| Paper | Title | Page |
|---|---|---|
| THPC149 | Development of PrFeB Cryogenic Undulator (CPMU) at SOLEIL | 3233 |
|
||
| 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 | 3236 |
|
||
| 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 | 3239 |
|
||
| 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 IDBuilder 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 | 3242 |
|
||
| 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 | 3245 |
|
||
| 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 | 3248 |
|
||
| 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 | 3251 |
|
||
| 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 betaxmin=15 m and betaymin=4.5 m and a low beta straight with betaxmin=betaymin=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 | 3254 |
|
||
| 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 | 3257 |
|
||
| 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 | 3260 |
|
||
| 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. | ||
| THPC159 | Factory Acceptance Test of COLDDIAG: A Cold Vacuum Chamber for Diagnostics | 3263 |
|
||
| Superconductive insertion devices (IDs) have higher fields for a given gap and period length compared with the state-of-the-art technology of permanent magnet IDs. One of the still open issues for the development of superconductive insertion devices is the understanding of the heat intake from the electron beam. With the aim of measuring the beam heat load to a cold bore and the hope to gain a deeper understanding in the underlying mechanisms, a cold vacuum chamber for diagnostics was built. It is equipped with the following instrumentation: retarding field analyzers to measure the electron flux, temperature sensors to measure the beam heat load, pressure gauges, and mass spectrometers to measure the gas content. The flexibility of the engineering design will allow the installation of the cryostat in different synchrotron light sources. The installation in the storage ring of the Diamond Light Source is foreseen in November 2011. Here we report about the technical design of this device, the factory acceptance test and the planned measurements with electron beam. | ||
| THPC160 | A Superconducting Switch for Insertion Devices with Variable Period Length | 3266 |
|
||
| 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 | 3269 |
|
||
| 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 | 3272 |
|
||
| 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 | 3275 |
|
||
| 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 | 3278 |
|
||
| 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 | 3281 |
|
||
| 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 | 3284 |
|
||
| 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 | 3287 |
|
||
|
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 | 3290 |
|
||
| 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 | 3293 |
|
||
|
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 | 3296 |
|
||
| 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 | 3299 |
|
||
| 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. | ||
| THPC172 | Superconducting 119-pole Wiggler for ALBA Light Source | 3302 |
|
||
| Budker INP of Siberian Branch of the Russian Academy of Science has designed, manufactured and tested 119-pole superconducting wiggler for ALBA CELLS light source. The period length and maximal field of the wiggler are 30 mm 2.2 Ò correspondingly. Pole gap and vertical aperture for electron beam are 12.6 mm and 8.5 mm, accordingly. The wiggler magnetic structure closely comes nearer to undulator structure as K-value is about 6. The wiggler cryostat is bath cryostat type with use of cryocoolers which provide zero liquid helium consumption for long period. In June, 2010 the wiggler has been successfully tested on ALBA site. Test results of the wiggler including magnetic measurement, quench training, cryogenic system behavior for various mode of operation are presented. | ||
| THPC173 | Modelization of Inhomogeneities in Permanent Magnet Blocks | 3305 |
|
||
| 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 | 3308 |
|
||
|
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 | 3311 |
|
||
| 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 | 3314 |
|
||
| 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 | 3317 |
|
||
| 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 | 3320 |
|
||
| 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 | 3323 |
|
||
| 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 | 3326 |
|
||
|
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 | 3329 |
|
||
| 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 | 3332 |
|
||
|
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. |
||