R. Neuenschwander - Academia.edu (original) (raw)

Papers by R. Neuenschwander

A magnetic measurements facility has been set up for characterization and experimental developmen... more A magnetic measurements facility has been set up for characterization and experimental development of the LNLS (Laboratorio Nacional de Luz Sincrotron) magnets. Measurements are computer-controlled and include field mapping and harmonic analysis. The main characteristics of the measuring instruments developed at LNLS are presented, as well as results obtained during test runs

In early 2007 an elliptically polarized Apple II undulator was installed on an LNLS storage ring.... more 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.

ABSTRACT A chamber for in situ WAXS, SAXS and GISAXS studies of polycrystalline and amorphous mat... more ABSTRACT A chamber for in situ WAXS, SAXS and GISAXS studies of polycrystalline and amorphous materials was designed and constructed. It is used under vacuum or filled with a gas mixture to operate as a reactor where a plasma for materials surface treatment is produced. The WAXS intensity is recorded by an external imaging plate moving parallel to the chamber axis, making it possible to obtain successive patterns during in situ studies of structural transformations. The chamber is also used for classical SAXS and GISAXS studies of thin films.

PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268), 2001

We present results of the commissioning of a new injector for the Brazilian Synchrotron Light Sou... more We present results of the commissioning of a new injector for the Brazilian Synchrotron Light Source. The new injector consists of the existing 125-MeV LINAC and a new 500-MeV booster synchrotron. At present, about 40 mA can be injected into the booster and about 15 mA can be ramped up to 500 MeV at a repetition rate of 0.17 Hz. The new injector has allowed the accumulation of up to 540 mA in the main ring at 500 MeV and up to 305 mA has been ramped up to the storage ring nominal energy of 1.37 GeV. The new beam intensity is more than twice as large as the typical stored beam current before the installation of the booster synchrotron.

$Research paper thumbnail of Advanced Facility for Parallel Thermo-Mechanical Simulation and Synchrotron X-Ray Diffraction$

In-situ Studies with Photons, Neutrons and Electrons Scattering II, 2014

Proceedings of the 1997 Particle Accelerator Conference (Cat. No.97CH36167), 1998

The Brazilian National Synchrotron Light Laboratory, LNLS, operates a 1.37 GeV electron storage r... more The Brazilian National Synchrotron Light Laboratory, LNLS, operates a 1.37 GeV electron storage ring with a 120 MeV injector Linac. Commissioning of the storage ring at low energy started on May 1996 and now, an year later, we can store 120 mA at 120 MeV and ramp more than 75 mA to 1.37 GeV. A summary of the latest commissioning results and a description of the present operational performance of the LNLS Synchrotron Light Source facility is presented. 811 0-7803-4376-X/98/$10.00

Proceedings of the 1989 IEEE Particle Accelerator Conference, . 'Accelerator Science and Technology, 1989

We present a general review of the LNLS Synchrotron Light Source magnets, outlining the most impo... more We present a general review of the LNLS Synchrotron Light Source magnets, outlining the most important parameters related to their design, construction and characterization.

Journal of Physics: Conference Series, 2013

We present the U11 beam line at the National Synchrotron Light Laboratory (LNLS), Brazil. This is... more We present the U11 beam line at the National Synchrotron Light Laboratory (LNLS), Brazil. This is the first undulator based beam line installed at the UVX storage ring. It is based on the collimated plane grating monochromator design, which allows for variation in included angle of the grating. The results obtained during the commissioning demonstrate a good overall performance in terms of energy resolution and beam size, in accord with the expected values obtained from ray tracing calculation.

Caixa Postal 6192 --13081-970 Campinas -SP -Brazil.

cdsweb.cern.ch

Craievich, AF; Farias, RHA; Ferreira, MJ; Fraguas, G; Franco, J; Gonçalves da Silva, CET; Jahnel,... more Craievich, AF; Farias, RHA; Ferreira, MJ; Fraguas, G; Franco, J; Gonçalves da Silva, CET; Jahnel, LC; Lin, L; Lira, AC; Neuenschwander, RT; Pardine, C; Rafael, F; Rodrigues, ARD; Rosa, A; Scorzato, C; Tavares, PF; Wisnivesky, D; Da Silva, AR. Skip to main content. ...

Proceedings of the 2005 Particle Accelerator Conference, 2005

We present the results of the commissioning of a 28-pole 2 T Hybrid Wiggler at the electron stora... more We present the results of the commissioning of a 28-pole 2 T Hybrid Wiggler at the electron storage ring of the Brazilian Synchrotron Light National Laboratory (LNLS). The wiggler will be used mainly for protein crystallography and was optimized for the production of 12 keV photons. We describe the effects of the insertion device on the storage ring lattice, such

$Research paper thumbnail of Reactive sputter magnetron reactor for preparation of thin films and simultaneous in situ structural study by X-ray diffraction$

Review of Scientific Instruments, 2013

The purpose of the designed reactor is (i) to obtain polycrystalline and∕or amorphous thin films ... more The purpose of the designed reactor is (i) to obtain polycrystalline and∕or amorphous thin films by controlled deposition induced by a reactive sputtering magnetron and (ii) to perform a parallel in situ structural study of the deposited thin films by X-ray diffraction, in real time, during the whole growth process. The designed reactor allows for the control and precise variation of the relevant processing parameters, namely, magnetron target-to-sample distance, dc magnetron voltage, and nature of the gas mixture, gas pressure and temperature of the substrate. On the other hand, the chamber can be used in different X-ray diffraction scanning modes, namely, θ-2θ scanning, fixed α-2θ scanning, and also low angle techniques such as grazing incidence small angle X-ray scattering and X-ray reflectivity. The chamber was mounted on a standard four-circle diffractometer located in a synchrotron beam line and first used for a preliminary X-ray diffraction analysis of AlN thin films during their growth on the surface of a (100) silicon wafer.

Review of Scientific Instruments, 2004

Two different vacuum tight sample cells for in situ temperature dependent small angle scattering ... more Two different vacuum tight sample cells for in situ temperature dependent small angle scattering from liquids are presented in this article. In the first one, the sample fills a 1 mm thickness gap sealed on both sides by two thin parallel mica windows (volume 300 l). In the second one, the liquid is injected into a 1 mm cylindrical capillary tube (volume 130 l). The cells are lodged into temperature controlled chambers directly connected to the beamline vacuum path. Several important improvements with respect to similar instrumentation previously reported are: (1) versatile application of the mica cell, that can be used for all types of samples (gels, liquid crystals, and dispersions in organic solvents) and (2) the design of the chamber for the capillary cell allows registration of wider angle data and a convenient replacement of the capillary tube after each experiment. Signal to background ratio and data reproducibility were tested using protein solutions. We give a brief report of scattering experiments performed with different protein samples and two-dimensional data collection.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2003

The setup was designed for in situ studies of structural transformations in materials at high tem... more The setup was designed for in situ studies of structural transformations in materials at high temperatures. It makes possible simultaneous recording of wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) spectra from room temperature up to 1000 °C. The setup was installed in the National Synchrotron Light Laboratory SAXS beamline. It was applied to in situ studies of several

$Research paper thumbnail of High-resolution X-ray diffraction beamline at the LNLS for the study of charge, orbital and magnetic structures$

Journal of Synchrotron Radiation, 2003

A high-resolution X-ray diffraction beamline at the Brazilian Synchrotron Light Laboratory (LNLS)... more A high-resolution X-ray diffraction beamline at the Brazilian Synchrotron Light Laboratory (LNLS) has been commissioned for the study of crystalline magnetic materials. The beamline optics is based on a Rh-coated vertical-focusing X-ray mirror and a sagittalfocusing double-crystal monochromator. The primary instrument is a six-circle diffractometer equipped with energy and polarization analysers and a closed-cycle He cryostat. The beamline source is a bending magnet of the 1.37 GeV storage ring of the LNLS, delivering approximately 4 Â 10 10 photons s À1 at 8 keV at the sample position. Resonant and non-resonant scattering are the main techniques used to study charge, orbital and magnetic structures. Examples of magnetic scattering in Ho and NiO single crystals, as well as orbital ordering in manganites thin ®lms, are presented.