SLAC, Menlo Park, California
A new method, using the parabolic equation (PE), for the calculation of both high-frequency and small-angle taper (or collimator) impedances is developed in [1]. One of the most important advantages of the PE approach is that it eliminates the spatial scale of the small wavelength from the problem. As a result, the numerical solution of the PE requires coarser spatial meshes. We developed a new code based on Finite Element Method (FEM) which can handle arbitrary profile of a transition. As a first step, we completed and benchmarked a two-dimensional code. One of the important advantages of the code is its fast execution time.
PAL, Pohang, Kyungbuk
In 1994, ESRF in Grenoble opened the era of third-generation light sources, and the first batch of third-generation machines immediately followed with ALS, Elettra, TLS, PLS, and Spring-8 in hard and soft X-ray regimes. For high brightness, these machines adopted a low-emittance storage-ring lattice and many straight sections for advanced undulators. With ever-growing user demands from materials science to life science research, many more facilities followed in this decade. The machine operations dramatically improved for more effective user services, along with technological advances in advanced diagnostics and controls, survey and alignments, top-up injections, super-conducting cavities, and in-vacuum undulators. There are now about 70 light sources in the world, and important scientific discoveries are driven from these facilities, including research resulting in a few Nobel Prizes. In this paper, we review the advancement of these third-generation machines.
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.
CLS, Saskatoon, Saskatchewan
The Canadian Lightsource is a 2.9 GeV 3rd generation lightsource in Saskatoon, Canada. The latest expansion of operations includes adding 4 insertion devices in 2 straight sections. These devices will include a hybrid permanent magnet wiggler, an in-vacuum undulator and 2 APPLE-II type undulators. The 4 m long elliptical APPLE-II IDs will cover overlapping photon energy ranges of 15-200eV and 200-1000eV. These devices will be installed adjacent to one another in the same straight with the magnet arrays mounted on one support structure and a horizontal translation system to allow users to select one device at a time for use on a single beamline. The 2nd straight will include the hybrid wiggler and in-vacuum undulator in a 3 magnet chicane. The wiggler is designed to supply photons for a center beamline and a side beamline accepting radiation 5 mrad off of the centerline of the radiation fan. The critical energy of photons emitted of the sideline are >90% of the critical energy on the centerline. An 8 mrad center chicane magnet separates the photons of the undulator from the wiggler beamlines allowing for 3 beamlines operating with 2 IDs in a single straight section.
NSRRC, Hsinchu
An elliptically polarized undulator of length 3.5 m and period length 48 mm (EPU48) is designed to fulfil experiments on spin-polarized PES and inelastic scattering at the Taiwan Photon Source (TPS). EPU48 would be used to produce variously polarized light in the soft X-ray spectral domain 0.4-1.5 keV. To achieve efficient mechanical performance and a high quality of photon source, a new manufacturing method by casting is adopted to fabricate a key component of the carriage of the undulator at National Synchrotron Radiation Research Center (NSRRC). We expect this approach to bestow advantages of decreased assembly error, increased rigidity and highly precise properties. Here we describe details of the design of the magnetic circuit and the mechanical design of the EPU48 based on this new concept of engineering construction.
Kyungpook National University, Daegu
Pohang Light Source-Ⅱ (PLS-Ⅱ) is an upgrade project of the existing 2.5 GeV PLS. The circumference, beam current and energy of PLS-Ⅱ storage ring are 281.82 m, 400 mA and 3 GeV, respectively. The upgrade project has many issues on beam dynamics. We investigated lattice optimization such as lattice corrections, dynamic aperture, selection of optimized tune & emittance and effects of insertion devices. MAD, SAD and Elegant have been used to the lattice optimization. We investigated the effects of machine errors and 20 IDs to the dynamic aperture. PLS-Ⅱ lattice include twenty insertion devices and their effects on the beam dynamics are investigated. We also investigate possibility to reduce the emittance by increasing horizontal betatron tune and adjusting the dispersion by using of MAD, SAD and Elegant and also examined the required strengths of sextupoles for the various emittances.
NSRRC, Hsinchu
In this paper, the simulation techniques of insertion device (ID) were discussed. Piecewise hard-edge model was used to estimate the tune shift and changes of emittance and energy spread, while kick map model was used for particle tracking. Optical functions and tune shifts can also be derived by this model. Frequency maps as well as the beta-beating and its correction of Phase I IDs are demonstrated.
SOLEIL, Gif-sur-Yvette
SOLEIL, the French 2.75 GeV high brilliance third generation synchrotron light source is delivering photons to 20 beam lines and is presently equipped with 17 insertion devices. Significant reduction of injection efficiency and beam lifetime are observed when using some undulator configurations in daily operation. Measurements on electron beam, such as beam lifetime versus RF voltage, have shown that the energy acceptance is strongly reduced by the combined non linear effects of the four U20 in-vacuum undulators and the HU640 10m long undulator used in linear vertical polarization mode. This paper will present the on and off momentum frequency map measurements that have been performed in order to investigate such effects. The reduction of the on momentum dynamic aperture in the presence of the U20 undulators is confirmed. The off momentum frequency map measurements confirm that the energy acceptance of the bare machine is very large as predicted by tracking calculations, and clearly exhibit the strong energy acceptance reduction due to undulators.
CELLS-ALBA Synchrotron, Cerdanyola del Vallès
The synchrotron light source ALBA incorporates 6 insertion devices (2 Apple-II type undulators, 2 plannar in-vacuum undulators, 1 normal conducting multipole wiggler and 1 superconduction multipole wiggler) at the start of operation. The effect of the different IDs in the performance of the facility is evaluated, using several methods (kick maps, hard edge models, dynamic multipoles, …), including a comparison of the agreement of the different models and simulation codes. According to the results, and due mainly to the influence of the superconducting wiggler, a new working point has been selected.