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At least 55 records · Page 3

Data analysis of photon beam position at PLS-II

In the third generation light source, photon beam position stability is critical issue on user experiment. Generally photon beam position monitors have been developed for the detection of the real photon beam position and the position is controlled by feedback system in order to keep the reference photon beam position. In the PLS-II, photon beam position stability for front end of particular beam line, in which photon beam position monitor is installed, has been obtained less than rms 1μm for user service period. Nevertheless, detail analysis for photon beam position data in order to demonstrate the performance of photon beam position monitor is necessary, since it can be suffers from various unknown noises. (for instance, a back ground contamination due to upstream or downstream dipole radiation, undulator gap dependence, etc.) In this paper, we will describe the start to end study for photon beam position stability and the Singular Value Decomposition (SVD) analysis to demonstrate the reliability on photon beam position data.

43 PARTICLE ACCELERATORS↗

Project to renew the undulators at the photon factory

At the 2.5-GeV Photon Factory (PF) storage ring, we recently constructed four new undulators known as U#02-2, U#13, SGU#15, and U#28 for BL02, BL13, BL15, and BL28, respectively. SGU#15 is an in-vacuum undulator with a period length of 17.6 mm. The other three undulators are elliptically polarizing undulators (EPUs) for the vacuum ultraviolet and soft X-ray (VUV-SX) light sources to obtain various polarization states. We constructed these new undulators by fiscal 2013 and step by step installed them in the PF ring. We describe the details of the construction of these new undulators in this report.

43 PARTICLE ACCELERATORS↗

Status of the LCLS-II undulators

The new free electron laser facility Linear Coherent Light Source II (LCLS-II) under construction at SLAC National Accelerator Laboratory will use planar variable gap undulators of hybrid type for the production of free electron laser (FEL) radiation. The LCLS-II will include two FELs with two separate rows of undulators to generate soft and hard x-rays. The soft x-rays will be produced by undulators with 39 mm period length (SXR) and the hard x-rays will be produced by undulators with 26 mm period length (HXR). Both the SXR and the HXR undulators are 3.4 m long and they use a common support structure and frame. In total 21 SXR and 32 HXR undulators will be produced by Lawrence Berkeley National Laboratory in collaboration with SLAC National Accelerator Laboratory. A full-scale prototype with 32 mm period length, called HXU, has been assembled at Lawrence Berkeley National Laboratory (LBNL). The present status of the design, prototyping, and pre-series production of the SXR and HXR undulators are presented in this paper together with the first results from measurements on the full scale HXU prototype.

43 PARTICLE ACCELERATORS↗

Progress on the development of the next generation x-ray beam position monitors at the advanced photon source

Accurate and stable x-ray beam position monitors (XBPMs) are key elements in obtaining the desired user beam stability in the Advanced Photon Source (APS). The next generation XBPMs for high heat load front ends (HHL FEs) have been designed to meet these requirements by utilizing Cu K-edge x-ray fluorescence (XRF) from a pair of copper absorbers and have been installed at the front ends (FEs) of the APS. Commissioning data showed a significant performance improvement over the existing photoemission-based XBPMs. While a similar design concept can be applied for the canted undulator front ends, where two undulator beams are separated by 1.0-mrad, the lower beam power (< 10 kW) per undulator allows us to explore lower-cost solutions based on Compton scattering from the diamond blades placed edge-on to the x-ray beam. A prototype of the Compton scattering XBPM system was installed at 24-ID-A in May 2015. In this report, the design and test results for XRF-based XBPM and Compton scattering based XBPM are presented. Ongoing research related to the development of the next generation XBPMs on thermal contact resistance of a joint between two solid bodies is also discussed.

43 PARTICLE ACCELERATORS↗

Beamline front end for in-vacuum short period undulator at the photon factory storage ring

The straight-section upgrade project of the Photon Factory created four new short straight sections capable of housing in-vacuum short period undulators. The first to fourth short period undulators SGU#17, SGU#03, SGU#01 and SGU#15 were installed at the 2.5-GeV Photon Factory storage ring in 2005, 2006, 2009 and 2013, respectively. The beamline front end for SGU#15 is described in this paper.

43 PARTICLE ACCELERATORS↗

Commissioning of the soft x-ray undulator beamline at the Siam Photon Laboratory

The synchrotron radiation from the first undulator at the Siam Photon Laboratory was characterized with the photon beam position monitors (BPMs) and grating monochromator. The soft x-ray undulator beamline employs a varied line-spacing plane grating monochromator with three interchangeable gratings. Since 2010, the beamline has delivered photons with energy of 40-160 and 220-1040 eV at the resolving power of 10,000 for user services at the two end- stations that utilize the photoemission electron spectroscopy and microscopy techniques. The undulator power-density distributions measured by the 0.05-mm wire-scan BPM were in good agreement with those in simulation. The flux-density distributions were evaluated in the red-shift measurements, which identify the central cone of radiation and its distribution. Since 2014, the operation of the other insertion devices in the storage ring has started, and consequently bought about the increases in the emittance from 41 to 61 nm·rad and the coupling constant from 4 to 11%. The local electron-orbit correction greatly improved the alignment of the electron beam in the undulator section resulting in the improvements of the photon flux and harmonics peaks of the undulator radiation.

43 PARTICLE ACCELERATORS↗

NSLS-II storage ring insertion device and front-end commissioning and operation

The National Synchrotron Light Source II (NSLS-II) is a state of the art 3 GeV third generation light source at Brookhaven National Laboratory. During spring/ summer of 2014, the storage ring was commissioned up to 50 mA without insertion devices. In the fall of 2014, we began commissioning of the project beamlines, which included seven insertion devices on six ID ports. Beamlines IXS, HXN, CSX-1, CSX-2, CHX, SRX, and XPD-1 consist of elliptically polarized undulator (EPU), damping wigglers (DW) and in-vacuum undulators (IVU) covering from VUV to hard x-ray range. In this paper, experience with commissioning and operation is discussed. We focus on reaching storage ring performance with IDs, including injection, design emittance, compensation of orbit distortions caused by ID residual field, source point stability, beam alignment and tools for control, monitoring and protection of the ring chambers from ID radiation.

43 PARTICLE ACCELERATORS↗

Micro- and nano-imaging at the diamond beamline I13L-imaging and coherence

The Diamond Beamline I13L is dedicated to imaging on the micron- and nano-lengthscale, operating in the energy range between 6 and 30 keV. For this purpose two independent stations have been built. The imaging branch is fully operational for micro-tomography and in-line phase contrast imaging with micrometer resolution. Currently a full-field microscope providing 50nm spatial resolution over a field of view of 100 µm is being tested. On the coherence branch, coherent diffraction imaging techniques such as ptychography and coherent X-ray Bragg diffraction are currently developed. The beamline contains a number of unique features. The machine layout has been modified to the so-called mini-beta scheme, providing significantly increased flux from the two canted undulators. New instrumental designs such as a robot arm for the detector in diffraction experiments have been employed. The imaging branch is operated in collaboration with Manchester University, called therefore the Diamond-Manchester Branchline.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DCS - A high flux beamline for time resolved dynamic compression science – Design highlights

The Dynamic Compression Sector (DCS) beamline, a national user facility for time resolved dynamic compression science supported by the National Nuclear Security Administration (NNSA) of the Department of Energy (DOE), has recently completed construction and is being commissioned at Sector 35 of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The beamline consists of a First Optics Enclosure (FOE) and four experimental enclosures. A Kirkpatrick–Baez focusing mirror system with 2.2 mrad incident angles in the FOE delivers pink beam to the experimental stations. A refocusing Kirkpatrick–Baez mirror system is situated in each of the two most downstream enclosures. Experiments can be conducted in either white, monochromatic, pink or monochromatic-reflected beam mode in any of the experimental stations by changing the position of two interlocked components in the FOE. The beamline Radiation Safety System (RSS) components have been designed to handle the continuous beam provided by two in-line revolver undulators with periods of 27 and 30 mm, at closed gap, 150 mA beam current, and passing through a power limiting aperture of 1.5 x 1.0 mm{sup 2}. A novel pink beam end station stop [1] is used to stop the continuous and focused pink beam which can achieve a peak heat flux of 105 kW/mm{sup 2}. A new millisecond shutter design [2] is used to deliver a quick pulse of beam to the sample, synchronized with the dynamic event, the microsecond shutter, and the storage ring clock.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Construction and performance of combustion beamline at NSRL

An undulator-based VUV beamline BL03U is constructed at the National Synchrotron Radiation Laboratory. Optical design and performance test results are presented in this paper. The monochromator is a Czerny–Turner configuration with a toroidal collimating mirror, two plane gratings, and a toroidal focusing mirror. Plane gratings with line densities of 200 and 400 l/mm are used to cover the photon energy range of 5–21 eV. A gas absorption spectrum is used to evaluate the beamline performance. The photon energy resolving power (E/ΔE) of the beamline is approximately 3900 at 7.3 eV for the 200 l/mm grating and 4200 at 14.6 eV for the 400 l/mm grating. The photon flux is approximately 5×10{sup 12} photons/s/300 mA at energy of 10 eV.

43 PARTICLE ACCELERATORS↗

The EMIL project at BESSY II: Beamline design and performance

The Energy Materials In-Situ Laboratory Berlin (EMIL) at BESSY-II is currently under construction. Two canted undulators for soft- and hard X-rays will be installed into the BESSY II storage ring in one straight section, complex beamlines with more than twenty optical elements will be set up and a new laboratory building attached to BESSY II will host three endstations and a large UHV-transfer system connecting various HV- and UHV-deposition systems. The undulators, UE48 and U17, provide a broad energy spectrum of 80 - 10000 eV, of which the harder radiation (>700 eV) is provided by a cryogenic in-vacuum device. Three monochromators (two plane grating monochromators (PGM) and one LN{sub 2}-cooled double crystal monochromator (DCM)) disperse the radiation into separate pathways of 65 m length, while downstream of the monochromators split-mirror chambers distribute the photon beam to one (or simultaneously to two) of five upcoming endstations. Three of these endstations are designed for the full energy range with spatial overlap of the soft and hard foci, whereas one endstation (PEEM) uses only the soft and another one (PINK) only the hard branch, respectively.

43 PARTICLE ACCELERATORS↗

Current status of BL-2B at photon factory

A new soft x-ray beamline BL-2B at Photon Factory of High Energy Accelerator Research Organization (KEK-PF) covers energy range from vacuum ultraviolet (30 eV) to soft x-ray (4000 eV). This wide energy range could be achieved by employing two undulators and two monochromators. Two different energy range undulators were installed tandem to a 9-meter straight section of PF storage ring. The 1{sup st} undulator is for VUV (30 eV) to SX (280 eV), while the other one is for SX (280 eV) to HX (4000 eV). It is also necessary to be equipped with two different monochrometors for energy above and under 2000 eV; grating monochrometor and double crystal monochrometor. One of the main purposes of this bemaline is spectroscopic study of light elements contained in several functional materials. The beamline is designed for photoemission spectroscopy (PES), X-ray absorption fine structure (XAFS) and other types of experiments. The performance of the new beamline is reported and typical examples of its application to material science are demonstrated.

43 PARTICLE ACCELERATORS↗

Low energy soft x-ray emission spectrometer at BL-09A in NewSUBARU

A compact soft X-ray emission spectrometer for the energy region of 50-600 eV has been designed and constructed for the long undulator beamline BL-09A in the NewSUBARU synchrotron radiation (SR) facility. The optical design of the spectrometer is based on a grazing incidence flat-field spectrometer using a valid line-spacing grating. The average groove density of the grating is 2000 L/mm, and the angle of incidence to the grating is 86.5 deg. The distances from the slit to the grating and from the grating to the CCD are 355 mm and 650 mm, respectively. The energy resolution, E/ΔE, was estimated to be greater than 1000 in the energy range of 50-600 eV. Spectra of K-emission X-rays of several light elements, such as B, C, N, and O, from various samples were successfully obtained.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Toyota beamline (BL33XU) at SPring-8

The Toyota beamline (BL33XU) at SPring-8 is an undulator beamline developed to assist in the study of various automotive-related materials. The light source is a tapered in-vacuum undulator that provides a variable energy band width as well as a high brilliance X-ray beam. Two different optical arrangements are available: Optics 1 and Optics 2. Optics 1 is dedicated to time-resolved X-ray absorption spectroscopy (XAFS), and consists of two channel-cut crystal monochromators and four water-cooled flat Si mirrors. The Si(111) and Si(220) monochromator crystals cover an energy range of 4.0–46.0 keV and are driven by high-speed AC servo motors. These monochromators, in conjunction with the tapered undulator, enable high-quality XAFS data acquisition with a temporal resolution of 10 ms. Optics 2 is optimized for X-ray diffraction, scattering and imaging and includes a recently installed double crystal monochromator, two water-cooled flat Si mirrors and Kirkpatrick-Baez (KB) focusing mirrors. The monochromator incorporates parallel mounted Si(111) and Si(311) crystals and covers an energy range of 4.5–70 keV. The beamline provides two experimental stations: Exp. Hutch 2 and Exp. Hutch 3. The gas supply system and mass spectrometers installed in Exp. Hutch 2 allow in-operando measurements under various atmospheres. The scanning three-dimensional X-ray diffraction (scanning 3DXRD) microscopy instrumentation developed and installed in Exp. Hutch 3 enables non-destructive orientation and stress mapping of 1 mm-thick steel specimens using a high energy microbeam.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Soft x-ray spectromicroscopy using compact scanning transmission x-ray microscope at the photon factory

We report the stability and recent performances of a new type of scanning transmission X-ray microscopy. The optics and compact design of the microscope realized mobility and robust performance. Detailed consideration to the vibration control will be described. The insertion device upgraded to elliptical polarization undulator enabled linear dichroism and circular dichroism experiments.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Initial performances of first undulator-based hard x-ray beamlines of NSLS-II compared to simulations

Commissioning of the first X-ray beamlines of NSLS-II included detailed measurements of spectral and spatial distributions of the radiation at different locations of the beamlines, from front-ends to sample positions. Additionally, comparison of some of these measurement results with high-accuracy calculations of synchrotron (undulator) emission and wavefront propagation through X-ray transport optics, performed using SRW code, is presented.

47 OTHER INSTRUMENTATION↗

Newly designed double surface bimorph mirror for BL-15A of the photon factory

BL-15A is a new x-ray undulator beamline at the Photon Factory. It will be dedicated to two independent research activities, simultaneous XAFS/XRF/XRD experiments, and SAXS/WAXS/GI-SAXS studies. In order to supply a choice of micro-focus, low-divergence and collimated beams, a double surface bimorph mirror was recently developed. To achieve further mirror surface optimization, the pencil beam scanning method was applied for “in-situ” beam inspection and the Inverse Matrix method was used for determination of optimal voltages on the piezoelectric actuators. The corrected beam profiles at every focal spot gave good agreement with the theoretical values and the resultant beam performance is promising for both techniques. Quick and stable switching between highly focused and intense collimated beams was established using this new mirror with the simple motorized stages.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

High-heat-load monochromator options for the RIXS beamline at the APS with the MBA lattice

With the MBA lattice for APS-Upgrade, tuning curves of 2.6 cm period undulators meet the source requirements for the RIXS beamline. The high-heat-load monochromator (HHLM) is the first optical white beam component. There are four options for the HHLM such as diamond monochromators with refrigerant of either water or liquid nitrogen (LN{sub 2}), and silicon monochromators of either direct or indirect cooling system. Their performances are evaluated at energy 11.215 keV (Ir L-III edge). The cryo-cooled diamond monochromator has similar performance as the water-cooled diamond monochromator because GaIn of the Cu-GaIn-diamond interface becomes solid. The cryo-cooled silicon monochromators perform better, not only in terms of surface slope error due to thermal deformation, but also in terms of thermal capacity.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗