• G. LeBlanc
  ASCo, Clayton, Victoria

The Australian Synchrotron has been running normal operations for beamlines since April 2007. The high degree of beam availability has allowed for an extensive accelerator physics program to be developed. The main points of this program will be presented, including student involvement at different levels and developments being made in anticipation of moving to top-up mode injections.

• D. Morris, G. LeBlanc, D.C. McGilvery, J. Trewhella
  ASCo, Clayton, Victoria

The Australian Synchrotron has been open to users since April 2007. Beam availability is now consistently above 98%, with a Mean Time Between Failures (MTBF) of approximately 50 hours and a Mean Down Time (MDT) of approximately 1 hour. This paper discusses the program of activities that has been undertaken to improve beam availability, and to maximize the MTBF and reduce the MDT.

• T.K. Charles
  Monash University, Faculty of Science, Victoria
• M.J. Boland, R.T. Dowd, M.J. Spencer, Y.E. Tan
  ASCo, Clayton, Victoria

The Australian Synchrotron booster synchrotron accelerates electrons from 100 MeV to 3 GeV in 600 ms. The fractional tune components that were measured are presented in two graphical formats showing the time-resolved measurement of the horizontal and vertical tunes. This experiment demonstrated that the current in the booster was extremely sensitive to the ratio of BF to BD combined-function magnets. Large variations of the fractional tunes were found to follow the differences in the gradients of the BD and BF combined-function magnet ramping curves and with this knowledge, alterations were made to the ramping table increasing the efficiency of the booster by on average 40%. Rapid fluctuation of the tunes meant that it could not be distinguished during the first 80ms of the ramp. Multiple side bands to the revolution harmonic were visible during a minimal sweep time of 2.5ms, during this first 80ms.

• R.M. Seraphim, O.R. Bagnato, F.H. Cardoso, R.H.A. Farias, R.O. Ferraz, H.G. Filho, F. R. Francisco, G.R. Gomes, S.R. Marques, R.T. Neuenschwander, F. Rodrigues, A.L. Rosa, M.B. Silva, M.M. Xavier
  LNLS, Campinas
• P.F. Tavares
  Karlsruhe Institute of Technology (KIT), Karlsruhe

In the beginning of 2008 an upgrade of the beam position monitors (BPMs) of the Brazilian Synchrotron Light Source (LNLS) electron storage ring was decided and scheduled as part of the continuous effort to improve the electron beam orbit stability. The objective was to replace most of the 24 BPMs installed in the storage ring and install new radiation absorbers inside the vacuum chamber. The original stripline BPMs were sensitive to temperature changes in the vacuum chamber. Heat, which induced mechanical stress in the striplines, could lead to fluctuations in the position readings thereby disturbing the orbit stability. The problem affected differently the BPMs. Although not a great issue during a typical user shift, the perturbations could pose some problems for the most sensitive experiments. One third of the BPMs were replaced in October 2008 and the remaining in October 2009. Thus, this large vacuum intervention aimed at improving the thermal and mechanical stability of the electron beam orbit measurement system. Finally, it will be presented the main changes made in the vacuum chambers and a survey of the evolution of the vacuum system after both interventions.

• F.H. Cardoso, J.F. Citadini, S.R. Marques, X.R. Resende, R.M. Seraphim
  LNLS, Campinas

The main facility of the Brazilian Synchrotron Light Laboratory is a 93 meters circumference, 1.37 GeV storage ring. Recently, the first superconducting insertion device was installed in the machine. This 4 T ID produces powerful beams that can damage the non-cooled parts of the accelerator vessel in the case of a miss-steered beam, even with a relatively large vacuum chamber cross section. In this paper we present the design details and the first operational results of the electronic beam position interlock system. Topics about redundancy engineering will be discussed as well.

• L. Liu, X.R. Resende, A.R.D. Rodrigues
  LNLS, Campinas

We report on the status of SIRIUS (BR), the new 3 GeV synchrotron light source currently being designed at the Brazilian Synchrotron Light Laboratory (LNLS) in Campinas, Brazil. The new light source will consist of a low emittance storage ring based on the use of permanent magnet technology for the dipoles. An innovative approach is adopted to enhance the performance of the storage ring dipoles by combining low field (0.5 T) magnets for the main beam deflection and a short slice of high field magnet. This short slice will create a high bending field (2.0 T) only over a short longitudinal extent, generating high critical photon energy with modest energy loss from the complete dipole. There are several attractive features in this proposal, including necessity for lower RF power, less heating of the vacuum chambers and possibility to reduce the beam emittance by placing the longitudinal field gradient at a favorable place.

• L.O. Dallin, W.A. Wurtz
  CLS, Saskatoon, Saskatchewan

Preliminary observations of coherent synchrotron radiation (CSR) at the Canadian Light Source have been reported earlier. At that time a more suitable operating point was identified based on particle tracking calculations. These calculations showed that a large stable longitudinal phase space can be achieved through adjustment of the chromaticities. With the implementation of these operating conditions CSR has been produced with much improved beam lifetime. CSR has been produced both with multiple bunches at 1.5 GeV and with a single bunch at the nominal 2.9 GeV beam energy. The production of CSR with these new operating points has proven to be reliable and repeatable. Operations at the nominal beam energy allows for setup times of under 20 minutes. With a beam lifetime (1/e) of over 7 hours single shifts dedicated to CSR production are now practical.

• S.P. Møller, N. Hertel, J.S. Nielsen
  ISA, Aarhus

At Aarhus University in Denmark, a new synchrotron radiation source is being built. The 46-m circumference storage ring with 6-fold symmetry will operate at 580 MeV to produce bright UV and soft x-ray radiation. The storage ring will have a horizontal emittance of around 10 nm. Four straight sections will be available for insertion devices including a 12-pole wiggler with a field of 2 Tesla. ASTRID2 will operate in top-up mode with electrons from the present storage ring ASTRID, used as a booster. The insertion devices will have a strong influence on the lattice, and studies of dynamical aperture and compensation of tunes and beta beat will be presented. Also injection simulations will be given. The technical layout with details about magnetic arrangements on girders will be shown, including the vacuum system with extensive use of NEG. A 10⁵ MHz RF system is being built together with a new LLRF system. At present, most major components have been ordered, and first injection will take place in the first half of 2011.

• A.S. Setty, D. Jousse, J.-L. Pastre
  THALES, Colombes
• E. Weihreter
  Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Elektronen-Speicherring BESSY II, Berlin

A turn key 50 MeV linac is under construction, in order to inject electrons into the booster of BESSY II synchrotron in replacement of the existing microtron. The linac will deliver electrons according to two operations modes: a Short Pulse Mode (< 1 ns - 0.35 nC) and a Long Pulse Mode (40 to 300 ns - 3 nC). We have calculated the beam dynamics using our in house code, PRODYN *, from the gun to the end of the linac. This code has been previously used for the beam dynamics of the SOLEIL and ALBA linacs. The beam behaviour, such as the radial control, the bunching process, the energy spread and emittance are analysed.

* A.Setty, "Electrons RF auto-focusing and capture in bunchers", Linear Accelerator Conference 1988, Virginia.

• J.-M. Filhol, J.C. Besson, P. Brunelle, M.-E. Couprie, J.-C. Denard, C. Herbeaux, J.-F. Lamarre, P. Lebasque, M.-P. Level, P. Marchand, A. Nadji, R. Nagaoka
  SOLEIL, Gif-sur-Yvette

The SOLEIL synchrotron light source is now delivering photons to 20 beamlines with a current of 400 mA in top-up mode. The long and short term H and V beam position stabilities are in the range of one micron thanks to the efficient slow and fast orbit feedbacks, and to the improved tunnel temperature regulation. The bunch by bunch transverse feedback is running with two independent H and V loops. To enable canted undulator implementations, a 3 magnet chicane has been installed in a medium straight whereas an additional triplet of quadrupole was inserted in the middle of a long straight to create a double low vertical beta. 17 insertion devices are now installed in the storage ring, 2 will be added early 2010, 8 are under construction, including a cryogenic undulator. Following the significant progression of the vacuum conditioning, the lifetime is now mainly Touchek limited. An electron bunch slicing set-up is also being installed to provide 100 fs long X-rays pulses to two existing beamlines. ~4500 hours will have been delivered in 2009 to the Beamlines with an availability above 96 % thanks to the very reliable operation of the unique SOLEIL RF system.

• A. Loulergue, C. Benabderrahmane, F. Bouvet, P. Brunelle, M.-E. Couprie, J.-C. Denard, J.-M. Filhol, C. Herbeaux, P. Lebasque, V. Leroux, A. Lestrade, O. Marcouillé, J.L. Marlats, F. Marteau, T. Moreno, A. Nadji, L.S. Nadolski, F. Polack, A. Somogyi, M.-A. Tordeux
  SOLEIL, Gif-sur-Yvette

SOLEIL is the French 2.75 GeV high brilliance third generation synchrotron light source delivering photons to 20 beamlines with a current of 400 mA in multibunch or hybrid modes, and 60 mA in 8 bunch mode. There are already 17 insertion devices installed and 9 others are planned in the next 2 coming years. Among them, two canted in vacuum insertion devices are planned, for the Nanoscopium and Tomography beamlines, and will be accommodated in a 12 m long straight section, with a 6.5 mrad separation angle. These ~150 m long beamlines will exploit the high brilliance and coherence characteristics of the X-ray (5-20 keV) beam both for diffraction limited focusing and for contrast formation. To provide low vertical beta functions at each undulator, an extra triplet of quadrupoles was added in the middle of the section. We present here the lattice implementation footprint, the different working point under investigations as well as the first results of the measurements on the machine performances.

• A. Nadji, F. Briquez, M.-E. Couprie, J.-C. Denard, J.-M. Filhol, C. Herbeaux, Ph. Hollander, M. Labat, J.-F. Lamarre, C. Laulhe, V. Leroux, O. Marcouillé, J.L. Marlats, T. Moreno, P. Morin, P. Prigent, S. Ravy, F. Sirotti
  SOLEIL, Gif-sur-Yvette
• J. Luning
  UPMC, Paris
• M. Meyer
  LIXAM, Orsay

An electron bunch slicing set-up is being installed on the SOLEIL storage ring, based on Zholents and Zolotorev method [1]. This will provide 100 fs long X-ray pulses with reasonable flux to two existing beamlines, working with soft X-rays (TEMPO) and hard X-rays (CRISTAL). The parameters of the laser system and of the wiggler modulator, and the optimisation of the laser focusing optics and beam path, from the laser hutch in the experimental hall to the inside of the storage ring tunnel have been finalised. The construction work will start early 2010, including the ordering of the laser, the construction of the laser hutch, the construction of the wiggler, the installation of a new modified vacuum dipole chamber by which the laser will enter into the ring, and the modifications of some components in the beamlines front-ends to provide the best possible separation of the sliced X-Ray. In this paper, we will report on the status of the installation of the set-up and the expected performances including laser-electron interaction efficiency, halo background effect and the possible operation filling patterns.

• J.-L. Revol, J.C. Biasci, J-F. B. Bouteille, J. Chavanne, P. Elleaume, F. Ewald, L. Farvacque, F. 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

After 15 years of highly successful user operation, the Council of the ESRF are funding an ambitious 7 year upgrade programme (2009-2015) of the European Synchrotron Radiation Facility. In this context the accelerator complex will benefit from a number of upgrades. Several insertion device straight sections will be lengthened from five to six meters. The beamline scientific capacities will be increased by operating some straight sections in the canting geometry. New insertion devices will be built to fulfill the requirements of the scientific programme. The RF system also faces a major reconstruction with the replacement of some klystron based transmitters by high power solid state amplifiers and the development of HOM damped cavities operating at room temperature. The orbit stabilisation system system will be renovated. This paper reports on the present operation performances of the source, highlighting the recent development, as well as the advancement of the upgrade projects.

• P.O. Schmid, P. Kuske
  Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin
• D.B. Engel, J. Feikes, R. Müller, G. Wüstefeld
  Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Elektronen-Speicherring BESSY II, Berlin

In this paper we present the results of our studies employing LOCO and MML for optics calibration at the MLS and at the BESSY II storage rings. Both the standard user modes and dedicated low alpha modes were analysed.

• G. Wüstefeld, J. Feikes, M.V. Hartrott, M. Ries
  Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Elektronen-Speicherring BESSY II, Berlin
• A. Hoehl, R. Klein, R. Müller, A. Serdyukov, G. Ulm
  PTB, Berlin

The Metrology Light Source* is the first storage ring optimized for THz generation**. It applies a bunch shortening mode, based on a flexible momentum compaction factor 'alpha'. The emitted THz radiation is very sensitive to the machine tuning, its power could vary by many orders of magnitude. We report on coherent THz signal intensities as a function of different machine parameters, such as beam energy, beam current, rf voltage and alpha tuning.

* R. Klein et al., Phys. Rev. ST. Accel. Beams vol. 11, 110701 (2008). ** J. Feikes et al., The Metrology Light Source: The First Electron Storage Ring Optimized for Generating Coherent THz Radiation, submitted to Phys. Rev. ST. Accel. Beams (2009).

• A. Kling, K. Balewski
  DESY, Hamburg

PETRA III is a 3rd generation synchrotron radiation light source which started commissioning in April 2009. Recently, first frequency map measurements have been made using the turn-by-turn capabilities of the beam position monitors and horizontal as well as vertical kicker magnets. The results are in good agreement with expectations from tracking studies performed with SixTrack.

• A. Kling, K. Balewski
  DESY, Hamburg
• R. Bartolini
  JAI, Oxford

PETRA III is a 3rd generation synchrotron radiation light source which started commissioning in April 2009. Turn-by-turn capabilities are available for all 227 BPMs installed in the storage ring thus providing a powerful diagnostic tool for the characterization of the linear and nonlinear motion of the stored beam. We report on first results of beam dynamics studies using multiturn data acquired at PETRA III and first steps towards a calibration of the linear and nonlinear lattice model of the storage ring.

• R. Wanzenberg, K. Balewski
  DESY, Hamburg

At DESY the PETRA ring has been converted into a synchrotron radiation facility, called PETRA III. The commissioning with beam started in April 2009. The betatron tune versus beam intensity was measured for different configurations of the wiggler magnets which are installed in PETRA III to achieve the small emittance of 1 nm. These measurements are compared with predictions from the impedance model. The measured tune shift is well within the impedance budget and the design single bunch intensities of up-to 2.5 mA can be stored in PETRA III. The predicted vertical tune shift is about 30 % smaller than the measured one.

• S. Hillenbrand, M. Fitterer, N. Hiller, A. Hofmann, E. Huttel, V. Judin, M. Klein, S. Marsching, A.-S. Müller, K.G. Sonnad, P.F. Tavares
  KIT, Karlsruhe

The Karlsruhe Institute of Technology (KIT) proposes to build a new light source called TBONE (THz Beam Optics for New Experiments), which aims at a spectral range from 0.1 to 150 THz with a peak power of several MW and a pulse length of only 5 fs. In order to achieve this, a beam transport system with minimal losses and a high bunch compression is required. In this paper we present first beam dynamic simulations of the superconducting linac as well as the bunch compressor and give a short status report of the TBONE project.

• N. Hiller, S. Hillenbrand, A. Hofmann, E. Huttel, V. Judin, B. Kehrer, M. Klein, S. Marsching, A.-S. Müller, A. Plech, N.J. Smale, K.G. Sonnad, P.F. Tavares
  KIT, Karlsruhe

A dedicated optics with a low momentum compaction factor is used at the ANKA storage ring to reduce the bunch length to generate coherent synchrotron radiation (CSR). A double sweep streak camera is employed to determine the bunch length and shape for different optics and as a function of the beam current. Measurements of the longitudinal bunch profile have been performed for many different momentum compaction factors and various bunch currents. This paper describes the set up of the streak camera experiments and compares the measured bunch lengths to theoretical expectations.

• V. Judin, S. Hillenbrand, N. Hiller, A. Hofmann, E. Huttel, M. Klein, S. Marsching, A.-S. Müller, N.J. Smale, K.G. Sonnad, P.F. Tavares
  KIT, Karlsruhe
• H.W. Huebers
  Technische Universität Berlin, Berlin
• A. Semenov
  DLR, Berlin

Since a few years CSR-Radiation created in low alpha mode is provided by the ANKA light source of the KIT*. Depending on the bunch current, the radiation is emitted in bursts of high intensity. These bursts display a time evolution which can be observed only on long time scales with respect to the revolution period. The intensity of the emitted radiation during a burst is significantly increased w.r.t. steady state emission. Some users of the THz radiation don't require particularly constant emission characteristics and could profit from the higher intensity. A better understanding of the long term behaviour of those bursts could help to improve the conditions for those users. We have investigated THz radiation in multiturn mode with a hot electron bolometer. Its time response of 165ps allowed us to resolve the signals of individual bunches. Using a 6GHz LeCroy oscilloscope for data acquisition, we were able to save up to 1.6ms long signal sequences at a sampling rate of 20GS/s. This amount of data corresponds to over 4000 bunch revolutions and allows turn-by-turn signal tracking of desired bunches. In single bunch mode we are able to take segmented data to avoid a huge overhead.

* KIT - Karlsruhe Institute for Technology

• A.-S. Müller, I. Birkel, M. Fitterer, S. Hillenbrand, N. Hiller, A. Hofmann, E. Huttel, K.S. Ilin, V. Judin, M. Klein, S. Marsching, Y.-L. Mathis, P. Rieger, M. Siegel, N.J. Smale, K.G. Sonnad, P.F. Tavares
  KIT, Karlsruhe
• H.W. Huebers
  Technische Universität Berlin, Berlin
• A. Semenov
  DLR, Berlin

In synchrotron radiation sources coherent radiation is emitted when the bunch length is comparable to or shorter than the wavelength of the emitted radiation. At the ANKA storage ring this radiation is observed as so-called edge radiation (emitted in the fringe field of a bending magnet). This radiation exhibits a radial polarisation pattern. The observed pattern, however, is influenced by the radiation transport in the beam line. A detector system based on a superconducting NbN ultra-fast bolometer with an intrinsic response time of about 100 ps as well as conventional Si bolometers were used to study the beam polarisaion. This paper reports the observations made during measurements.

• J. Rahighi
  IPM, Tehran

An overview of the 3 GeV Synchrotron radiation source, which is under design in Iran will be presented with emphasis on site location studies, user demands and general parameters of the machine. The background to the proposed facility and different aspects of the machine design also is reported. Operating this third generation light source with 3 GeV storage ring and beam currents of up to 400mA, will result in a source of very intense light over a broad range of photon energies from the IR to hard X-rays to a community that is expected to exceed 500 users a few years after the start of operation in 2015 .

• H. Ghasem
  IPM, Tehran
• H. Hassanabadi
  Shahrood University of Technology, Shahrood
• A. Mohammadzadeh
  NSTRI, Tehran

The effects of utilizing a third harmonic RF cavity in the lengthening mode have been investigated on quality of the electron beam and the emitted photons in the deflecting RF structures for TPS. For the obtained optimum synchronous and relative harmonic phases and harmonic voltage of 0.7 MV, the equilibrium horizontal and vertical emittances blow up as much as 13% and 97%, respectively. In addition, the intensity of the emitted X-ray pulses with 0.54 ps FWHM reduces by 30%.

• H. Ghasem
  IPM, Tehran
• G.-H. Luo
  NSRRC, Hsinchu
• A. Mohammadzadeh
  NSTRI, Tehran

A pair of superconducting crab cavities has been studied in the QBA low emittance lattices of the 3 GeV TPS for generating ultra short X-ray pulses. Three configurations with different locations for the two cavities in a super-period of the TPS ring are investigated. The configuration with positioning the RF deflectors between the QBA cells in each super-period as an optimum arrangement gives rise to better quality electron bunches and radiated photon pulses. The FWHM of the radiated photon pulses of about 540 fs with an acceptable intensity is attained by optimizing the compression optical elements of the TPS photon beam line.

• M. Mostajeran, M. Lamehi Rachti
  IPM, Tehran

The effect of surface roughness on the secondary electron emission from a sandblasted surface is investigated using a Monte-Carlo method. Sandblasted surfaces can significantly reduce the secondary emission yield and have a large sensitivity to the percentage of surface roughness.

• E. Karantzoulis, A. Carniel, K. Casarin, S. Ferry, G. Gaio, F. Giacuzzo, S. Krecic, E. Quai, C. Scafuri, G. Tromba, A. Vascotto, L. Zambon
  ELETTRA, Basovizza

Elettra established top-up operations taking advantage of its new full energy injector. The safety simulations and personnel safety conditions, the radiation measurements, the implementation and the operations of the whole system are presented and discussed.

• A. Miyamoto, K. Goto, S. Sasaki
  HSRC, Higashi-Hiroshima
• S. Hanada
  Hiroshima University, Graduate School of Science, Higashi-Hiroshima
• H. Tsutsui
  SHI, Tokyo

The HiSOR is a synchrotron radiation (SR) source of Hiroshima Synchrotron Radiation Center (HSRC), Hiroshima University, established in 1996. HiSOR is a compact racetrack-type storage ring having 21.95 m circumference, and 400-nmrad natural emittance, which is not so small compared with those of other medium~large storage rings. There are 14 beamlines on HiSOR, but the ring has only two straight sections for undulators which are obviously not compatible with modern SR facilities. Therefore, we are planning to construct a compact storage ring, 'HiSOR-II' in which undulators are dominant light sources. We refer to the electron storage ring MAX-III as the best models to design HiSOR-II lattice. This 700 MeV storage ring is designed that the circumference is equal to or less than 50 m so that it can fit in our existing site. It has several straight sections for undulators, and its natural emittance is about 14nmrad. The booster ring aiming for the top-up injection is constructed on the inside basement of HiSOR-II. This layout brings advantages in radiation shielding and prevention of magnetic field interference between two rings.

• S. Hashimoto, S. Miyamoto
  NewSUBARU/SPring-8, Laboratory of Advanced Science and Technology for Industry (LASTI), Hyogo
• K. Kawata, Y. Minagawa, T. Shinomoto
  JASRI/SPring-8, Hyogo-ken

The periodic fluctuations and drifts in the radiation intensity have been observed at the NewSUBARU synchrotron radiation facility. To clarify the cause of this problem we have measured temperatures of air, cooling water, equipments and building with the network-distributed data logger. And we found that temperature fluctuations in both air in the shielded tunnel and the cooling water mainly affect the stabilities of electron beam orbit and optical axis. To maintain a constant temperature, the large doors for carrying equipment at the experimental hall were covered with insulated curtains, and we optimized PID parameters of temperature controllers for air and water. As results, the periodic fluctuations almost disappeared, but some drifts were still remained, which are due to slow variations of equipment temperature. By realizing the automatic COD correction, the drift in electron beam position could be suppressed and the fluctuations of radiation intensity observed at beam-lines became smaller than they used to be. For further stabilization, we recently introduced a XBPM upstream in a beamline to measure the vertical position of radiation axis precisely.

• C. Mitsuda, K. Fukami, K. Kobayashi, M. Oishi, Y. Okayasu, M. Shoji, K. Soutome, H. Yonehara
  JASRI/SPring-8, Hyogo-ken
• T. Nakanishi
  SES, Hyogo-pref.
• T. Ohshima
  RIKEN/SPring-8, Hyogo

In top-up operation at SPring-8 the horizontal beam oscillation had been excited because the injection bump orbit is not closed perfectly. For this problem, we had made an effort to reduce the residual beam oscillation by the improvement of bump magnet design, reducing the effect due to the nonlinearity of sextupole magnet and introducing pulsed corrector magnet, etc. By these improvements the average amplitude of residual oscillation has now been suppressed to the level of less than 0.1 mm. Still remaining relatively large residual oscillation comes from a non-similarity of a temporal shape of magnetic field of four bump magnets. We then started development fast kicker magnet system to give a counter kick to this part of residual beam oscillation. A key technology in this development is how to generate a large pulsed current in a short period to meet the oscillation characteristic. A newly developed fast pulsed power supply can generate a current of about 300 A, or corresponding magnetic field of 4.61 mT, with a pulse width of 1.2 us. Recently, we succeeded in the reduction of the horizontal beam oscillation at the timing of firing bump magnets by using this kicker system.

• K. Soutome, H. Ohkuma, J. Schimizu, Y. Shimosaki, M. Takao
  JASRI/SPring-8, Hyogo-ken

The SPring-8 storage ring has been operated for more than ten years and provided brilliant hard X-ray radiation to users. In recent years there are some discussions on upgrade plans of existing synchrotron radiation facilities and proposals of new facilities. In these the target brilliance of photons is set to be comparable or even higher, in some energy range, than that of the present value of SPring-8. At SPring-8 a design study of a new storage ring is now in progress for the future upgrade plan. The lattice structure will be changed from the present double-bend type to the multi-bend one, keeping the source position of all insertion devices unchanged. The emittance will be lowered from the present value of 3.4nmrad at 8GeV to 0.4nmrad at 6GeV (or 0.8nmrad at 8GeV) in the case of triple-bend lattice and 0.2nmrad at 6GeV (or 0.3nmrad at 8GeV) in the case of quadruple-bend lattice. We will report the present state of our preliminary work on lattice design. Nonlinear resonance correction to enlarge the dynamic aperture for on- and off-momentum electrons will also be discussed.

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

We indicated that a storage ring with picometer-order emittance is possible with realistic parameters and is promising as a next generation synchrotron radiation source* and applied it to the SPring-8 storage ring**. The storage ring had the same circumference as that of the SPring-8 storage ring, but had not four long straight sections that SPring-8 storage ring has. Accordingly, the storage ring beam line is slightly different from that of the SPring-8 and the positions of photon beam lines are also different from the existing one. To avoid this, a storage ring with four long straight sections has been studied and was found that the storage ring with the same beam line positions as the existing one is possible. The storage ring consists of twenty ten-bend achromat cells, four five-bend achromat cells and four long straight sections. The long straight section length is 34.0 m and the short one is 6.6 m. The natural emittance is 10⁸ pm-rad. The maximum brightness is 2.5×10²² photons/s/mm**2/mrad**2 in 0.1% BW with 200 mA beam current, about 160 times brighter than SPring-8. In the end I mention that this ultra-low emittance storage ring is only a result of personal design study.

* K. Tsumaki and N. Kumagai, Nucl. Instr. and Meth. A 565 (2006) 394.
** K. Tsumaki and N. Kumagai, EPAC'06, 3362.

• T. Honda, T. Aoto, S. Asaoka, K. Ebihara, K. Furukawa, K. Haga, K. Harada, Y. Honda, T. Ieiri, N. Iida, M. Izawa, T. Kageyama, M. Kikuchi, Y. Kobayashi, K. Marutsuka, A. Mishina, T. Miyajima, H. Miyauchi, S. Nagahashi, T.T. Nakamura, T. Nogami, T. Obina, K. Oide, M. Ono, T. Ozaki, C.O. Pak, H. Sakai, H. Sakai, Y. Sakamoto, S. Sakanaka, H. Sasaki, Y. Sato, K. Satoh, M. Shimada, T. Shioya, M. Tadano, T. Tahara, T. Takahashi, R. Takai, S. Takasaki, Y. Tanimoto, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, M. Yamamoto, Ma. Yoshida, S.I. Yoshimoto
  KEK, Ibaraki

KEK manages two synchrotron radiation sources, Photon Factory storage ring (PF-ring) of 2.5 GeV and Photon Factory advanced ring (PF-AR) of 6.5 GeV. These rings share an injector linac with the two main rings of KEK B-factory, 8-GeV HER and 3.5-GeV LER. Recently, the linac has succeeded in a pulse by pulse multi-energy acceleration. A top-up operation of PF-ring has been realized as the simultaneous continuous injection to the 3 rings, PF-ring, HER and LER. Development of new injection scheme using a pulsed sextupole magnet continues aiming at practical use in the top-up operation. A rapid-polarization-switching device consisting of tandem two APPLE-II type undulators has been developed at PF-ring. The first undulator was installed in 2008, and the second one will be installed in 2010 summer. PF-AR, operated in a single-bunch mode at all times, has been suffered from sudden lifetime drop phenomena attributed to dust trapping for many years. Using the movable electrodes installed for experiment, we confirmed that the discharge created by the electrode was followed by the dust trapping, and succeeded in a visual observation of luminous dust streaking in front of CCD cameras.

• R. Takai, T. Honda, Y. Kobayashi, T.M. Mitsuhashi, T. Obina, M. Shimada, Y. Tanimoto
  KEK, Ibaraki

A hybrid fill mode has been tested at the Photon Factory storage ring (PF-ring). The hybrid fill mode consists of a train of low-current bunches and a high-current single bunch. Since a bunch-by-bunch feedback system was not available because of the high contrast of currents between the bunch train and the single bunch, we suppressed multibunch instabilities in the transverse and longitudinal planes by using the octupole magnets and RF phase modulation, respectively. We also suppressed single-bunch instabilities by controlling ring chromaticity. As a result, we successfully stored a 450 mA current with the hybrid fill mode: 1/2 filling (2.56 mA/bunch × 156) + 1 single bunch opposite to the bunch train (50 mA/bunch). The distribution of vacuum pressures along the ring was similar for the hybrid fill and the typical single-bunch mode. In this conference, we will present the results of this test experiment as well as some future subjects to be solved for the user operation.

• N. Yamamoto, M. Hosaka, H. Morimoto, K. Takami, Y. Takashima
  Nagoya University, Nagoya
• Y. Hori
  KEK, Ibaraki
• M. Katoh
  UVSOR, Okazaki
• S. Koda
  SAGA, Tosu
• S. Sasaki
  JASRI/SPring-8, Hyogo-ken

Central Japan Synchrotron Radiation (SR) Research Facility is under construction in the Aichi area, and the service will start from FY2012. Aichi Science & Technology Foundation is responsible for the operation and management, and Nagoya University SR Research Center is responsible to run the facility and support the users technically and scientifically. The accelerators consists of an injector linac, a booster synchrotron and an 1.2 GeV electron storage ring with the circumference of 72 m. To save construction expenses, the 50 MeV linac and the booster with the circumference of 48 m are built at inside of the storage ring. The beam current and natural emittance of the storage ring are 300 mA and 53 nmrad. The magnetic lattice consists of four triple bend cells and four straight sections 4 m long. The bending magnets at the centers of the cells are 5 T superbends and the critical energy of the SR is 4.8 keV. More than ten hard X-ray beam-line can be constructed. One variable polarization undulator will be installed in the first phase. The electron beam will be injected from the booster with the full energy and the top-up operation will be introduced as early as possible.

• N. Yamamoto, M. Hosaka, Y. Taira, Y. Takashima
  Nagoya University, Nagoya
• M. Adachi, M. Katoh, S.I. Kimura, H. Zen
  UVSOR, Okazaki
• M. Shimada
  KEK, Ibaraki
• T. Takahashi
  KURRI, Osaka
• T. Tanikawa
  Sokendai - Okazaki, Okazaki, Aichi

Terahertz (THz) coherent synchrotron radiation (CSR) is emitted not only from shorter electron bunches compared with the radiation wavelength but also from electron bunches withμstructures. Formation ofμstructures at sub picosecond scale in electron bunches by a laser slicing technique is experimentally studied through observation of THz CSR. The properties of the THz CSR such as intensity or spectrum depend strongly on the shape and amplitude of theμstructure created in the electron bunches. To study in detail the formation ofμstructure in electron bunches using the laser slicing technique, we have performed experiments at the UVSOR-II electron storage ring. THz CSR, which contains information on theμstructure, was observed under various laser conditions. The THz CSR spectrum was found to depend strongly on the intensity and the pulse width of the laser. The results agreed qualitatively with a numerical calculation. It was suggested that the evolution of theμstructure during CSR emission is important under some experimental conditions.

• M. Adachi, K. Hayashi, M. Katoh, S.I. Kimura, J. Yamazaki, H. Zen
  UVSOR, Okazaki
• M. Hosaka, Y. Taira, Y. Takashima, N. Yamamoto
  Nagoya University, Nagoya
• T. Takahashi
  KURRI, Osaka
• T. Tanikawa
  Sokendai - Okazaki, Okazaki, Aichi

UVSOR, a 750 MeV synchrotron light source of 53m circumference had been operated for more than 20 years. After a major upgrade in 2003, this machine was renamed to UVSOR-II. The ring is now routinely operated with low emittance of 27 nm-rad and with four undulators. By utilizing a part of the existing FEL system and an ultra-short laser system, coherent synchrotron radiation in THz range and coherent harmonic generation in VUV range have been extensively studied under international collaborations. Based on results obtained from previous coherent light source developments, a new five-year research program on the coherent light source developments has been started from FY2008, which includes creation of a new 4-m long straight section by moving the injection point, upgrades of the undulator and the laser system and construction of dedicated beam-lines for these coherent light sources. Present status and upgrade plan on these coherent light sources at UVSOR-II will be presented at the conference.

• H. Zen, K. Hayashi, J. Yamazaki
  UVSOR, Okazaki
• M. Adachi, M. Katoh, T. Tanikawa, H. Zen
  Sokendai - Okazaki, Okazaki, Aichi
• M. Hosaka, Y. Taira, N. Yamamoto
  Nagoya University, Nagoya

UVSOR-II is a low emittance, 750 MeV synchrotron light source. Low emittance and low energy synchrotron light sources naturally suffered from short electron lifetime due to Touschek effect. Top-up operation is a solution for overcoming the effect. In the UVSOR-II, trials of multi-bunch top-up operation at the full energy were started from 2008. In the trials, we have succeeded in keeping the stored beam current around 300 mA for 12 hours. From this fiscal year, single bunch injection was started for single bunch user operations and for experiments on advanced light source development such as Free Electron Laser (FEL), Coherent Synchrotron Radiation (CSR), Coherent Harmonic Generation (CHG), which require single bunch or 2-bunch filling operation. We have already performed single bunch top-up operation in user time with the stored beam current of 50 mA. And FEL lasing with top-up operation was also achieved at the laser wavelength of 215 nm with the stored beam current of 130 mA / 2-bunch. In the FEL lasing experiment, we succeeded in keeping the average power of FEL around 130 mW for three hours.

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

Saga Light Source (SAGA-LS) is a synchrotron radiation facility with a 255 MeV linac and a 1.4 GeV storage ring. The spectral range covers from VUV to hard X ray region of about 23 keV. Improvement and development of the accelerator have been achieved from official opening of the facility. Stored current of the storage ring has been increased from 100 mA to 300 mA in these three years. An APPLE-2 undulator was developed and installed to a long straight section LS3. A field correction system for the undulator was developed to compensate precisely betatron tune shift, dipole kick and skew quadrupole. A superconducting wiggler is under construction. The peak field and critical energy are 4 T and 5.2 keV, respectively. The wiggler will provide synchrotron radiation in the 20-40 keV range. The wiggler consists of a superconducting main pole and two normal conducting side poles. The main pole is directly cooled by a small GM cryocooler and liquid helium is not used. In addition, laser Compton scattering experiment is under progress. A port to introduce CO₂ laser light was installed as a beam line BL1. First gamma ray was observed in December 2009.

• W. Fan, G. Feng, D.H. He, W. Li, L. Wang, S.C. Zhang
  USTC/NSRL, Hefei, Anhui

Hefei Advanced Light Source(HALS) will be a high brightness light source with about 0.2nmrad emittance at 1.5GeV and about 400m circumference. To enhance brilliance, very low beam emittance is required. High brightness demand and relative low energy will make emittance a critical issue in ring design. Intra-beam scattering(IBS) is usually thought a fundamental limitation to achieve low emittance. Here we preliminarily estimate the emittance growth due to IBS for the temporary lattice design of HALS based on Piwinski and Bjorken-Mtingwa theories, and discuss the effect of implementation of damping wiggler and harmonic cavity to lower the emittance.

• G. Feng, W. Fan, W.W. Gao, W. Li, L. Wang, H. Xu, S.C. Zhang
  USTC/NSRL, Hefei, Anhui

HLS (Hefei Light Source) is a dedicated synchrotron radiation research facility, whose emittance is relatively large. In order to improve performance of the machine, especially getting higher brilliance synchrotron radiation and increasing the number of straight sections for insertion devices, an upgrade project is on going. A new low emittance lattice, which keeps the circumference of the ring no changing, has been studied and presented in this paper. For the upgrade project, a new ring will be installed on current ground settlement of HLS and all of the magnets will be reconstructed. After optimization, two operation modes have been chosen for different users. Nonlinear dynamics shows that dynamic aperture for on-momentum and off-momentum particle is large enough. Beam lifetime has also been studied. Calculation results proves that expected beam lifetime about 8.5 hours can be obtained with a fourth harmonic cavity operation.

• L. Wang, W. Fan, G. Feng, W.W. Gao, W. Li, H. Xu, S.C. Zhang
  USTC/NSRL, Hefei, Anhui

The Hefei Light Source is composed of an 800 MeV storage ring, a 200 MeV electron linac and transfer line, which was designed and constructed twenty years ago. Several factors limit the performance of HLS, for example, less number of insertion devices and large beam emittance. To meet the requirements of synchrotron radiation users, an upgrade project of HLS will be carried out in the next two years. Several sub-systems will be renewed, such as magnet system, power supply, beam diagnostics, vacuum system, etc. The upgrade scheme is described in this paper, including magnet lattice design, nonlinear performance, collective effects,beam injection, orbit detection and correction, injector, etc.

• H.H. Li, J. Hou, B.C. Jiang, L.G. Liu, X.Y. Sun, S.Q. Tian, M.Z. Zhang, W.Z. Zhang
  SINAP, Shanghai

The SSRF (Shanghai Synchrotron Radiation Facility) storage ring consisting of 20 Double Bend Achromatic cells with four super-periods is designed with a low emittance of 3.9nm.rad on 3.5GeV beam energy. Commissioning of the storage ring began on Dec. 21st 2007, and the beam was stored within sixty hours. After one and a half years commissioning, all specifications of the storage ring were reached in 2009. In this paper, study of beam dynamics in the SSRF storage ring is presented. Results of the measurement are given in detail, such as model calibration, orbit stability, etc.

• J.F. Liu, H.T. Hou, C. Luo, Zh.G. Zhang, S.J. Zhao
  SINAP, Shanghai
• Z.Q. Feng, Z. Li, D.Q. Mao, Y.B. Zhao, X. Zheng
  Shanghai KEY Laboratory of Cryogenics & Superconducting RF Technology, Shanghai

The superconducting RF system has been operated successfully in the storage ring of SSRF since July, 2008. The superconducting RF modules integrated with 310 kW transmitters and digital low level radio frequency (LLRF) control are adopted to provide about 4.5 MV cavity voltages to 3.5GeV electron beam. The operation status of SRF system is mainly reported here, the problems we met are analyzed, and the operation with normal conducting cavity systems is introduced briefly. The challenge for us is to improve the system reliability and machine performance.

• S.Q. Tian, H.H. Li, X.Y. Sun, M.Z. Zhang, W.Z. Zhang
  SINAP, Shanghai

Beam optics design is a crucial issue in modern synchrotron radiation facility. A design approach of the beam optics is presented here. It provides much convenience for effectively exploring achievable linear optics and globally investigating flexibility of a complex lattice with super-periodicity. Low-ε optics and low-αC optics are emphasized, and the SSRF storage ring is taken as a test lattice.

• H. Yu
  SSRF, Shanghai
• M. Chen, Z.Q. Feng, H.T. Hou, J.F. Liu, Z.Y. Ma, D.Q. Mao, B. Yin
  SINAP, Shanghai

To investigate the higher order mode(HOM) damping in the higher harmonic cavity for Shanghai Synchrotron Radiation Facility(SSRF) when using HOM absorbers,simulations have been done for changing the position and the length as well as the thickness of ferrite of HOM damper. The best values under which the Q value of HOMs can be greatly lowered and the impedance of harmonic cavity will be trapped in the impedance threshold have been found.

• K.-H. Park, H.S. Han, Y.-G. Jung, D.E. Kim, K.R. Kim, H.-G. Lee, H.S. Suh
  PAL, Pohang, Kyungbuk
• B.-K. Kang
  POSTECH, Pohang, Kyungbuk

The PAL (Pohang Accelerator Laboratory) has been carrying out the performance upgrade project, PLS-II. The lattice of the storage ring for PLS-II was changed in whole. The energy was increase from 2.5GeV to 3.0GeV thus many magnets installed in storage ring at present should be replaced with new one or modified. The field of the quadrupole and sextupole magnets will be measured using the rotating coils that are newly fabricated with the engineering ceramic for the first time at PAL. The data acquisition system for the field measurement was also rebuilt to make it simple and to have a good signal to noise ratio. In this presentation, the design parameters of the ceramic rotating coil are described. And various characteristics of the field measurement system are also presented

• D. Einfeld
  CELLS-ALBA Synchrotron, Cerdanyola del Vallès

The Synchrotron Light source ALBA is entering the commissioning period and beam should be provided to the users by the end of 2010. The installation of the full energy 3 GeV booster is finished, with the commissioning taking place in January 2010. The installation of the storage ring is almost finished and the commissioning should take place in summer 2010. The detailed milestones of the project are presented.

• J. Campmany, D. Einfeld, J. Marcos, V. Massana
  CELLS-ALBA Synchrotron, Cerdanyola del Vallès

The new 3rd generation synchrotron radiation source ALBA built nearby Barcelona is planned to start operation in 2010 with several different insertion devices installed in the storage ring either from the beginning or within the first year of operation. The list of first insertion devices includes: 2 planar PPM SmCo in-vacuum undulators with the period of 21.6 mm; 2 Apple-II type PPM NdFeB undulators with the periods of 62.36 and 71.36 mm respectively; 1 superconducting planar wiggler with the period of 30 mm and a maximum field of 2.1 T, and a 1 conventional wiggler with the period of 80.0 mm and a maximum field of 1.74 T. The emitted light of these IDs covers wide spectral range extending from hard X-rays to UV. Pre-design of the IDs was done by ALBA, but manufacturing has been outsourced. Production is now finished and they have been tested with magnetic measurements. The paper will present the final as build magnetic designs as well as the main results of magnetic measurements performed on the manufactured devices.

• G. Benedetti, D. Einfeld, Z. Martí, M. Muñoz
  CELLS-ALBA Synchrotron, Cerdanyola del Vallès

The commissioning of the booster for the synchrotron light source ALBA should take place in the period December 2009-January 2010. In this paper, the beam dynamics aspects of the commissioning are described, including the studies performed, the main problems find during the commissioning and a comparison of the measured beam parameters to the design one. A description of the software tools used and developed for the task is included.

• F. Peréz, A. Salom, P. Sanchez
  CELLS-ALBA Synchrotron, Cerdanyola del Vallès

The Booster of the ALBA synchrotron light source will inject, in top up mode, up to 2 mA of current at 3Hz into the storage ring. The booster ramps the energy from 100 MeV (Linac) up to the 3 GeV of the storage ring. The RF system of the booster consist of a 80 kW IOT amplifier, a WR1800 waveguide system, a 5-cell Petra cavity and a Digital LLRF system. In this paper we will present a short description of the system, its performance during the commissioning phase and the results of operation with beam.

• S.C. Leemann, J. Ahlback, Å. Andersson, M. Eriksson, M.A.G. Johansson, L.-J. Lindgren, M. Sjöström, E.J. Wallén
  MAX-lab, Lund

In 2009 the MAX IV facility was granted funding by Swedish authorities. Construction of the facility will begin this summer and user operation is expected by 2015. MAX IV will consist of a 3.4 GeV linac as a driver for a short-pulse radiation facility (with planned upgrade to a seeded/cascaded FEL) as well as an injector for two storage rings at different energies serving user communities in separate spectral ranges. Thanks to a novel compact multibend-achromat design, the 3 GeV ring will deliver a 500 mA electron beam with a horizontal emittance below 0.3 nm rad to x-ray insertion devices located in 19 dispersion-free 5 m straight sections. When the 3 GeV ring goes into operation in 2015 it is expected to become the highest electron-brightness storage ring light source worldwide. The 1.5 GeV ring will serve as a replacement for both present-day MAX II and MAX III storage rings. Its below 6 nm rad horizontal emittance electron beam will be delivered to infrared and UV insertion devices in twelve 3.5 m straight sections. We report on design progress for the two new storage rings of the MAX IV facility.

• H.-J. Tsai, H.-P. Chang, M.-S. Chiu, P.J. Chou, C.-C. Kuo, W.T. Liu, G.-H. Luo, F.H. Tseng, C.H. Yang
  NSRRC, Hsinchu

Touschek scattering is an important beam lifetime limiting effect for the TPS storage ring due to several challenges such as low emittance, small physical aperture and large second-order momentum compaction factor (nonlinear longitudinal motion). The Touschek relevant energy acceptance is determined by these challenges, therefore a reliable estimate of the Touschek lifetime is essential. We obtained Touschek induced betatron oscillation amplitudes in three sections (LS, SS and ARC) and RF bucket acceptance analytically and with simulations. In this paper, we present the energy acceptance and Touschek lifetime calculations for the TPS storage ring in the cases for different chromaticity settings, ID chamber limitations, magnet multipole field errors and optics correction effects.

• K. Zengin, A.K. Çiftçi, R. Çiftçi
  Ankara University, Faculty of Sciences, Tandogan/Ankara

The Turkish Accelerator Center (TAC) is a project for accelerator based fundamental and applied researches supported by Turkish State Planning Organization (TSPO). The proposed synchrotron radiation facility of TAC was consisted of 3.56 GeV positron ring for a third generation light source. In the first study, it was shown that the insertion devices with the proposed parameter sets produce maximal spectral brightness to cover 10 eV - 100 keV photon energy range. Now, in this study it is considered that the electron beam energy will be increased to 4.5 GeV, in order to obtain more brightness light and wide energy spectrum range, also the beam emittance reduced to 1 nm.rad.

• I.V. Drebot, Yu.N. Grigor'ev, A.Y. Zelinsky
  NSC/KIPT, Kharkov

In the paper the expression for cross section of Compton scattering derived with classical electrodynamics approach is presented. The comparative analysis of the Compton cross section value calculated with the presented expression and with expression derived with quantum approach was carried out for the case of head on collision and low photon beam intensity. Results of the analysis show the good agreement of both approaches. It proves legitimacy of classical electromagnetic approach use for analysis of particle beam dynamics and estimation of generated x-ray beam parameters in laser electron storage rings.

• A.Y. Zelinsky, V.P. Androsov, I.V. Drebot, A.N. Gordienko, V.A. Grevtsev, A. Gvozd, I.I. Karnaukhov, I.M. Karnaukhov, V.P. Kozin, V.P. Lyashchenko, V.S. Margin, N.I. Mocheshnikov, A. Mytsykov, I.M. Neklyudov, F.A. Peev, A.V. Reuzayev, A.A. Shcherbakov, S. Sheyko, V.L. Skirda, Y.N. Telegin, V.I. Trotsenko, N. Varavin, O.D. Zvonarjova
  NSC/KIPT, Kharkov

The status of X-ray generator NESTOR that is under construction in Kharkov Institute of Physics and Technology is described in the paper.

• R. Bartolini, C. Christou, J.H. Han, I.P.S. Martin, J. Rowland
  Diamond, Oxfordshire
• D. Angal-Kalinin, D.J. Dunning, F. Jackson, B.D. Muratori, N. Thompson, P.H. Williams
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

We present the progress with the design of the 2.25 GeV superconducting linac for the NLS project. We discuss the performance achieved, the optimisation strategies, the relevance of microbunching instability and the analysis of the effect of various jitter sources

• C. Christou, J.A. Dobbing, R.T. Fielder, I.P.S. Martin, S.J. Singleton
  Diamond, Oxfordshire

Diamond Light Source has delivered beam for users exclusively in top-up mode since the end of October 2008. In this mode, a small number of single bunches are injected into specific buckets of the storage ring every ten minutes in order to maintain a constant beam current and fill pattern. During top-up the storage ring current is held within a window of approximately 1.5mA around the target current, generally 250mA, for a variety of fill patterns, including a two-thirds storage ring fill and a hybrid fill in which an intense single bunch is added to the normal fill pattern. Top-up has run continuously for several days on many occasions, with injection efficiency into the storage ring of typically 60%-95% even with 10 in-vacuum insertion device in operation with a permitted minimum gap of 5 mm. The effect of insertion devices, pulsed magnet stability and storage ring beam optics on top-up reliability and performance is examined, and the development of tools for the control of top-up and storage ring fill is detailed.

• J.N. Corlett, K.M. Baptiste, J.M. Byrd, P. Denes, R.W. Falcone, J. Feng, J. Kirz, D. Li, H.A. Padmore, C. F. Papadopoulos, G. Penn, J. Qiang, D. Robin, R.D. Ryne, F. Sannibale, R.W. Schoenlein, J.W. Staples, C. Steier, T. Vecchione, M. Venturini, W. Wan, R.P. Wells, R.B. Wilcox, J.S. Wurtele, A. Zholents
  LBNL, Berkeley, California
• A.E. Charman, E. Kur
  UCB, Berkeley, California

Recent reports have identified the scientific requirements for a future soft x-ray light source and a high-repetition-rate FEL facility responsive to them is being studied at LBNL. The facility is based on a CW superconducting linear accelerator with beam supplied by a high-brightness, high-repetition-rate photocathode electron gun, and on an array of FELs to which the beam is distributed, each operating at high repetition rate and with even pulse spacing. Dependent on the experimental requirements, the individual FELs may be configured for either SASE, HGHG, EEHG, or oscillator mode of operation, and will produce high peak and average brightness x-rays with a flexible pulse format ranging from sub-femtoseconds to hundreds of femtoseconds. We are developing a design concept for a 10‐beamline, coherent, soft x‐ray FEL array powered by a 2.5 GeV superconducting accelerator operating with a 1 MHz bunch repetition rate. Electron bunches are fanned out through a spreader, distributing beams to an array of 10 independently configurable FEL beamlines with nominal bunch rates up to 100 kHz. Additionally, one beamline could be configured to operate at higher repetition rate.

• D. Robin, G.C. Pappas, C. Sun
  LBNL, Berkeley, California
• Z.K. Fisher
  MIT, Cambridge, Massachusetts

We have developed computer models for a pulsed-multipole magnet injection scheme for the Advanced Light Source (ALS) at Lawrence Berkeley National Lab. The multipole kicker injection scheme is further shown to be com- patible with the ALS in combination with a magnet lattice that has a low beta-function in the injection straight. Since traditional injection schemes are not compatible with such optimized low beta lattices, implementing the new injection scheme opens up several new possibilities. For instance, the adoption of a low beta lattice can greatly increase brightness due to the better matching of photon and electron beam emittances. This document explains the principles of the injection and the simulations we performed to show that the concept is sound.

• C. Steier, B.J. Bailey, A. Biocca, A. Madur, H. Nishimura, G.J. Portmann, S. Prestemon, D. Robin, S.L. Rossi, F. Sannibale, T. Scarvie, D. Schlueter, W. Wan, L. Yang
  LBNL, Berkeley, California

The Advanced Light Source is one of the earliest 3rd generation light sources. With an active upgrade program it has remained competitive over the years. The latest in a series of upgrades is a lattice upgrade project that was started in 2009. When it will be completed, the ALS will operate with a horizontal emittance of 2.2 nm and an effective emittance of 2.6 nm. Combined with the high current of 500 mA and the small vertical emittance the ALS already operates at this upgrade will keep it competitive for years to come. The presentation will present the status of the upgrade, including beam dynamics studies and lattice optimizations as well as the magnet design and status.

• Y.K. Wu
  FEL/Duke University, Durham, North Carolina

The light source research program at the Duke Free-Electron Laser Laboratory (DFELL) is focused on the development of accelerator-driven light sources, including storage ring based free-electron lasers (FELs) and Compton gamma-ray source, the High Intensity Gamma-ray Source (HIGS). The HIGS is the most intense Compton gamma-ray source currently available with an energy tuning range from 1 to 100 MeV. The accelerator physics program at the DFELL covers a wide range of activities, from nonlinear dynamics research, to the study of beam instability with advanced feedback systems, to FEL research and development. In this paper, we will report our recent progress in accelerator physics research and light source development to meet new challenges of today's and future accelerators.

• F.A. Laham
  Cornell University, Ithaca, New York
• G.H. Hoffstaetter, C.E. Mayes, J.R. Thompson
  CLASSE, Ithaca, New York

The proposed Cornell Energy Recovery Linac (ERL) is designed for bunches of 77pC and 100mA whose energy is recovered. However, the ERL linac can also be used for larger bunch charges of reduced average current whose energy does not have to be recovered. The proposed Cornell ERL lightsource currently uses a split linac arrangement connected by a turnaround arc. In order to avoid the detrimental effects of Coherent Synchrotron Radiation (CSR) in this arc, a high charge (1nC) bunch must remain relatively long (2ps), and be compressed at high energy (5GeV). An appropriate bunch compressor must take second order effects into account, which adds complications for the large energy spread associated with compression to 100fs or less. We have therefore designed a very simple four dipole bunch compressor at high energy, which uses second order time of flight terms in the turnaround arc rather than in the bunch compressor itself. This design is tested using particle tracking simulations incorporating CSR, as well as magnetic field errors and misalignments.

• Y. Nosochkov, Y. Cai, M.-H. Wang
  SLAC, Menlo Park, California

Design of PEP-X high brightness light source machine is under development at SLAC. The PEP-X is a proposed replacement of the PEP-II in the existing 2.2 km tunnel. Two of the PEP-X six arcs contain DBA type lattice providing 30 dispersion free straights suitable for 3.5 m long undulators. The lattice contains TME cells in the other four arcs and a 90 m wiggler in a long straight section yielding an ultra low horizontal emittance of ~0.1 nm-rad at 4.5 GeV for a high brightness. The recent lattice modifications further increase the predicted brightness and improve beam dynamic properties. The standard DBA cells are modified into supercells for providing low beta undulator straights. The DBA and TME lattice parameters are better optimized. Harmonic sextupoles are added into the DBA arcs to minimize the sextupole driven resonance effects and amplitude dependent tune shift. Finally, the injection scheme is changed from vertical to horizontal plane in order to avoid large vertical amplitudes of injected beam within small vertical aperture of undulators.

• Y. Cai, K.L.F. Bane, K.J. Bertsche, A. Chao, R.O. Hettel, X. Huang, Z. Huang, C.-K. Ng, Y. Nosochkov, A. Novokhatski, T. Rabedeau, J.A. Safranek, G.V. Stupakov, L. Wang, M.-H. Wang, L. Xiao
  SLAC, Menlo Park, California

Over the past year, we have worked out a baseline design for PEP-X, as an ultra-low emittance storage ring that could reside in the existing 2.2-km PEP-II tunnel. The design features a hybrid lattice with double bend achromat cells in two arcs and theoretical minimum emittance cells in the remaining four arcs. Damping wigglers reduce the horizontal emittance to 86 pm-rad at zero current for a 4.5 GeV electron beam. At a design current of 1.5 A, the horizontal emittance increases, due to intra-beam scattering, to 164 pm-rad when the vertical emittance is maintained at a diffraction limited 8 pm-rad. The baseline design will produce photon beams achieving a brightness of 10²² (ph/s/mm²/mrad²/0.1% BW) at 10 keV in a 3.5-m conventional planar undulator. Our study shows that an optimized lattice has adequate dynamic aperture, while accommodating a conventional off-axis injection system. In this paper, we will present the study of the lattice properties, nonlinear dynamics, intra-beam scattering and Touschek lifetime, and collective instabilities. Finally, we discuss the possibility of partial lasing at soft X-ray wavelengths using a long undulator in a straight section.

• S. Park, W.J. Corbett
  SLAC, Menlo Park, California

The recent progress at the SPEAR3 were the increase in stored current from 100 mA to 200 mA maximum and the top-off injection to allow beamlines to stay open during injection. Presently the booster injects 3.0 GeV beam to SPEAR3 three times a day. The stored beam decays to about 150 mA between the injections. The growing user demands are to increase stored current to the design value of 500 mA, and to maintain it at a constant value within a percent or so. To achieve this goal the booster must inject once every few minutes. For improved injection efficiency, all RF systems at the linac, booster and SPEAR3 need to be phase-locked. These requirements entail a booster RF system upgrade to a scaled down version of the SPEAR3 RF system running at 476.3 MHz with a 1.2 MW cw output power capability. The present booster RF system is basically a copy of the SPEAR2 RF system operating at 358.5 MHz with 80 kW peak power to a 5-cell RF cavity for 1.2 MV gap voltage. We will analyze each subsystem option for their merits within budgetary and geometric space constraints. A substantial portion of the system will come from the decommissioned PEP-II RF stations.

• W. Guo, S. Krinsky, L. Yang
  BNL, Upton, Long Island, New York

Chromaticity is usually set to non-zero value at the third generation light sources to cure the intensity induced instabilities. It is effective in suppressing the beam centroid oscillation; however, it is repeatedly reported that the beam lifetime decreases significantly when chromaticity goes up. This is probably due to the crossing of resonance lines by the enlarged tune footprint. In this paper we optimize the NSLS-II lattice at different positive chromaticity settings. The tune footprint is adjusted to fit in the stable region divided by the strong resonance lines. Tracking results show that we can maintain a lifetime similar to that of the zero-chromaticity lattice solutions.

• W. Guo, S.L. Kramer, S. Krinsky, B. Nash, J. Skarita, F.J. Willeke
  BNL, Upton, Long Island, New York

NSLS-II is a third-generation light source that is being built at the Brookhaven National Laboratory. The storage ring has 30 double-bend-achromatic cells. Six 3.5-m-long damping wigglers (DW) will be installed in three straight section to lower the emittance. The civil construction of the facility started in June 2009 and major accelerator components, such as magnets and vacuum chambers, have entered production phase. This paper will summarize the physics considerations for the NSLS-II magnet specifications. In particular, we discuss the tuning range required by the lattice flexibility, and the issues which lead to the specification for the higher-order multipoles.

• Y. Kawashima, J. Cupolo, H. Ma, J. Oliva, J. Rose, R. Sikora, M. Yeddulla
  BNL, Upton, Long Island, New York

The booster synchrotron for NSLS-II accepts beam with 200 MeV from a linac and raises its energy up to 3 GeV. In order to raise beam energy up to 3 GeV, a 7-cell PETRA cavity is installed. Beam instabilities related with the cavity are discussed. In particular, in order to avoid coupled-bunch instability, we consider that cooling water temperature for the cavity should be changed to shift frequencies of higher order modes (HOM) to avoid beam revolution lines. To obtain the relation between the temperature dependence of amount of frequency shift in each HOM and cavity body temperature, we carried out the measurement by changing cavity body temperature. From the measurement data, we calculate the required temperature variation. We summarize the results and describe the system design.

• T.V. Shaftan, A. Blednykh, W.R. Casey, L.R. Dalesio, R. Faussete, M.J. Ferreira, R.P. Fliller, G.S. Fries, G. Ganetis, W. Guo, R. Heese, H.-C. Hseuh, Y. Hu, P.K. Job, E.D. Johnson, Y. Kawashima, B.N. Kosciuk, S. Kowalski, S. Krinsky, Y. Li, H. Ma, R. Meier, S. Ozaki, D. Padrazo, B. Parker, I. Pinayev, M. Rehak, J. Rose, S. Sharma, O. Singh, P. Singh, J. Skaritka, C.J. Spataro, G.M. Wang, F.J. Willeke, L.-H. Yu
  BNL, Upton, Long Island, New York

We discuss status and plans of development of the NSLS-II injector. The injector consists of 200 MeV linac, 3-GeV booster, transport lines and injection straight section. The system design is now nearly completed and the injector development is in the procurement phase. The injector commissioning is planned to take place in 2012.

• N. Malitsky, I. Pinayev
  BNL, Upton, Long Island, New York
• R.M. Talman
  CLASSE, Ithaca, New York
• C. Xiaomeng
  Stony Brook University, Stony Brook

Model Independent Analysis (MIA) is an essential approach for measuring optical properties of accelerators. In the paper, we evaluate its application in the context of the NSLS-II Light Source storage ring. It is the first application of the new high-level application environment based on the EPICS-DDS middle layer. Using a full-scale virtual accelerator, the paper explores the tolerance of the MIA approach against the different conditions such as measurement noise in the beam position monitors, magnet errors, misalignments, etc.

• G.M. Wang, R.P. Fliller, W. Guo, R. Heese, T.V. Shaftan, L.-H. Yu
  BNL, Upton, Long Island, New York
• Y.-C. Chao
  TRIUMF, Vancouver

The low beam emittance requirement in the NSLS-II storage ring imposes a very tight constraint on its acceptance. This requires the injected beam emittance to be very small, for which a reliable scheme of measurement to determine the phase space and momentum characteristics of the beam coming out the booster is necessary. The original scheme based on the booster-to-dump transport line was hampered by the difficulty in decoupling betatron oscillation from dispersion, due to high concentration of dipoles and limited number of quads after the booster. This paper will describe the alternative method being planned to use the booster extraction line to measure the beam emittance and energy spread, as well as the associated errors.