In-vacuum Undulator Research Articles

The performance optimization for two in-vacuum undulators in SSRF

The performance optimization for two in-vacuum undulators in SSRF

Delta undulator model: Magnetic field and beam test results

Abstract A novel type of in-vacuum Elliptical Polarization Undulator (EPU) magnet optimized for linac beam (Delta undulator) was developed at the Laboratory for Elementary-Particle Physics (LEPP) at Cornell University as part of insertion device development for the future Cornell 5 GeV Energy Recovery Source of coherent hard X-rays [1,7]. To evaluate mechanical, vacuum and magnetic properties of the magnet, a short 30 cm model with a 5 mm diameter round gap and a 2.4 cm period was built and tested in LEPP. The beam test of the Delta undulator model was conducted at Accelerator Test Facility (ATF) in BNL with ∼60 MeV linac beam. The beam testing results confirmed basic properties of the undulator magnet obtained through the magnetic field measurement. In the paper we describe the magnet design, techniques and setups used for the magnetic field measurement and the beam testing results.

Front-end design of National Synchrotron Light Source II

National Synchrotron Light Source II (NSLS-II) will be a 3-GeV, 792-m circumference third-generation synchrotron radiation facility with ultralow emittance and extremely high brightness. Front ends are required to transmit synchrotron radiation from the storage ring to the beam line while providing equipment and personnel protection. There will be up to 57 front ends in the NSLS-II facility with six in the baseline. Original designs are being developed and will be manufactured for three non-canted in-vacuum undulators, one canted in-vacuum undulator, one elliptically polarized undulator and one damping wiggler. Bending magnet and three-pole wiggler front ends are also being designed. Power densities range from 0.3 to 89.8 kW mrad−2, with total powers ranging from 0.34 to 64.5 kW. All components intercepting synchrotron radiation are water cooled and were analysed to confirm acceptable thermal limits.

Mechanical design and analysis of in-vacuum undulators at the Shanghai Synchrotron Radiation Facility

Two in-vacuum undulators (IVU25) have been used since March 2009 at the Shanghai Synchrotron Radiation Facility. Another small-gap in-vacuum undulator with a smaller period length of 20 mm was completed in July 2010. The mechanical system of IVU25 consists of support frame, driving and guiding system, taper mechanism, compensation spring system, suspending rods assembly, etc. We have attempted to manufacture IVU25 with high mechanical stability, rigidity and reproducible gap motion. A mechanical design study of IVU25 is carried out which includes finite-element calculations on the mechanical deformation of the girder. Some modifications have been made to the design of IVU20.

The controller for Shanghai Synchrotron Radiation Facility in-vacuum undulators

The in-vacuum undulator (IVU) controller has been developed and applied in Shanghai Synchrotron Radiation Facility (SSRF), China. The controller based on programmable logic controller (PLC) mainly controls two stepper motors for regulating the gap and taper of magnet array, implement automatic control of the correction coil power supplies, etc. In addition, the controller is also provided with a local and remote working mode. This paper mainly introduces related hardware and software design for the IVU controller.

ChemInform Abstract: SPring‐8 Structural Biology Beamline

AbstractReview: 13 refs.

SSRF Phase-I Insertion Devices

Shanghai Light Source (SSRF) is a third generation synchrotron radiation facility with the intermediate energy of 3.5 GeV. Two wigglers W80 and W140, one elliptically polarizing undulator EPU100 of the APPLE-II type with 4.3 meters long and two in-vacuum undulators IVU25-1,2 with 2 meters long have been built in the phase-I of SSRF project. This paper describes the design parameters, the magnet configurations and the magnetic field performances of these five IDs. The electron trajectories, the phase errors and the predicated on-axis spectral fluxes with the measured magnetic fields of two in-vacuum undulators are also presented. The R.M.S. phase errors of less than 4 are obtained for the EPU100 in the horizontal polarization mode as well as in the vertical polarization mode. The maximum R.M.S. phase errors for two in-vacuum undulators are 3.1 and 2.2° respectively and the ratio of the photon flux to the ideal case is larger than 80% on the 11th harmonic.

SPring-8 Structural Biology Beamline

Nowadays, three-dimensional structure of protein becomes important to understanding and application of molecular mechanisms in enzyme reaction, signal transduction and other various biochemical processes. The amount of the information is now growing quantitatively and qualitatively, supported in part by the technical development of macromolecular crystallography. In the development, brilliant synchrotron radiation greatly contributes to enhance the accuracy and precision of diffraction data and the throughput of data collection. At SPring-8, JASRI and RIKEN collaborate to utilize the macromolecular crystallography beamlines and actualize these improvements. High throughput and routine analysis of protein structures is achieved by the development of automation system composed of sample exchange robotics and control software. The remote data collection system using the automation system and internet technology enhances efficiency and convenience of the beamlines. Moreover, the development of a rapid-readout complementary metal oxide semiconductor (CMOS) detector will improve throughput in data collection. On the other hand, data collection with high accuracy and precision is achieved by the utilization of brilliant X-ray produced from the in-vacuum undulator. Its brightest and stable beam enables high resolution data collection and 10 mum microbeam for microcrystals. Although the high brilliance severely damages protein samples, the users can estimate the degree of the damage and plan best data collection strategy.

Beamline I11 at Diamond: A new instrument for high resolution powder diffraction

The performance characteristics of a new synchrotron x-ray powder diffraction beamline (I11) at the Diamond Light Source are presented. Using an in-vacuum undulator for photon production and deploying simple x-ray optics centered around a double-crystal monochromator and a pair of harmonic rejection mirrors, a high brightness and low bandpass x-ray beam is delivered at the sample. To provide fast data collection, 45 Si(111) analyzing crystals and detectors are installed onto a large and high precision diffractometer. High resolution powder diffraction data from standard reference materials of Si, alpha-quartz, and LaB6 are used to characterize instrumental performance.

In-vacuum Undulators as Japanese Original Synchrotron Radiation Sources

In-vacuum Undulators as Japanese Original Synchrotron Radiation Sources

Development of Vacuum Components for the Project of X-ray Free Electron Laser (XFEL/SPring-8)

Several new vacuum components have been developed for the XFEL/SPring-8 project. Vacuum waveguide flanges were successfully developed. These flanges provide both RF seal and vacuum seal. The vacuum seal mechanism of these flanges can make seal completely even with a deep scratch on the gasket. Solid-lubricated clean bolt and nut were developed for this flange to avoid organic dust pollution in the vacuum that induces RF discharge. A small RF contact for 28 mm inside diameter bellows was developed. This free ends structure RF contact can move freely in all directions and realize large displacement. The vacuum system of in-vacuum type undulator that commonly used in the accelerators is also described briefly.

Investigation of a method to calculate spontaneous radiation spectra from relativistic electrons in undulators

Undulators are key devices to produce brilliant synchrotron radiation at the synchrotron radiation facilities. In this paper we present a numerical computing method, including the computing program that has been developed to calculate the spontaneous radiation emitted from relativistic electrons in undulators by simulating the electrons' trajectory. The effects of electron beam emittance and energy spread have also been taken into account. Comparing with other computing methods available at present, this method has a few advantages with respect to several aspects. It can adopt any measured or arbitrarily simulated 3D magnetic field and arbitrary electron beam pattern for the calculation and it's able to analyze undulators of any type of magnetic structure. It's expected to predict precisely the practical radiation spectrum. The calculation results of a short period in-vacuum undulator and an Elliptically Polarized Undulator (EPU) at Shanghai Synchrotron Radiation Facility (SSRF) are presented as examples.

The High Energy Materials Science Beamline at PETRA III

The future High Energy Materials Science Beamline HEMS at the new German high brilliance synchrotron radiation storage ring PETRA III [1] will have a main energy of 120 keV, will be fully tunable in the range of 50 to 300 keV, and will be optimized for sub-micrometer focusing with Compound Refractive Lenses and Kirkpatrick-Baez Multilayer mirrors. Design and construction is the responsibility of the Research Center Geesthacht, GKSS, with approximately 70 % of the beamtime being dedicated to Materials Research, the rest reserved for “general physics” experiments covered by DESY, Hamburg. Fundamental research will encompass metallurgy, physics and chemistry. For first experiments in investigating grain-grain-interactions a dedicated 3D-microstructure-mapper will be designed. Applied research for manufacturing process optimization will benefit from the high flux in combination with ultra-fast detector systems allowing complex and highly dynamic in-situ studies of microstructural transformations. The beamline infrastructure will allow easy accommodation of large user provided equipment. Experiments targeting the industrial user community will be based on well established techniques with standardised evaluation, allowing "full service" measurements. Environments for strain mapping [2] on large structural components up to 1 t will be provided as well as automated investigations of large numbers of samples, e.g. for tomography and texture determination. The current design for the beamline (P07 in sector 5 of the future experimental hall) consists of a nearly five meter in-vacuum undulator source (U19-5) optimized for high energies, a general optics hutch, an in-house test facility and three independent experimental hutches working alternately, plus additional set-up and storage space for long-term experiments. HEMS should be operational in spring 2009 as one of the first beamlines running at PETRA III.

CMCF 08ID-1 beamline at the Canadian Light Source

The Canadian Macromolecular Crystallography Facility has more than sixty participating protein crystallographers, located across Canada, will eventually consist of three beamlines; two insertion devices beamlines and one bending magnet beamline [1]. The first insertion device beamline (08ID-1) was intended to be a highly efficient and flexible, capable of satisfying the requirements of the most challenging and diverse crystallographic experiments, i.e. physically small crystals with large unit cell dimensions. The recently funded bending magnet 08B1 beamline has been designed to be dedicated to highthroughput data collection capable of being accessed remotely. The third, an undulator based 08ID-2 beamline, is envisioned to have micro-focusing capabilities with some restrictions in energy range. The CMCF 08ID-1 beamline has been built and is now being commissioned. The beamline is illuminated by a small-gap in-vacuum hybrid undulator (SGU), located in the upstream half of the straight section, and chicaned inboard by 0.75 mrad. The downstream half of this section is reserved for the 08ID-2 beamline SGU. The overall design of the beamline contains white beam slits (WBS), a double crystal monochromator (DCM) equipped with an indirectly cryocooled first crystal and a sagittally-focusing second crystal followed by a vertically focussing mirror (VFM). The beamline is completed with an innovative and very robust endstation, including the MarMosaic225 CCD X-ray detector. Most of the beamline components were manufactured by ACCEL Instruments GmbH (Germany). The beamline controls, similarly for the CLS facility, are being developed based on the EPICS platform. The beamline is equipped with a Rontek Spectrometer System (XFLASH 101A) for carrying out X-ray absorption near edge structure spectroscopy (XANES) for multiwavelength anomalous diffraction (MAD) experiments, and X-ray fluorescence (XRF) for the detection of metal atoms in protein derivative crystals. The beamline will be equipped with a robotic cryogenic sample changer that is based on the SSRL design (SAM). At the meeting we will present recent results of experiments performed at the CMCF 08ID-1 beamline. The CLS is supported by NSERC, NRC, CIHR and the University of Saskatchewan..

Canadian Macromolecular Crystallography Facility (CMCF) 08ID-1 status update

The Canadian Macromolecular Crystallography Facility (CMCF) 08ID-1 beamline at the Canadian Light Source (CLS) is in the later stages of commissioning. The photon source is a small-gap in-vacuum undulator (SGU), which was designed in-house with a support structure and vacuum chamber from RMP of Italy. The undulator magnets were shimmed at the CLS and the SGU was installed in the 2.9 GeV storage ring. The storage ring has had currents up to 300 mA safely injected and stored since its first light in the diagnostic beamline in December of 2003. At these storage ring currents, the 7th harmonic of the SGU will yield a photon flux on the sample at the endstation on the order of ∼ 5 × 10 12 at 12 keV. The overall design of the beamline includes white beam slits, indirectly cryo-cooled first crystal of the DCM and sagittally focusing second crystal, and vertically focussing ULE mirror. The endstation of the beamline is innovative and robust, and was manufactured by ACCEL according to CLS specifications. The beamline controls, are being developed based on EPICS, and complemented with a user-friendly interface. The scientific goal of the 08ID-1 beamline is to operate a protein crystallography MAD beamline suitable for studying small crystals and crystals with large unit cells.

Spectral measurements and synchrotron radiation calculation comparisons of the new X25 mini-gap undulator

During January 2006, a new hybrid PM-type in-vacuum mini-gap undulator (MGU) with NdFeB magnets and vanadium permendur poles was installed within the X25 straight-section of the 2.8 GeV National Synchrotron Light Source (NSLS) electron storage ring. This new insertion device was implemented to deliver high brightness X-ray beams within the energy range of ∼5.5–20 keV for monochromatic single-crystal X-ray macromolecular crystallography. The spectral output from such a device is very sensitive to the storage ring machine parameters and in this paper, we report the precise determination of the new X25 MGU performance by implementing a single-crystal silicon (1 1 1) X-ray spectrometer to measure the X-ray energy-dependent flux throughput and infer the corresponding brightness values for a wide range of undulator gap openings. We compare these values to synchrotron radiation calculations using the SPECTRA (version 8.0) code and confirm both the integrity of the new X25 MGU device and the emittance values of the NSLS electron storage ring.

First SOLEIL insertion devices are ready to produce photons for users

SOLEIL is the French 2.75 GeV synchrotron radiation light source of low emittance under construction near Paris. It will provide high intensity photons covering a wide spectral range from the IR to the hard X-rays. The storage ring commissioning started in late May 2006, and the first photons on the first beamline were observed in September 2006. The first set of Insertion Devices (ID), either already installed before the ring commissioning or to be installed within the first year of operation of the machine, consists of one 640 mm period and three 256 mm period electromagnetic elliptical undulators, three 80 mm period APPLE-II type undulators, and three 20 mm period in-vacuum undulators. All these IDs make use of a wide panoply of technical solutions for generating various types of magnetic fields. Magnetic and conceptual designs were performed by SOLEIL, and the technical realization was carried out together with different manufacturers. The design specificities of the different types of IDs, as well as the results of the shimming and magnetic measurements performed at SOLEIL are reported.

Electron optics of a future SC ERL at KAERI

A project of a high-power FEL at Korea Atomic Energy Research Institute is described. The FEL is driven by a superconducting energy recovery linac. The future ERL will be connected to the existing machine without any modification. It consists of two 180° bents and two straight sections: one is for the FEL, another for a Compton X-ray source. One can choose the regime controlling the lenses. The total ERL is isochronous to avoid any problem with longitudinal beam instability. The total relative emittance degradation through the whole machine is ≈1.5. The FEL will be based on a 2 m helical in-vacuum undulator made of permanent magnets. One mirror of the optical cavity is blind and made of copper, the other one, the outcoupler, is semi-transparent and made of CVD diamond. The expected average power is a few kW, the tuning range 35–70 μm.

Synchrotron radiation x-ray beam profile monitor using chemical vapor deposition diamond film

Photoluminescence (PL) of a Si-doped polycrystalline diamond film fabricated using the chemical vapor deposition technique was employed to measure the profile of a synchrotron radiation pink x-ray beam emitted from an in-vacuum hybrid undulator at the SPring-8 facility. The spectrum of the section of the diamond film penetrated by the emitted visible red light exhibited a peak at 739nm and a wideband structure extending from 550to700nm. The PL intensity increased with the absorbed dose of the incident beam in the diamond within a dynamic range of 103. A two-dimensional distribution of the PL intensity revealed the undulator beam profile.

Complete automation of molecular replacement

Diamond [1] is the new third generation synchrotron source which is currently being built in the United Kingdom south of Oxford. In Phase 1 seven beamlines are funded which includes three beamlines for macromolecular crystallography (MX). Radiation from three in-vacuum undulators will be used for these beamlines. The undulators will be canted to allow for a second one to be placed in the straight to provide radiation for a side station. All three MX beamlines will be tunable over a wavelength range of 0.5-2.5 A to allow for multiple anomalous dispersion experiments. Significant emphasis is being placed on the automation of each beamline, both in terms of hardware and software. The implemented diagnostics tools will also allow for a remote monitoring and control of the beam. The experimental stations will be equipped with large area detectors, with robotic sample changers to enable automatic mounting of cryocooled and room temperature samples as well as a high quality crystal viewing system. Next to the beamlines the users will find support laboratories to prepare for their experiments. The MX beamlines are scheduled for commissioning in 2006 and will come on-line for users in 2007.