEL, electron, emittance, photon

3798

C. Pellegrini
SLAC, Menlo Park, California, USA
C. Pellegrini
UCLA, Los Angeles, California, USA

In the last few years Free Electron Lasers (FELs) have emerged as exceptionally exciting tools for new science. The results from FLASH (Hamburg) on biological imaging, LCLS (Stanford) which generated the first hard X-ray lasing and the projects proposed or in costruction around the world are rapidly moving the scientific community to the so called “fast science” which demands ultrashort pulses, fs synchronization, high brightness, high coherence X-rays. The basic SASE FEL process used so far converts energy jitter into jitter of the centralwavelength. Processes based on seeding and HGHG seem to offer a number of advantages in terms of bandwidth, coherence, stability and undulator length. This talk will present an overview of the 4th generation light sources, discussing the main challenges afforded in the construction of the operating facilities and considering the trends for the development of future facilities.

Slides WEXA01 [10.640 MB]

WEOBB02

Bunch Length Diagnostic with Sub-femtosecond Resolution for High Brightness Electron Beams

laser, electron, simulation, cavity

1967

G. Andonian, E. Hemsing, P. Musumeci, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
A.Y. Murokh
RadiaBeam, Santa Monica, USA
D. Xiang
SLAC, Menlo Park, California, USA

Next generation light sources require electron beams with high peak currents, typically achieved by compression techniques. The temporal diagnosis of these ultra-short beams demands enhanced resolution. We describe a scheme to achieve a temporal resolution on the order of sub-femtoseconds. The scheme is based on encoding the longitudinal profile of the beam on a transverse angular modulation, based on an interaction between the electron beam and a high-power laser in an undulator. This imposes a fast-sweep of the beam, on the order of sub-femtoseconds. A subsequent sweep in the orthogonal dimension by an rf deflecting cavity, imposes a "slow-sweep" on the order of sub-picoseconds. In this paper, we demonstrate applicability of this diagnostic scheme at the BNL ATF and specify the techniques required for practical applicability.

Slides WEOBB02 [1.120 MB]

WEPC008

Optics for the Beam Switchyard at the European XFEL

kicker, septum, quadrupole, extraction

2016

N. Golubeva, V. Balandin, W. Decking
DESY, Hamburg, Germany

The European XFEL is planed as a multi-user facility with the possibility to distribute electron bunches of one beam pulse to different beamlines. The initial stage foresees two electron beamlines each serving its own set of undulators. The later addition of a third beamline is also considered in the design of the distribution system. In addition, the integration of the transport line to the beam abortion dump allows a flexible selection of the bunch repetition pattern for each beamline. The beam extraction, both in undulator beamlines and in the beamline to the dump, will be realized with fast kickers and a Lambertson septum. In this paper we describe the magnet lattice of the deflection arcs with simultaneous horizontal and vertical dispersions and the beam optics of the beam switchyard.

WEPC050

New Optics for the SOLEIL Storage Ring

optics, injection, coupling, vacuum

2124

P. Brunelle, F. Briquez, A. Loulergue, O. Marcouillé, A. Nadji, L.S. Nadolski, M.-A. Tordeux, J.F. Zhang
SOLEIL, Gif-sur-Yvette, France

SOLEIL, the French 2.75GeV synchrotron light source is delivering photons to 24 beam lines and is presently equipped with 22 insertion devices (ID) including a high field and small gap in-vacuum wiggler*. This paper presents the continuous work performed to reduce the strong non linear effects of several IDs. On one side, the ID defaults have been precisely identified using on-beam measurements, and magnetic correction developments are going on, especially for the in-vacuum wiggler and for the 10m long HU640 undulator. On the other side, a new optics has been optimised in terms of beta-functions (at the ID location) and non linear dynamics in order to improve the injection efficiency and the beam lifetime in the presence of IDs. The modified optics has been used daily in operation since November 2010 and ensures a beam lifetime greater than 10h for a 400mA stored beam with the users ID configuration. In parallel, an extensive experimental optimization has been performed to prepare the operation with an additional quadrupole triplet that provides double low vertical beta functions in one long straight section that will accommodate two canted in-vacuum insertion devices**.
* O. Marcouillé et al., IPAC10, p. 3102 (2010).
** A. Loulergue et al., IPAC10, p. 2496 (2010).

WEPC072

Insertion Devices and Beam Dynamics in the PLS-II Storage Ring

wiggler, betatron, insertion, insertion-device

2187

S. Chunjarean, S. Shin
PAL, Pohang, Kyungbuk, Republic of Korea

Effects of insertion devices like a superconducting multipole wiggler or an in-vacuum undulator on the beam dynamics of tghe upgraded Pohang Light Source (PLS-II) storage ring have been investigated. The narrow gap related to a short period length of the in-vacuum undulator or a transverse magnetic field roll off can impact the dynamic aperture or Touschek lifetime or injection efficiency. A three dimensional magnetic field model has been developed based on numerical data consisting of several coefficients in the Taylor expansion to accurately represent the actual field. In this paper, the magnetic field model has been produced with the differential algebraic code COSY INFINITY to formulate the Taylor transfer map for the wiggler and undulator. Frequency map analysis (FMA) and full 6D tracking has been performed to investigate resonances which may affect the particle stability and causing a reduction in injection efficiency.

WEPC137

Undulator Radiation Simulation by QUINDI

radiation, electron, simulation, polarization

2316

D. Schiller, E. Hemsing, J.B. Rosenzweig
UCLA, Los Angeles, California, USA

QUINDI, a code developed to simulate coherent emission from bending systems, has been upgraded to include undulators as a beamline element. This approach allows us to better model the radiation produced by a relativistic electron bunch propagating through such a device.

WEPC163

A New Embedded Radiation Monitor System for Dosimetry at the European XFEL

radiation, neutron, controls, linac

2364

F. Schmidt-Föhre, D. Nölle, R. Susen, K. Wittenburg
DESY, Hamburg, Germany
L. Fröhlich
ELETTRA, Basovizza, Italy

The upcoming European XFEL will be built at a length of approx. 3.4 km between the campus of the Deutsches Elektronen-Synchrotron DESY at Hamburg and Schenefeld at Schleswig-Holstein for commissioning in 2015. The XFEL utilizes various electronic systems for machine control, diagnostics and safety. To achieve a cheap and compact accelerator construction, the beam pipe and its nearby electronic supply systems are located inside the same tunnel, charged by an evident amount of radiation in certain sections of the XFEL. To insure the lifecycle and function of electronics and magnetic structures like undulators in these XFEL radiation fields, all electronic systems located inside the tunnel will be sufficiently shielded according to pre-estimated radiation levels. In addition, these electronics and the undulator parts will be monitored for the impact of Gamma- and Neutron-radiation by a new versatile and compact radiation monitor system. It measures the accumulated dose in the electronic cabinets along the XFEL to ensure an exchange of radiated parts before significant radiation damage occurs. First prototype measurements at different radiation sources will be presented.

WEPC164

First Operation of a Fiber Beam Loss Monitor at the SACLA FEL

beam-losses, vacuum, electron, radiation

2367

X.-M. Maréchal, T. Itoga
JASRI/SPring-8, Sayo-gun, Japan
Y. Asano
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

A fiber-based Cerenkov beam loss monitor (CBLM) has been developed as a quick and long-range detection tool for radiation safety at the X-ray FEL SACLA (SPring-8 angstrom compact free electron laser) to minimize electron beam losses. Based on tests carried out at the 250 MeV SPring-8 Compact SASE Source facility, large core (400 μm), long (>120 m) multimode fibers were selected and installed in the undulator section of SACLA. We report on the first few months of operation of the CBLM. During the commissioning of the X-FEL, the CBLM has performed effectively, with a detection limit below 10 pC per pulse across the 110 meters of the in-vacuum undulators, and with a position accuracy of less than 2 m. Experimental results are presented along with detailed numerical studies including the geometry of in-vacuum insertion devices, and discussed.

WEPC169

BPM System Interlock for Machine Protection at SOLEIL

photon, vacuum, power-supply, electron

2379

J.-C. Denard, C. Herbeaux, M. Labat, V. Leroux, A. Loulergue, J.L. Marlats
SOLEIL, Gif-sur-Yvette, France

SOLEIL, a third generation light source, has its Beam Position Monitors (BPM) processed by the LIBERA electronics built by Instrumentation Technologies. This electronics initiated and specified by SOLEIL features a fast hardware interlock output for machine protection. Although interlocks are available in both horizontal and vertical planes, it was initially thought that only the vertical interlocks would be useful. Actually, the high photon beam power densities (up to 1kW/mm2) generated by the in-vacuum undulators could damage vacuum chamber elements in case of corrector power supply failures in horizontal or vertical plane. Crotch absorbers, XBPMs and their upstream absorbers were designed on the basis that they will be protected with interlock thresholds not tighter than ±1mm. This approach was also applied for specifying the apertures of the XBPMs and of their upstream absorbers. More recently tracking simulation has shown that the crotch absorber apertures downstream the new canted undulators needed special attention.

THPC009

Performance and Upgrade of the ESRF Light Source

emittance, cavity, storage-ring, vacuum

2924

J.-L. Revol, J.C. Biasci, J-F. B. Bouteille, J. Chavanne, F. Ewald, L. Farvacque, A. Franchi, G. Gautier, L. Goirand, M. Hahn, L. Hardy, J. Jacob, J.M. Koch, M.L. Langlois, G. Lebec, J.M. Mercier, T.P. Perron, E. Plouviez, K.B. Scheidt, V. Serrière
ESRF, Grenoble, France

The European Synchrotron Radiation Facility (ESRF) is now fully engaged in a large Upgrade Programme of its infrastructure, beamlines and X ray source. In this context, a first set of 10 insertion device straight sections are being lengthened from five to six metres; a number of them will be operated with canted undulators. The insertion devices are themselves subject to an ambitious development programme to fulfil the scientific requirements. The Radio Frequency system upgrade has started with the replacement of the booster klystron-based transmitter by high power solid state amplifiers, and the development of HOM damped cavities operating at room temperature. A completely new DC-AC orbit stabilization system using 224 BPMs and 96 orbit steerers is currently being commissioned. The upgrade is conducted while keeping, and even improving, routine performance for the user service. In particular the recent installation of new skew quadrupole power supplies allows routine operation with ultra low vertical emittance. This paper reports on the present operation performance of the source, highlighting recent developments and those still to come.

THPC012

Mitigating the Pertubations Caused by U 180 at the Metrology Light Source

dipole, quadrupole, optics, focusing

2930

P.O. Schmid, D.B. Engel, J. Feikes, M. Ries, G. Wüstefeld
HZB, Berlin, Germany

The Metrology Light Source is equipped with an electromagnetic undulator with a period length of 180 mm. User requests demand operation of this undulator in a wide energy range from 100 MeV through 629 MeV for user and dedicated low alpha modes. Mitigating the pertubations caused by the undulator to an acceptable level for all user requests, requires each quadrupole in the lattice to be powered individually. To what extend this recently implemented capability allows the restoration of the main properties of the machine optics for various settings of the undulator is presented in this document.

THPC015

A Dedicated THz Beamline at DELTA

laser, electron, radiation, simulation

2939

M. Höner, M. Bakr, H. Huck, S. Khan, R. Molo, A. Nowaczyk, A. Schick, P. Ungelenk, M. Zeinalzadeh
DELTA, Dortmund, Germany

Funding: Work supported by DFG, BMBF, and by the Federal State NRW
As a consequence of the new radiation source for ultrashort VUV pulses at DELTA, which is based on the interaction of electrons with fs laser pulses, coherent THz radiation is emitted. Simulations of the laser-electron interaction, particle dynamics and radiation spectrum, as well as the optical and mechanical design of a dedicated THz beamline are presented. First experimental results including laser-electron overlap diagnostics and characterization of the THz radiation are discussed.

THPC016

Ultrashort VUV and THz Pulse Generation at the DELTA Storage Ring

laser, electron, radiation, klystron

2942

A. Schick, M. Bakr, H. Huck, M. Höner, S. Khan, R. Molo, A. Nowaczyk, P. Ungelenk, M. Zeinalzadeh
DELTA, Dortmund, Germany

Funding: Supported by DFG, BMBF, and the Federal State NRW
The optical klystron (two undulators, separated by a dispersive section) at DELTA, formerly operated as storage-ring FEL, is seeded with ultrashort pulses from a Ti:Sapphire laser. The thus induced energy modulation of an electron bunch in the first undulator is converted to a density modulation within the dispersive chicane. In the second undulator, the micro-bunched electrons emit ultrashort pulses coherently at harmonics of the fundamental laser wavelength. Additionally, coherent ultrashort THz pulses are generated several meters downstream of the optical klystron by the laser-induced gap in the electron bunch. First results are presented.

THPC017

Temporal and Spatial Alignment of Electron Bunches and Ultrashort Laser Pulses for the CHG Experiment at DELTA

laser, electron, controls, synchrotron

2945

M. Zeinalzadeh, M. Bakr, H. Huck, M. Höner, S. Khan, R. Molo, A. Nowaczyk, A. Schick, P. Ungelenk
DELTA, Dortmund, Germany

Funding: Supported by DFG, BMBF, and the Federal State NRW
The generation of ultrashort VUV pulses by CHG (Coherent Harmonic Generation) requires achieving and maintaining the longitudinal and transversal overlap of femtosecond laser pulses and electron bunches. We present the techniques and the experimental setup applied at the DELTA storage ring. For the longitudinal analysis, both a streak camera and a fast photo diode are used. Transversely, two CCD cameras acquire images of laser and synchrotron light at different positions inside of the undulator. A feedback system utilizes the intensity of a THz signal generated several meters downstream of the undulator to optimize and maintain the overlap.

THPC020

PETRA III Upgrade

sextupole, optics, focusing, single-bunch

2948

K. Balewski, M. Bieler, J. Keil, A. Kling, G.K. Sahoo, R. Wanzenberg
DESY, Hamburg, Germany

PETRA III, the new third generation light source at DESY, has been running as a user facility since middle of 2010. All 14 undulator beam lines have been commissioned and up to 12 of them are currently in operation. However, already during the planning phase of PETRA III it turned out that the number of beamlines will not be sufficient to fulfill the request for beam time. The pressure to add more beamlines to PETRA III even increased after the decision to shut down DORIS III at the end of 2012. To increase the number of experimental stations two additional halls will be built each housing 5 additional beam lines and about 100 m of the accelerator close to each of the new buildings will be completely remodeled to install additional undulators. The upgrade has been formally approved and at present should be accomplished during a 6 month shut down in 2013. In this paper the layout of the upgraded accelerator will be shown. The impact of the upgrade on machine performance has been studied both theoretically and experimentally and the results of these studies will be presented.

THPC029

Ultra-low Emittance Light Source Storage Ring Consisting of 5-Bend Achromat Cells with Four Long Straight Sections

lattice, emittance, storage-ring, wiggler

2972

K. Tsumaki
JASRI/SPring-8, Hyogo-ken, Japan

The 6 GeV ultimate storage ring (USR) consisting of ten bend achromat cells has been proposed* and applied it to the SPring-8 Storage ring**. It has the same circumference as the SPring-8 storage ring, but does not have four long straight sections, where the SPring-8 storage ring does. The cell length is twice of that of the SPring-8 storage ring and the number of cell is half of the SPring-8. The photon beam line positions would deviate from those of the existing one. To avoid these problems, we designed a storage ring that has four long straight sections and same cell number. The cell is changed from ten bend achromat to five bend achromat and the cell length is shortened to 30 m which is the same length of the SPring-8 storage ring unit cell. The total ring consists of 44 five bend achromat cells and four long straight section cells. The emittance is 10⁴ pm and it will reduce to less than 50 pm by radiation damping of wigglers and undulators. The brightness is expected to be more than 10²2 phs/s/mm²/mrad² in 0.1%BW with 200 mA beam current.
* K. Tsumaki, N. Kumagai, NIM A 565 (2006) 394.
** K. Tsumaki, N. Kumagai, Proc. of EPAC06, THPLS035, p. 3362 (2006).

THPC040

Expected Performance Characteristic of Accelerator-based THz Source at Tohoku University

radiation, electron, focusing, gun

2990

H. Hama, F. Hinode, S. Kashiwagi, M. Kawai, X. Li, T. Muto, K. Nanbu, Y. Tanaka
Tohoku University, School of Science, Sendai, Japan
N.Y. Huang
NTHU, Hsinchu, Taiwan

Funding: This work is supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research (S), Contract #20226003.
Sources of coherent synchrotron radiation at THz wavelength region have been constructed at Tohoku University. Bunch train of extremely shorter electron pulse less than 100 fs will be provided by an injector linac employing thermionic rf gun, where the bunch compression will be performed by means of velocity bunching in an accelerator structure. Radiation source under development are a Halbach type planar undulator and an accumulator isochronous ring. The undulator employs large gap and long period length configuration, so that the resonant frequency of 1 THz is achieved when a lower beam energy of ~ 20 MeV. Since spectrum of coherent synchrotron radiation (CSR) is strongly depending on longitudinal bunch form factor, we have calculated CSR spectra for various conditions of the beam to evaluate the performance of the THz source. Numerical simulation with multi-particle system has been carried out to understand the radiation power and angular distribution as well. The beam transport in the undulator is crucial for quality of the radiation because the beam energy is very much low relative to strong focusing power. Characteristics of THz CSR from the undulator will be discussed.

THPC042

Status and Development of the SAGA Light Source

storage-ring, laser, controls, linac

2996

T. Kaneyasu, Y. Iwasaki, S. Koda, Y. Takabayashi
SAGA, Tosu, Japan

The SAGA Light Source (SAGA-LS) is a synchrotron radiation facility consisting of a 255 MeV injector linac and a 1.4 GeV storage ring, and has been stably providing synchrotron light since 2006. The annual failure time is less than 1% of the user time in the recent two years. Three insertion devices are installed in the storage ring: an APPLE-II undulator, a planar type undulator (Saga Univ.) and a 4 T superconducting wiggler (SCW). The SCW contains a hybrid three-pole magnet; the main pole of the magnet is surrounded by superconducting coils while side poles are normal conducting magnets. The main pole of the SCW is cooled by a GM cryocooler, which allows the SCW be operated without liquid helium. Since the installation in March 2010, the SCW has been operated stably. To control the ID parameters during the user time, a feed-forward correction system which minimizes the ID effects on the emittance coupling was developed. The laser Compton Gamma-rays were generated by using a CO2 laser and were used for beam energy measurement. In addition, research works on the beam lifetime and interaction between electron beam and crystal, and development of a multipole magnet are in progress.

THPC044

Operation and Performance Upgrade of the Soleil Storage Ring

vacuum, storage-ring, photon, feedback

3002

A. Nadji, P. Brunelle, M.-E. Couprie, J.-C. Denard, J.-M. Filhol, J.-F. Lamarre, P. Lebasque, A. Loulergue, P. Marchand, L.S. Nadolski, R. Nagaoka, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette, France

SOLEIL delivers photons to 24 beamlines. Up to 22 very diverse insertion devices (IDs) are now installed on the storage ring, and 4 more will come by summer 2011, including a Cryogenic undulator and an electromagnetic/permanent magnet helical undulator, both designed and built at SOLEIL. Work is continuing on beam dynamics and magnetic corrections to reduce the nonlinear effects of all these IDs. A new optics incorporating an additional quadrupole triplet in one long straight section has been successfully tested and will be put in operation by fall 2011. A new coupling correction will also be implemented to maintain the ratio of the vertical to the horizontal emittances at 1% for any IDs configuration. The electron beam orbit stability has been significantly improved reaching a residual noise of 300 nm RMS. Photon LIBERA modules of X-BPM located on the bends, will be integrated soon in the orbit feedback loops. 4905 hours have been delivered in 2010 to the beamlines with an availability of 96.3%. The user operation with the maximum current of 500 mA is foreseen to start by fall 2011, after the completion of the radiation safety tests of the beamlines.

THPC055

Front Ends at ALBA

vacuum, photon, radiation, synchrotron

3017

J. Marcos, J. Campmany, D. Einfeld, J. Pasquaud
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

ALBA is a 3GeV 3rd generation synchrotron radiation source built nearby Barcelona currently under commissioning phase. This paper describes the design and installation of the set of 10 Front Ends that have been manufactured and assembled for day-one operation of the facility. This initial set includes 8 Front Ends devoted to transmit the photons generated by both Insertion Device or Bending Magnet sources to experimental Beamlines, and 2 additional Front Ends for electron beam-diagnostics purposes. The design of each individual Front End has been adapted in order to meet the aperture and power load requirements posed by both the characteristics of the photon sources and the needs of the Beamline users. At the same time, an effort has been made in order to keep a suitable degree of standardization among the components of different Front Ends. With this aim a modular design approach has been adopted. The general layout of the Front Ends as well as the design and function of their main components is described. Finally, a brief summary of their performance during the commissioning period is presented.

THPC079

Echo-enabled Harmonic Generation at DELTA

laser, electron, bunching, storage-ring

3074

R. Molo, M. Bakr, H. Huck, M. Höner, S. Khan, A. Nowaczyk, A. Schick, P. Ungelenk, M. Zeinalzadeh
DELTA, Dortmund, Germany

Funding: Supported by DFG, BMBF, and the Federal State NRW
We present conceptual studies of the realization of the echo-enabled harmonic generation (EEHG) technique proposed by G. Stupakov* as an upgrade of the present coherent harmonic generation (CHG) project at the DELTA storage ring**. EEHG allows to reach shorter wavelengths compared to the CHG scheme. In addition to the optical klystron used for CHG, a third undulator is needed for a second energy modulation of the electron bunch, followed by an additional strong dispersive section. Installing these insertion devices requires a new long straight section in the storage ring and a new lattice configuration.
* G. Stupakov Phys. Rev. Lett. 10², 074801 (2009)
** A. Schick et al., this conference

THPC081

Status of the Free-Electron Laser FLASH at DESY

FEL, photon, laser, radiation

3080

M. Vogt, B. Faatz, J. Feldhaus, K. Honkavaara, S. Schreiber, R. Treusch
DESY, Hamburg, Germany

The free-electron laser facility FLASH at DESY, Germany has been upgraded in 2010. Now, FLASH delivers an electron beam energy up to 1.25 GeV. The longitudinal phase-space is linearized by 3.9 GHz superconducting cavities. The facility delivers to users ultra-short laser like radiation pulses in the range of less than 50 fs to 200 fs in the soft X-ray wavelenth range from 44 down to 4.1 nm. FLASH provides hundreds to thousands pulses per second to users with unprecedented peak brilliance. FLASH will be upgraded with a second undulator beam line and an additional experimental hall. Construction starts Autumn 2011. We summarize the operational status of the ongoing 3rd user period.

THPC082

Properties of the Radiation from the European X-ray Free Electron Laser

electron, FEL, radiation, emittance

3083

E. Schneidmiller, M.V. Yurkov
DESY, Hamburg, Germany

Recent success of the Linac Coherent Light Source (LCLS) demonstrated feasibility for reliable production, compression, and acceleration of electron beams with emittances significantly smaller than original baseline parameters. The same scenario can be applied to the European XFEL as well. Experimental results from the Photo Injector Test Facility in Zeuthen (PITZ) demonstrated the possibility to generate electron beams with small charge and emittance. Computer modeling of the beam formation system also indicate on the possibility to preserve electron beam quality during acceleration and compression. Recently these trends have been analyzed, and baseline parameters of the European XFEL have been revised. Parameter space has been significantly extended in terms of the bunch charge. As a result, different modes of FEL operation become possible with essentially different properties of the radiation. In this paper we present an overview of radiation properties of SASE FEL radiators driven by electron beam with new baseline parameters.

THPC083

Analysis of Parameter Space of a Kilowatt-scale Free Electron Laser for Extreme Ultraviolet Lithography Driven by L-band Superconducting Linear Accelerator Operating in a Burst Mode

electron, radiation, FEL, laser

3086

E. Schneidmiller, V. Vogel, H. Weise, M.V. Yurkov
DESY, Hamburg, Germany

The driving engine of the Free Electron Laser in Hamburg (FLASH) is an L-band superconducting accelerator. It is designed to operate in a burst mode with 800 microsecond pulse duration at a repetition rate of 10 Hz. The maximum accelerated beam current during the macropulse is 10 mA. In this paper we analyze the parameter space for optimum operation of the FEL at the wavelength of 13.5 nm and 6.7 nm. Our analysis shows that the FLASH technology holds great potential for increasing the average power of the linear accelerator and an increase of the conversion efficiency of the electron kinetic energy to the light. Thus, it will be possible to construct a FLASH like free electron laser with an average power up to 3 kW. Such a source meets the requirements of the light source for the next generation lithography.

THPC084

Optical Afterburner for a SASE FEL: First Results from FLASH

electron, radiation, FEL, resonance

3089

M. Foerst
CFEL, Hamburg, Germany
M. Gensch
HZDR, Dresden, Germany
R. Riedel, E. Schneidmiller, N. Stojanovic, F. Tavella, M.V. Yurkov
DESY, Hamburg, Germany

Radiation Pulse from a Self-Amplified Spontaneous Emission Free Electron Laser (SASE FEL) consists out of spikes (wavepackets). Energy loss in the electron beam (averaged over radiation wavelength) also exhibits spiky behaviour on a typical scale of coherence length, and follows the radiation pulse envelope. These modulations of the electron beam energy are converted into large density (current) modulations on the same temporal scale with the help of a dispersion section, installed behind the x-ray undulator. Powerful optical radiation is then generated with the help of a dedicated radiator (afterburner). Envelope of the optical afterburner pulse is closely resembles the envelope of the x-ray pulse. We have recently demonstrated this principle at the Free Electron Laser in Hamburg (FLASH). We use THz undulator that is installed after the main X-ray as both dispersive element and radiator simultaneously. We characterize properties of the optical pulse using standard laser diagnostics techniques (i.e. FROG). Main result comes from the pulse duration measurement that we use to derive envelope of the x-ray radiation pulse duration which is in sub-100 fs range.

THPC086

Status Report on FERMI@Elettra Project

FEL, photon, linac, electron

3095

F. Parmigiani, M. Svandrlik, D. Zangrando
ELETTRA, Basovizza, Italy

Funding: This work was supported in part by the Italian Ministry of University and Research under grants FIRB-RBAP045JF2 and FIRB-RBAP06AWK3
FERMI@Elettra, a single-pass FEL user-facility covering the wavelength range from 100 nm (12 eV) to 3 nm (413 eV) located next to the third-generation synchrotron radiation facility Elettra in Trieste, Italy is actually under completion and will start user operation next year. The first seeded lasing was observed in December 2010 and the first experiments have started this year. In this paper an overview of the present status of machine and beamlines systems will be given as well as a status about operation and future upgrade.

THPC089

Study of a Modified Quasi-periodic Undulator

radiation, photon, electron, insertion

3104

A.L. Wu, Q.K. Jia
USTC/NSRL, Hefei, Anhui, People's Republic of China

To suppress high-order harmonic radiation effectively while maintain comparatively higher fundamental radiation intensity, a modified quasi-periodic undulator (QPU) which the magnet blocks have different size is studied in this paper. Then the paper also compares the radiation spectrum of various structural schemes. It is shown that the higher harmonic radiation of this new scheme will be suppressed more effectively than the conventional QPU.

THPC096

Soft X-ray Free-electron Laser with a 10-time Reduced Size

electron, FEL, bunching, laser

3113

Y.-C. Huang, F.H. Chao, C.H. Chen, K.Y. Huang
NTHU, Hsinchu, Taiwan
P.J. Chou
NSRRC, Hsinchu, Taiwan

Funding: This work is supported by National Science Council under Contract NSC 99-2112-M-007 -013 -MY3.
We present a 30-m long soft x-ray FEL consisting of a 5-MeV photoinjector, a 150 MeV linac, a magnetic chicane compressor, and a 3-m long undulator. We employ both the 3rd and the 4th harmoincs of a Nd laser at 355 and 266 nm, respectively, to illuminate the cathode of the photoinjector. Owing to the beating of the two lasers, the emitted electron beam is modulated at 282 THz. The electrons are further accelerated to 150 MeV and, after acceleration, compressed by 33 times in a magnetic chicane. The temporal compression of the electron macropulse increases the electron bunching frequency to 9.3 PHz, corresponding to a soft x-ray wavelength of 32.2 nm. We adopt a solenoid-derived staggered array undulator* with a 3-m length, 5 mm undulator period, and 1.2 mm gap. With a solenoid field of 10 kG, we estimate an undulator parameter of 0.4 and a corresponding radiation wavelength of 32.2 nm for a 150 MeV driving beam. With 3.3-kA peak current, 0.03% energy spread, 2 mm-mrad emittance, and 80-micron beam radius at the undulator entrance, the GENESIS code predicts 0.2 GW radiation power from the 3-m long undulator for an initial bunching factor of merely 10 ppm.
* Y.C. Huang, H.C. Wang, R.H. Pantell, and J. Feinstein, "A staggered-array wiggler for far infrared, free-electron laser operation," IEEE J. Quantum Electronics 30 (1994) 1289.

THPC097

Transverse Alignment Tolerances for the European XFEL Laser Heater

laser, electron, FEL, emittance

3116

V.A. Goryashko
NASU/IRE, Kharkov, Ukraine
M. Dohlus
DESY, Hamburg, Germany
M. Hamberg, V.G. Ziemann
Uppsala University, Uppsala, Sweden

Funding: Supported by the KTH-SU-UU FEL Center.
We study the impact of misalignments between a laser beam and an electron bunch on the energy distribution function of the electron bunch in the laser heater. Transverse position and angular misalignment as well as different spot size of the laser and electron beam are considered. We find that the transverse misalignment makes the energy distribution function narrower compared to the case of ideal adjustment and a distinct peak in the distribution around the initial mean value of the energy appears. We demonstrate that despite these misalignments a uniform heating in terms of the energy spread can be achieved by appropriately adapting the transverse size and power of the laser beam such that the energy distribution function of the electron bunch at the end of the laser heater can be made similar to a Gaussian, thus providing more effective Landau damping against the micro-bunching instability. The laser power mainly determines the local energy spread while the laser spot size governs the shape of the energy distribution function. The transverse oscillations of electrons induced by the magnetic field in the laser heater are found to be non-essential for typical operation parameters.

THPC100

Full Temporal Reconstruction using an Advanced Longitudinal Diagnostic at the SPARC FEL

FEL, diagnostics, radiation, laser

3119

G. Marcus, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
M. Artioli, F. Ciocci, L. Giannessi, A. Petralia, M. Quattromini, V. Surrenti
ENEA C.R. Frascati, Frascati (Roma), Italy
A. Bacci, M. Bellaveglia, E. Chiadroni, G. Di Pirro, M. Ferrario, G. Gatti, A. Mostacci, A.R. Rossi
INFN/LNF, Frascati (Roma), Italy
A. Cianchi
INFN-Roma II, Roma, Italy
V. Petrillo
Istituto Nazionale di Fisica Nucleare, Milano, Italy
J.V. Rau
ISM-CNR, Rome, Italy

The Production of ultra-short (sub 100 fs) single-spike radiation possessing full longitudinal coherence from a free-electron laser (FEL) has been the subject of intense study. A Frequency-Resolved Optical Gating (FROG) diagnostic has been developed and tested at UCLA, which has the capability of providing a longitudinal reconstruction of these ultra-fast pulses. This paper reports the results of the application of the diagnostic at the SPARC FEL facility.

THPC101

Fitting Formulas for Space-charge Dominated Free-electron Lasers

FEL, space-charge, electron, simulation

3122

G. Marcus, E. Hemsing, J.B. Rosenzweig
UCLA, Los Angeles, California, USA

A simple power-fit formula for calculating the gain length of the fundamental Gaussian mode of a free-electron laser having strong space-charge effects in the 3D regime has been obtained. This tool allows for quick evaluation of the free-electron laser performance in the presence of diffraction, uncorrelated energy spread, and longitudinal space-charge effects. Here, we use it to evaluate the performance of high-gain FEL amplifiers considered candidates as high average power light sources. Results are compared with detailed numerical particle simulations using the free-electron laser code Genesis.

THPC104

Optimization for Single-Spike X-Ray Fels at LCLS with a Low Charge Beam

laser, FEL, simulation, electron

3131

L. Wang, Y.T. Ding, Z. Huang
SLAC, Menlo Park, California, USA

The recently commissioned Linac Coherent Light Source is an x-ray free-electron laser at the SLAC National Accelerator Laboratory, which is now operating at x-ray wavelengths of 20-1.2 Angstrom with peak brightness nearly ten orders of magnitude beyond conventional synchrotron sources. At the low charge operation mode (20 pC), the x-ray pulse length can be <10 fs. In this paper we report our numerical optimization and simulations to produce even shorter x-ray pulses by optimizing the machine and undulator setup. In the soft x-ray regime, with the help of slotted-foil or undulator taper, a single spike x-ray pulse is achievable with peak FEL power of 30 GW.

THPC106

Commissioning Status of the Fritz Haber Institute THz FEL

electron, FEL, linac, gun

3137

A.M.M. Todd, H. Bluem, V. Christina, M.D. Cole, J. Ditta, D. Dowell, K. Jordan, R. Lange, J.H. Park, J. Rathke, T. Schultheiss, L.M. Young
AES, Princeton, New Jersey, USA
W. Erlebach, S. Gewinner, H. Junkes, A. Liedke, G. Meijer, W. Schöllkopf, G. von Helden
FHI, Berlin, Germany
S.C. Gottschalk
STI, Washington, USA

The THz Free-Electron Laser (FEL) at the Fritz Haber Institute (FHI) of the Max Planck Society in Berlin is designed to deliver radiation from 3 to 300 microns using a single-plane-focusing mid-IR undulator and a two-plane-focusing far-IR undulator that acts as a waveguide for the optical mode. A key aspect of the accelerator performance is the low longitudinal emittance, < 50 keV-psec, that is specified to be delivered at 200 pC bunch charge and 50 MeV from a gridded thermionic electron source. We utilize twin accelerating structures separated by a chicane to deliver the required performance over the < 20 - 50 MeV energy range. The first structure operates at near fixed field while the second structure controls the output energy, which, under some conditions, requires running in a decelerating mode. "First Light" is targeted for the centennial of the sponsor in October 2011 and we will describe progress in the commissioning of this device to achieve this goal. Specifically, the measured performance of the accelerated electron beam will be compared to design simulations and the observed matching of the beam to the mid-IR wiggler will be described.

THPC149

Development of PrFeB Cryogenic Undulator (CPMU) at SOLEIL

cryogenics, vacuum, permanent-magnet, storage-ring

3233

C. Benabderrahmane, P. Berteaud, N. Béchu, L. Chapuis, M.-E. Couprie, J.P. Daguerre, J.-M. Filhol, C. Herbeaux, A. Lestrade, M. Louvet, J.L. Marlats, K. Tavakoli, M. Valléau, D. Zerbib
SOLEIL, Gif-sur-Yvette, France

A R&D programme for the construction of a 2 m long 18 mm period CPMU is under progress at SOLEIL. The cryogenic undulator will provide photons in the region of 1.4 to 30 keV. It will be installed in the next few months on the long straight section (SDL13) of the storage ring, and could be used later on to produce photons for the NANOSCOPIUM beamline. The use of PrFeB which features a 1.35 T remanence (Br) at room temperature enables to increase the peak magnetic field at 5.5 mm minimum gap, from 1.04 T at room temperature to 1.15 T at a cryogenic temperature of 77 K. Praseodymium was chosen instead of Neodymium magnetic material, because it is more resistant against the appearance of the Spin Reorientation Transition. Different corrections were performed first at room temperature to adjust the phase error, the electron trajectory and to reduce the multipolar components. The mounting inside the vacuum chamber enables the fitting of a dedicated magnetic measurement bench to check the magnetic performance of the undulator at low temperature. The results of the magnetic measurements at low temperature and the comparison with the measurement at room temperature are reported.

THPC150

Review of Insertion Device Dedicated to HIgh Energy Photons at SOLEIL

vacuum, photon, brightness, insertion

3236

O. Marcouillé, C. Benabderrahmane, P. Berteaud, F. Briquez, L. Chapuis, M.-E. Couprie, T.K. El Ajjouri, F. Marteau, M. Valléau, J. Vétéran
SOLEIL, Gif-sur-Yvette, France

Producing high energy photons between 10 keV and 70 keV is a challenging topic in a medium energy storage ring. It requires up-to-date measurement techniques and specific Insertion Device (ID) technologies to produce high magnetic fields and short periods. SOLEIL (2.75 GeV) has designed and built eight conventional in-vacuum hybrid undulators operating at high radiation harmonics and also one small gap multipole wiggler to produce high magnetic field. The construction has been progressively improved by the choice of new magnetic materials of better quality and higher magnetization, additional correction techniques and mechanical changes. A 2-m long full scale cryogenic undulator made of PrFeB and vanadium permendur has been built, measured, corrected and is to be tested on the beam. An additional wiggler dedicated for Slicing experiments has been designed. The required magnetic field is high enough to also consider the ID as a good candidate for the production of hard X-ray photons. This paper presents the ID dedicated for the high energy photons and their spectral performances.

THPC151

The 65 mm Period Electromagnetic/Permanent Magnets Helical Undulator at SOLEIL

permanent-magnet, power-supply, electron, wiggler

3239

F. Marteau, P. Berteaud, F. Bouvet, L. Chapuis, M.-E. Couprie, J.P. Daguerre, T.K. El Ajjouri, J.-M. Filhol, P. Lebasque, J.L. Marlats, A. Mary, K. Tavakoli
SOLEIL, Gif-sur-Yvette, France

SOLEIL prepares a new 65 mm period Electromagnetic/Permanent Magnets Helical Undulator (EMPHU), with a rapid switching at 5 Hz of the polarization required for dichroïsm experiments. The vertical field Bz is produced by coils fed by a fast switching power supply (designed and built in house), with a maximum current of 350 A and a polarity switching time shorter than 100 ms. The coils consist of 25 stacked copper layers shaped by water jet cutting. The current flows in 16 layers and 9 of them are cooled with thermal drain to a water piping. 4 additional power supplies feed 2 types of correction coils for the dynamic compensation of the field integrals, besides the ones for the termination. 1.28 T remanence NdFeB permanent magnets generate the horizontal field Bx. Peak Bz and Bx in the helical configuration reach 0.24 T at 14.7 mm minimum gap. Thermal modelling and measurements aim at keeping the magnet temperature constant. The static magnetic configuration was optimised using the ID_Builder software and the trajectory were checked for insuring a good reproducibility of the photon beam pointing when sweeping from one helicity to the other.

THPC152

Measurements of SOLEIL Insertion Devices using Pulsed Wire Method

insertion, insertion-device, wiggler, vacuum

3242

M. Valléau, C. Benabderrahmane, M.-E. Couprie, O. Marcouillé, F. Marteau, J. Vétéran
SOLEIL, Gif-sur-Yvette, France

SOLEIL permanent magnets insertion devices are usually measured with a Hall probe in order to evaluate the electron angular deflexion, their deviation and the optical phase error, a figure of merit related to the quality of the insertion device radiation. A pulsed wire bench is developed at SOLEIL for reducing the measurement time of an undulator and for providing a measurement method without lateral access. A current pulse injected in a stretched wire inside the magnetic field area generates acoustic wave. The wire motion is detected by optical sensors whose signals are proportional to the local integral value. The signal-to-noise ratio of this method is often reduced due to several effects such as electronic noise, external and wire vibrations. However, following some hardware optimization it was possible to increase it up to almost 26 dB, making the method accurate and reproducible in order to realize efficient corrections. Measurements of first and second integral performed with Pulse wire, with Hall probe and with the electron beam are compared on three different types of insertions: an U18 in-vacuum cryogenic undulator, a HU60 APPLE-II undulator and a WSV50 in-vacuum wiggler.

THPC153

Recent Progress in Insertion Devices at the ESRF

multipole, insertion, insertion-device, quadrupole

3245

J. Chavanne, G. Lebec, C. Penel, F. Revol
ESRF, Grenoble, France

Insertion Device activities at the ESRF are presently driven by the upgrade of more than ten beamlines. The concept of canted undulators is part of the requirements in a number of cases. Permanent Magnet Steerers (PMS) will be used to create canting angles of up to 5.4 mrad. The magnetic structure of PMS has been fully optimized to minimise space occupancy and magnetic perturbations induced on neighbouring undulators. The measured field quality of PMS recently constructed will be presented. The development of undulators dedicated to high photon energy is still being pursued. Following on from the successful operation since 2008 of a first Cryogenic Permanent Magnet Undulator (CPMU) installed in the ID6 beamline, a second device has been constructed. This 2 m long device has a period of 18 mm and will be operated at 145 K. The field measurements at cryogenic temperature are discussed hereafter.

THPC154

Shimming of the Dynamic Field Integrals of the BESSY II U125 Hybrid Undulator

wiggler, permanent-magnet, electron, injection

3248

J. Bahrdt, W. Frentrup, A. Gaupp, M. Scheer, I. Schneider, G. Wüstefeld
HZB, Berlin, Germany

Within a continuous program the BESSY II undulators are prepared for Topping-Up operation. The BESSY II U125 planar hybrid undulator has a period length of 125 mm and a pole width of only 60 mm. The horizontal defocusing of the 1.7 GeV e-beam may result in a significant reduction of the horizontal dynamic aperture, reducing the injection efficiency when injecting into the closed gap. The dynamic field integrals are derived from a 2D-Fourier decomposition of the 3D-field. An analytic description of the dynamic multipoles based on the Fourier coefficients is presented. Magic fingers have been installed in order to minimize the dynamic field integrals and to enlarge the good field region of the device.

THPC155

Modification of the BESSY II Optic for the Implementation of a Small Gap Undulator

optics, cryogenics, quadrupole, sextupole

3251

J. Bahrdt, K.B. Bürkmann-Gehrlein, V. Dürr, W. Frentrup, A. Gaupp, A. Jankowiak, P. Kuske, J. Rahn, M. Scheer, P.O. Schmid, G. Wüstefeld
HZB, Berlin, Germany

At BESSY there is an increasing demand for photons in the range from 60 eV to 8 keV available at the same experimental station. The photons will be produced by a combination of two adjacent undulators, one of them will be a small period cryogenic undulator. Several optics schemes for the 1.7 GeV BESSY II storage ring are discussed to install the undulators. Two types of straight sections exist. A high beta straight with betax_min=15 m and betay_min=4.5 m and a low beta straight with betax_min=betay_min=1 m. We discuss the present plan, which clearly favours a small detuning of an existing low beta straight to shift the low beta waist to the centre of the low gap undulator, with only minor impact to the machine.

THPC156

Performance of the PETRA III APPLE II Undulator

multipole, storage-ring, closed-orbit, optics

3254

J. Bahrdt, W. Frentrup, A. Gaupp, M. Scheer
HZB, Berlin, Germany
K. Balewski, J. Keil, A. Schöps, M. Tischer
DESY, Hamburg, Germany

A 5m-long APPLE II undulator has been built in collaboration between Helmholtz-Zentrum Berlin and DESY Hamburg. Magnetic field measurements after the final shimming in the laboratory are presented. The device has been installed in the storage ring and machine studies have been performed. The tune shifts in the elliptical and the inclined mode are in agreement with predictions from theory. The dynamic field integrals have successfully been minimized in the storage ring with so-called L-shims (rectangular iron sheets) which are placed at the undulator center at the magnet edges.

THPC157

Hot-/Cold-Side Characterization of Asymmetric Undulator Magnets

permanent-magnet, magnet-design, induction, insertion

3257

F.-J. Börgermann
Vacuumschmelze GmbH & Co. KG, Hanau, Germany
S. Marks
LBNL, Berkeley, California, USA

The homogeneity of permanent magnets for use in undulators is dominantly described by small variations in remanence (±1%) and magnetic angles (±1°). The definition and measurement of the so-called hot-/cold-side-effect has proven to be useful as characterization of higher order variations of the local field components. It is measured by a Hall probe at a distance of the half gap width from both magnet pole-surfaces. Typical results for a batch of magnets lie in a range of about ±2% or less. For symmetrical permanent magnet geometries, the distribution is symmetric about the value of zero. In a batch of magnets for a new EPU at LBNL, however, we found an asymmetric distribution of the hot-/cold-side-effect. This asymmetry is attributed to the geometrically asymmetric cut-outs inside the magnets used for fixture on the aluminum keepers. We present a theoretical model which can predict this asymmetric influence on the hot-/cold-side-effect resulting from these small geometric asymmetries. The method may also be used to pre-calculate corrected specification values for the near-field results for future undulator magnets.

THPC158

Field Optimization for Short Period Undulators

wiggler, permanent-magnet, insertion, damping

3260

P. Peiffer, A. Bernhard
KIT, Karlsruhe, Germany
R. Rossmanith
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
D. Schoerling
CERN, Geneva, Switzerland

Undulators dedicated to low energy electron beams, like Laser Wakefield Accelerators, require very short period lengths to achieve X-ray emission. However, at these short period lengths (~5 mm) it becomes difficult to reach magnetic field amplitudes that lead to a K parameter of ~1, which is generally desired. Room temperature permanent magnets and even superconductive undulators using Nb-Ti as conductor material have proven insufficient to achieve the desired field amplitudes. The superconductor Nb3Sn has the theoretical potential to achieve the desired fields. However, up to now it is limited by several technological challenges to much lower field values than theoretically predicted. Alternatives for higher fields would be to manufacture the poles of the undulator body from Holmium instead of iron or to use Nb-Ti wires with a higher superconductor/copper ratio. The advantages and challenges of the different options are compared in this contribution.

THPC160

A Superconducting Switch for Insertion Devices with Variable Period Length

insertion, insertion-device, power-supply, wiggler

3266

T. Holubek, T. Baumbach, S. Casalbuoni, S. Gerstl, A.W. Grau, M. Hagelstein, D. Saez de Jauregui
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
C. Boffo, W. Walter
BNG, Würzburg, Germany

Superconducting insertion devices (IDs) are very attractive for synchrotron light sources since they offer the possibility to enhance the tuning range and functionality significantly by period length switching. Period length switching can be realized by employing two or more individually powerable subsets of superconducting coils and by reversing the current in a part of the winding. So far, the first demonstration mock-up coil allowing period length tripling was fabricated and tested successfully. Here, we report on the feasibility of a superconducting switch operating at 4.2 K, immersed in a liquid Helium bath as well as under conduction cooled conditions.

THPC161

Possible Superconducting Insertion Devices with Period Length Doubling for Beamlines of Third Generation Light Sources

simulation, insertion, insertion-device, photon

3269

D. Saez de Jauregui, T. Baumbach, S. Casalbuoni, S. Gerstl, A.W. Grau, M. Hagelstein, T. Holubek
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

The tunability of an insertion device can be increased by period length switching, which in superconducting insertion devices (IDs) can be achieved by reversing the current in separately powered subsets of the superconducting windings. The feasibility of this concept has been experimentally proven. We study here different possibilities to tailor the needs of beamlines of third generation light sources: FEM simulations performed to compute the magnetic field on axis of such devices with different period lengths are reported together with the spectral simulations.

THPC162

Possible Application of NbTi Wire with Artificial Pinning Centres for Insertion Devices

brilliance, insertion, insertion-device, vacuum

3272

T. Holubek, S. Casalbuoni, S. Gerstl, A.W. Grau, D. Saez de Jauregui
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
M. Klaeser, T. Schneider
FZ Karlsruhe, Karlsruhe, Germany
L. Motowidlo
SupraMagnetics, Inc., Plantsville, USA

Superconductive insertion devices (IDs) allow higher fields for a given gap and period length compared to the classical permanent magnet IDs. This technological concept permits to increase the brilliance and/or the photon energy. The working horse for superconducting magnets are multifilament NbTi wires, which are nowadays also used for superconducting insertion devices. Even higher magnetic fields can be reached by using a conductor with enhanced critical current density. Here, we propose a possible application for superconducting undulators, wound with NbTi wire with artificial pinning centres, developed by SupraMagnetics, Inc. We report the critical current characteristic, Jc(B), of short wire measured in a liquid helium bath, and the load-line of a racetrack coil, designed to simulate the field configuration on the conductor as in a superconducting undulator. Based on the measured load-line we report the simulations of the magnetic field on axis and of the spectrum in a third generation light source of a possible undulator wound with a wire having similar properties of the measured one.

THPC163

Local and Integral Field Measurement Setup for 2m Long Superconducting Undulator Coils

factory, synchrotron, insertion, insertion-device

3275

A.W. Grau, T. Baumbach, S. Casalbuoni, S. Gerstl, M. Hagelstein, T. Holubek, D. Saez de Jauregui
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

The performance of superconducting insertion devices depends strongly on their magnetic field quality. It is of fundamental importance to characterize the magnetic properties of insertion devices accurately before installation in synchrotron light sources. Thus a main part of the R&D program for superconducting insertion devices at the Karlsruhe Institute of Technology focuses on quality assessment. This contribution describes the instrumentation to perform magnetic measurements of the local field, of the field integrals and of the multipole components of superconducting undulator coils in a cold in vacuum (cryogen free) environment. It focuses on the outcome of the factory acceptance test together with results of first field measurements performed with mock-up coils.

THPC164

Phase Shifters for the FERMI@Elettra Undulators

electron, FEL, radiation, polarization

3278

B. Diviacco, R. Bracco, D. Millo, M.M. Musardo
ELETTRA, Basovizza, Italy

The variable gap undulator system in operation at the FERMI@Elettra Free Electron Laser facility requires adjustable phase matching devices between consecutive radiator segments in order to maintain optimal lasing conditions while changing the radiation properties. A permanent magnet phase shifter has been designed to achieve the required electron beam delay in a compact structure that could be installed in close proximity to the undulators. In this paper we present the design of the phasing units and the results of the magnetic measurements performed on the five devices installed so far. We also describe the method used to properly set their field strength for any given electron energy, radiation wavelength and polarization.

THPC165

Estimations for Demagnetization of ID Permanent Magnets due to Installation of OTR

electron, permanent-magnet, radiation, simulation

3281

Y. Asano
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
T. Bizen
JASRI/SPring-8, Hyogo, Japan

Demagnetization due to high energy electron irradiation is one of the crucial issues for stable operation of X-ray free electron laser (XFEL) and Synchrotron radiation (SR) facilities. Especially, during the commissioning, electron beam is scattered and then hits permanent magnets of insertion devices due to installation of some instrumentations such as OTR (Optical Transition Radiation) for beam diagnosis so that the estimation of demagnetization is very important to perform the commissioning smoothly. Fortunately, we found the index of demagnetization of Nd2Fe14B permanent magnets due to high energy electron irradiation. Star density produced by high energy photo-neutron reproduces experimental results of demagnetization. At SPring-8, in-vacuum type undulators have been employed for XFEL so that we estimate the demagnetization of the undulators for various cases such as electron energy in ranging from 2 GeV to 8 GeV and the permanent magnet gap from 2 mm to 40 mm. And we also estimate the allowable time to be able to insert the OTR.

THPC166

Design Consideration of New Insertion Devices of Hefei Light Source

vacuum, photon, radiation, insertion

3284

Q.K. Jia
USTC/NSRL, Hefei, Anhui, People's Republic of China

To meet the requirements of users for higher brilliance and good transverse coherence VUV and soft X-ray synchrotron radiation, Hefei Light Source(HLS) will be upgraded. After upgrade HLS will have smaller beam emittance and install more insertion devices. In this paper the design considerations of new insertion devices are reported, they include one elliptically polarizing undulator, one quasi-periodic undulator, one in-vacuum undulator and one wiggler.

THPC167

The Design of Dual Canted In-vacuum Undulators at SSRF

vacuum, radiation, ion, synchrotron

3287

X. Hu, L. Yin, Q.G. Zhou
SINAP, Shanghai, People's Republic of China

Funding: National foundation for scientific infrastructure, Development and Reform Commission of China.
Five new beamlines are under design and construction at SSRF to supply the synchrotron radiation for the structural biology research in the protein project. Two in-vacuum undulators with canted angle of 6mrad are arranged in a 6.5m long straight section in order to keep the potential to accommodate more beamlines for the future. Limited by the length of the straight section and the angle between two beamlines, the layout design in the straight section is rather difficult to satisfy the required photon flux to the beamline and keep the normal design of the undulator. Many main components will be redesigned in this section on the base of existing ones, including in-vacuum undulator, correction magnet, RF bellows, photon absorbers and so on. In this paper the layout design and the modified design for some key components are described.

THPC168

Field Error Correction for a Superconducting Undulator

photon, radiation, electron, simulation

3290

S. Chunjarean
PAL, Pohang, Kyungbuk, Republic of Korea
C.-S. Hwang, J.C. Jan
NSRRC, Hsinchu, Taiwan
H. Wiedemann
SLAC, Menlo Park, California, USA

To reach higher photon energies in the region of soft or hard x-rays with high photon beam brightness in low energy storage rings, superconducting undulators with very short period length and high magnetic field strength are required. Because undulator radiation comes in a line spectrum, photons up to the 7th harmonic are desired. The photon brightness in such harmonics is strongly dependent on perfect periodicity of the magnetic field. Such imperfections also appear in conventional permanent material undulators, which can be corrected by well developed and efficient shimming. Unfortunately, this method cannot be applied to superconducting undulators. Therefore, we present a new approach to field corrections by modification of the magnetic field saturation in each pole. In this paper it is shown that this approach can reduce not only the magnetic field error but also greatly improves phase errors from period to period. The proposed method works quite local with only small perturbations in neighboring poles. The tenability is preserved for most of the field excitations and is reduced only at extreme parameters.

THPC169

Short-Period RF Undulator for a Nanometer SASE Source

electron, cavity, injection, radiation

3293

S.V. Kuzikov, M.E. Plotkin, A.A. Vikharev
IAP/RAS, Nizhny Novgorod, Russia
J.L. Hirshfield
Yale University, Physics Department, New Haven, CT, USA
T.C. Marshall, G.V. Sotnikov
Omega-P, Inc., New Haven, Connecticut, USA

Funding: Sponsored in part by US Department of Energy, Office of High Energy Physics.
A room-temperature RF undulator to produce ~1 nm wavelength radiation using a relatively low energy electron beam (0.5 GeV) is considered. The design features include an effective undulator period of 0.45 cm, an undulator parameter of K = 0.4, an effective field length of 50 cm. These parameters could be be realized using a multi-MW RF power amplifier to drive the undulator (e.g., the 34 GHz pulsed magnicon at Yale or a 30 GHz gyroklystron at IAP) with microsecond pulse duration. Two undulator designs were considered that avoid problems with a co-propagating wave: a dual-mode cylindrical cavity [TE01 (counter propagating) - TE02 (co-propagating)] with an off-axis electron beam; and a traveling HE11 mode resonant ring with an on-axis beam.

THPC170

Magnetic Characterization of FEL-2 Undulators for the FERMI@Elettra Free-electron Laser

FEL, multipole, sextupole, quadrupole

3296

M. Kokole
KYTE, Sezana, Slovenia
B. Diviacco
ELETTRA, Basovizza, Italy
T. Milharcic, M. Zambelli
KYMA, Trieste, Italy
G. Soregaroli, M. Tedeschi
Euromisure srl, Pieve S. Giacomo (Cremona), Italy

Kyma Srl is the spin-off company of Sincrotrone Trieste, Elettra laboratory, set up in 2007 together with the two industrial partners Cosylab d.d. and Euromisure SpA, in order to design and manufacture the undulators for the FERMI@Elettra project in Trieste, Italy. The insertion devices, for FEL-2 line, manufactured and characterized so far are the following: Modulator, 3.2 m linearly polarized undulator, three 55.2 mm APPLE-II variable polarization undulators, each 2.4 m long and six 34.8 mm APPLE-II undulators also each 2.4 m long. All the above devices have been characterized, both from the mechanical and the magnetic point of view. The measured parameters are in good agreement with the design values. This paper presents the most relevant changes in design from FEL-1 to FEL-2 line and results of the magnetic measurements carried out on all the above undulators.

THPC171

Performance of ID at ALBA

vacuum, wiggler, storage-ring, insertion

3299

J. Campmany, J. Marcos, V. Massana
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

The new synchrotron light source ALBA is currently being commissioned along with the first phase of beamlines. Up to 6 beamlines are using light produced by Insertion Devices. There are up to four types of IDs: 2 Apple-II undulators (EU62 and EU71) operating at low energies, one conventional wiggler (MPW80) operating in the range of 2 – 20 keV, two in-vacuum undulators (IVU21) operating in the range 5 – 30 keV and a superconducting wiggler (SCW30) operating in the range of 40 keV. Installation of the IDs has been done in two steps. First, the out-vacuum devices (EU62, EU71 and MPW80) have been mechanically installed. Initial commissioning of Storage Ring has been done with their gaps opened to maximum value. Then, their gap has been closed to study the effect in the beam dynamics. In the second step, the in-vacuum devices (both IVU21 and the SCW30) have been installed and tested. In this paper we present the first results and performances of the insertion devices obtained both in Site Acceptance Test and during the first months of commissioning with beam.

THPC173

Modelization of Inhomogeneities in Permanent Magnet Blocks

permanent-magnet, insertion, insertion-device, simulation

3305

V. Massana, J. Campmany, J. Marcos
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

Nowadays one of the main objectives for insertion devices manufacturers is to reduce the gap of undulators as much as possible while keeping the features of the generated magnetic field. Because of that, the effects of magnetic blocks’ inhomogeneities are playing an increasing role in the quality of the whole device. In this paper we present a modelization of the inhomogeneities of permanent magnet blocks used to build wigglers and undulators. The model is based in splitting individual magnet blocks in different parts which are considered magnetically homogeneous. The model takes into account the relative orientation of magnet blocks assembled into their holders as well as local magnetic properties. We have applied the model to fit magnetic field integrals measured with a fixed stretched wire bench and magnetization data obtained from Helmholtz coils measurements for both single blocks and groups of blocks mounted on a common holder. The results of the model fit with experimental data within an rms error of 6•10^-4 mT•m for individual blocks and 1.5•10^-4 mT•m in the case of magnet groups.

THPC174

Manufacturing and Testing of the First Phase Shifter Prototypes Built by CIEMAT for the European-XFEL

controls, electron, free-electron-laser, laser

3308

I. Moya, J. Calero, J.M. Cela-Ruiz, L. García-Tabarés, A. Guirao, J.L. Gutiérrez, L.M. Martinez Fresno, T. Martínez de Alvaro, E. Molina Marinas, A.L. Pardillo, L. Sanchez, S. Sanz, F. Toral, C. Vazquez, J.G.S. de la Gama
CIEMAT, Madrid, Spain

Funding: Work partially supported by the Spanish Ministry of Science and Innovation under SEI Resolution on 17-September-2009.
The European X-ray Free Electron Laser (EXFEL) will be based on a 10 to 17.5 GeV electron linac. Its beam will be used in three undulator systems to obtain ultra-brilliant X-ray flashes from 0.1 to 6 nanometres for experimentation. The undulator systems are formed by 5m long undulator segments and 1.1m long intersections in between. They accommodate a quadrupole on top of a precision mover, a beam position monitor, two air coil correctors and a phase shifter. The function of the phase shifter is to adjust the phase of the electron beam with respect to that of the radiation field when the wavelength is changed by tuning the gap. In this context, CIEMAT will deliver 92 phase shifters, as part of the Spanish in-kind contribution to the EXFEL project. This paper describes the engineering design, the manufacturing techniques and the mechanical and magnetic tests realized on the first prototypes.

THPC175

Spectral Analysis of Arbitrary Strength Parameter for Various Insertion Devices

photon, wiggler, insertion, insertion-device

3311

S.D. Chen, T.M. Uen
NCTU, Hsinchu, Taiwan
C.-S. Hwang
NSRRC, Hsinchu, Taiwan

An insertion device (ID) with medium strength parameter was hard to be defined as a wiggler or an undulator. Usually, this kind of ID was classified according to the user’s definition and to select the spectrum calculation formula of wiggler or undulator. The spectrum calculation formula for wiggler or undulator is quite difference and consequently obtain a big different flux density by using the same strength parameter. So, it is no way that the spectrum calculation of them is consistent. Therefore, a universal formula will be developed for the spectrum analysis for the different kinds of insertion devices that is with large different strength parameter (deflection parameter). Consequently, a modified spectrum calculation formula of ID with medium strength parameter was studied by reviewing the difference of existing spectrum formulas. The familiar formula of calculating undulator spectrum was modified and can be used on ID with arbitrary strength parameter. The algorithm of formula modification was described. Some relative issue, like the effect of phase error and energy spread, and taper undulator were also discussed herein.

THPC176

Progress in Insertion Devices for TPS in Phase I

insertion, insertion-device, photon, vacuum

3314

C.H. Chang, C.-H. Chang, J.C. Huang, C.-S. Hwang, C.K. Yang
NSRRC, Hsinchu, Taiwan

Taiwan Photon Source (TPS) with beam energy 3 GeV and beam current 500 mA is a third-generation synchrotron radiation facility of medium energy. In the initial commissioning stage of TPS, the machine will be equipped with ten insertion devices (ID) and serve seven beamlines in phase I. Of these, three long straight sections configured as a double-minimum betay function lattice design with minimized beam influence of emittance are used for the installation of a pair of insertion devices in a straight section, two undulators of APPLE-II type and four in-vacuum undulators (IU), to produce great brilliance and coherent X-rays with great flux. The details of these insertion devices are explained herein.

THPC177

Field Correction Results from NSRRC Elliptically Polarized Undulator 46

kicker, electron, multipole, synchrotron

3317

J.C. Huang, C.-H. Chang, C.-S. Hwang, C. JunTune, F.-Y. Lin
NSRRC, Hsinchu, Taiwan

Elliptically polarized undulator (EPU) is a common insertion device to use in storage ring in order to provide circular polarization. The field correction is an essential step for EPU construction, and it can prevent the photon flux reduction from idea case and electron beam trajectory and exit angle from EPU. The conventional field correction method is tedious works and strongly based on experiences. An initial state of NSRRC EPU46 has phase error over 40 degrees, and many difficulties on field correction to reduce the phase error under 5 degrees. This paper will describe the detailed magnetic field correction process and practical results from in NSRRC EPU.

THPC178

Superconducting Planar Undulator Development in the UK

cryogenics, cryomodule, vacuum, radiation

3320

J.A. Clarke, D.J. Scott, B.J.A. Shepherd
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
V. Bayliss, T.W. Bradshaw, A.J. Brummitt, G.W. Burton, M.J.D. Courthold, M.J. Hills, S.R. Watson, M.L. Woodward
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

Superconducting undulators promise higher peak fields on axis than any other technology but they are still not a mainstream solution for 3rd or 4th generation light sources. A team within the UK is developing the design of a short period, narrow aperture, superconducting undulator that is planned to be installed and tested in the Diamond Light Source (DLS) in 2014. This paper will describe the main parameters of the undulator and the key design choices that have been made. Recent progress is then described in the areas of magnet modelling, mechanical design, cryogenic design, and prototyping. Finally, the next steps are described.

THPC179

Electron Beam Heating and Operation of the Cryogenic Undulator and Superconducting Wigglers at Diamond

electron, wiggler, cavity, synchrotron

3323

J.C. Schouten, E.C.M. Rial
Diamond, Oxfordshire, United Kingdom

Diamond Light Source has two superconducting wigglers and one cryocooled undulator installed serving three beam lines. The cryocooled undulator (cpmu) has been operating since August 2010 while the superconducting wigglers have been operating for more than 4 years (SCW-1) and 2 years (SCW-2). We will report on the first year of operation of the cpmu including details of its spectral output and cryogenic performance. Our experience of the cooling system and measures taken to ensure reliability and to minimize the risks of a prolonged downtime are also presented. The two superconducting wigglers are exposed to a high heat load due to the beam heating of the inner liner. Until recently this resulted in a much higher helium consumption than specified and so recently a new liner has been fitted to SCW-1 and new re-condensers to SCW-2. In addition a thermal bridge has been made between the RF tapers and the outer heat shield of both SCW-1 and SCW-2. The results of these improvements will be presented.

THPC183

Application of the Balanced Hybrid Mode in Overmoded Corrugated Waveguides to Short Wavelength Dynamic Undulators

cavity, impedance, FEL, electron

3326

S.G. Tantawi, G.B. Bowden, C. Chang, J. Neilson, M. Shumail
SLAC, Menlo Park, California, USA
C. Pellegrini
UCLA, Los Angeles, California, USA

Funding: Work Supported by the US Department of Energy
Inspired by recent developments in low-loss overmoded components and systems for ultra-high power RF systems, we explored several overmoded waveguide systems that could function as RF undulators. One promising structure is a corrugated waveguide system operating at the hybrid HE11 mode. This is a new application for that mode. Initial calculations indicate that such a system can be operated at relatively low power levels while obtaining large values for the undulator parameters. RF surface fields are typically low enough to permit superconducting operation. This technology could realize an undulator with short wavelengths and also dynamic control of the undulator parameters including polarization. We introduce the scaling laws governing such a structures, and then show with exact simulations an undulator design that have a wavelength of about 1.4 cm with an undulator parameter K~1. This undulator is intended to be powered by a 50 MW source at a frequency of 11.4 GHz. We describe the experimental setup for testing such a technology.

THPC184

Progress of the Coherent Soft X Ray Straight Section at NSLS-II

electron, photon, polarization, insertion

3329

C.A. Kitegi, P. Cappadoro, O.V. Chubar, T.M. Corwin, D.A. Harder, P. He, Y. Li, C. Meyer, G. Rakowsky, J. Rank, C. Rhein, C.J. Spataro, T. Tanabe
BNL, Upton, Long Island, New York, USA

The National Synchrotron Light Source II (NSLS-II) is the new light source under construction at Brookhaven National Laboratory (BNL). The Coherent Soft X rays beam line (CSX) is one of the six beamlines included in the baseline project. Following the request of CSX scientists for a source providing adjustable polarized radiation from 160 eV to 1.7 keV, two Advanced Planar Polarized Light Emitter II (APPLE-II)-type undulators will be installed in a 6.6 m long straight section. Each device is 2 m long, the period is 49.2 mm and the minimum gap is 11.5 mm. The different operation modes of the beamline and the layout of the straight section are reviewed here.

THPC186

Heat Load for the APS Superconducting Undulator

photon, radiation, simulation, shielding

3332

L.E. Boon, A.F. Garfinkel
Purdue University, West Lafayette, Indiana, USA
K.C. Harkay
ANL, Argonne, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The APS Upgrade calls for the development and commissioning of a superconducting undulator (SCU) at the Advanced Photon Source (APS), a 7-GeV electron synchrotron. The first SCU will be installed in June 2012. Until then, simulations such as SYNRAD3D will be used to understand and reduce the heat load on the cryo-system from primary and secondary photons. Current calculations predict that primary photons will distribute 0.5W/m on the chamber walls of the cryostat. SYNRAD3D will be used to calculate the ratio of primary and secondary photons to calculate the heat load due to secondary photons. Previous simulations were of only one sector of the APS accelerator. Simulated here are multiple sectors, to include photons back scattered from downstream photon absorbers.