Girder integration NSLS-II

National Synchrotron Light Source II (NSLS-II) will be a 3-GeV 792 m circumference third generation synchrotron radiation facility with ultra low emittance and extremely high brightness. There will be a total of 90 multipole storage ring girders supporting the vacuum chambers, multipole magnets and various pieces of ancillary equipment. A major effort is being made to meet the stringent assembly and alignment requirements for the girder assemblies using relatively few and removable positioning fixtures. Girder assembly and alignment will be accomplished in four phases. Each of these phases will be described along with the fixtures required.

Design concept for a modular in-vacuum Hall probe mapper for in-vacuum undulators and cryogenic permanent magnet undulators of varying magnetic length

Both in-vacuum undulators (IVUs) and cryogenic permanent magnet undulators (CPMUs), each important to third-generation light sources, are best characterized in their operating environment. To create a precision Hall probe map of an IVU/CPMU (IVU hereafter), an in-vacuum magnetic measurement (IVMM) system is proposed. Point-by-point measurement of field and trajectory error informs corrective tuning.A novel design concept for a universal IVMM System has been developed and explored. The IVMM seals to the rectangular Ultra High Vacuum (UHV) flange of the IVU and shares its common vacuum space. Moreover, a modular design permits a wide range of IVUs of varying magnetic length to be mapped with a single IVMM, and is thus cost effective when multiple IVUs of varying configurations are planned. Here we review aspects of the modular IVMM design concept.

SWING detection vacuum tunnel

The SWING beamline is dedicated to the study of the small-angle X-ray scattering. In order to have the possibility to detect scattered intensity very close to the incident beam, it is absolutely necessary to install the detector at a long distance from the sample. In addition, it is easy to change the detector's position to access a wider angular range. A long and large vacuum chamber, the ‘tunnel’, has been designed with specific mechanisms inside to control the detector's position with micrometre resolution. Special attention has been given so as to offer a very useful device to the users. The paper will present the general design of the tunnel equipped with ancillary devices such as very narrow and stiff beam stoppers, diode holders and beam attenuators.

The auto-correlator for the soft X-ray FEL FLASH at DESY

A new auto-correlator has been developed, built and implemented. It contains eight mirrors on an optical bench, which are independent, adjustable in the nrad and nm range. A parallelogram-based delay stage moves two of the mirrors over ±15 mm with 30 nm resolution and without random parasitic motions. The paper presents the new ideas applied in the design of this device.

Variable line spacing plane grating monochromator for first LNLS undulator beamline

In early 2007 an elliptically polarized Apple II undulator was installed on an LNLS storage ring. It will provide photons to the first PGM beamline at LNLS designed to deliver photons ranging from 100 to 1000 eV with a resolving power of over 10 000. The beamline is about to start the commissioning process and this paper describes mainly the monochromator design and construction.

Prototype testing of a composite-type active grating bender with Si substrate for surface profile high-order term elimination

The previous monolithic active grating bender design met some basic design requirements. However, after a real grating (BM-AGM) had been fabricated and installed for testing, the results showed that the usable length is a mere 60 mm because of the higher-order term error in the surface profile. A method was thus derived to eliminate the higher-order term error by modifying the width of the bender substrate through finite-element method simulation, reducing the residual error from about 100 nm to 6 nm. Owing to the closure of the grating department of Zeiss, ruling the monolithic bender is no longer available and the design has to be modified to a composite-type bender with Si substrate. A prototype was fabricated and assembled to examine all the design situations. The surface roughness of the width-modified Si substrate is around 30 nm before assembly. The residual error after assembly and bending is less than 10 nm. It proves that the design is feasible. However, due to the manufacturing capacity of the vendor, a short-length substrate is required and the design has to be modified. The detailed design modification and testing results are presented in this paper.

Present status of NSLS-II design and construction

National Synchrotron Light Source (NSLS-II) is a new 3 GeV, 500 mA, high-brightness synchrotron light source facility being built at the Brookhaven National Laboratory. Approved for construction in January 2009, the NSLS-II project is expected to be completed in June 2014. In this paper we discuss the present status of the mechanical design and construction of some major components of this facility, namely (i) conventional facilities, (ii) injector complex (iii) storage ring, (iv) RF system and (v) beamlines.

National Synchrotron Light Source II cryogenic plant at BNL

A cryogenic plant will be installed at the National Synchrotron Light Source II (NSLS-II) to supply the liquid helium for six superconducting cavities. This paper describes the configuration of the cryogenic plant and the main design considerations for selecting equipment and components.

Thermo-mechanical analyses of beryllium compound refractive lens for NSLS-II beamline

In this paper we discuss the finite-element analysis (FEA) of a one-dimensional beryllium compound refractive lens (Be-CRL) that was undertaken to study the feasibility of installing the CRL in the Inelastic X-ray Scattering (IXS) beamline of National Synchrotron Light Source-II (NSLS-II) (a new state-of-the-art medium-energy third-generation storage ring). The current insertion device for this beamline is an IVU22-6m in-vacuum planar undulator delivering a total power of ~9 kW with a peak power density of ~90 kW/mrad2. Through analysis, based on calculation of spectral angular distribution of undulator radiation from IVU22, we determined that it is essential to install a 30 µm graphite filter upstream of the CRL in order to restrict the temperature rise in the CRL to 65°C for acceptable thermal strain.

X-ray absorption spectroscopy characterization of the interface in capped ZnO nanoparticles

We report here an extensive study of the ZnO nanoparticles (NPs) capped with different organic molecules by X-ray absorption spectroscopy (XAS) methods to proceed in the understanding of their unusual magnetism. We have performed a detailed ab initio calculation of the Zn K-edge XAS aimed at determining the influence of the different coordination induced by the capping. The results suggest that the observed differences of the XAS spectra are due to the formation of a well-defined interface between the oxide NPs and the capping molecules. The appearance of magnetism should be related to the modifications induced in the NPs by the surface bonds between Zn and the capping molecule.