Browsing by Author "Hagen, ME"
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- ItemDevelopment of a new instrument to observe time-resolved neutron diffraction intensities in association with phase transitions(Australian Institute of Physics, 2005-01-31) Daniels, JE; Studer, AJ; Finlayson, TR; Hagen, METhe study of time-resolved diffraction intensities during a phase transition is important for gaining an understanding of the kinetics involved. Unfortunately the flux needed in order to achieve good counting statistics for a diffraction experiment during a single phase transition is very high. This problem is then compounded if the time scales which need to be observed are very small. Therefore techniques which can take advantage of the reversibility of some phase transitions are potentially beneficial in order to build up statistics. Stroboscopic techniques have been used in recent times to observe diffraction peak intensities with very good time resolution during the application of some type of perturbing field, driving a transition. Most commonly, and as will be the case with this instrument, high electric fields are used to switch single-crystal samples between their paraelectric and ferroelectric phases. Diffraction peaks are observed as a function of time during the switching period [1]. Other types of cycles which have also been used are stress [2], and temperature [3]. In order to carry out these types of experiments, a new capability has been added to The Australian Stress Scanner (TASS) instrument [4] at the High Flux Australian Reactor (HIFAR) operated by the Australian Nuclear Science and Technology Organisation (ANSTO). TASS is the former Triple Axis Spectrometer which, within the last couple of years, has been significantly refurbished (including the introduction of a multi-line, position-sensitive detector) to function as a two-axis diffractometer for strain mapping in engineering materials. This capability will allow for such stroboscopic experiments to be performed using the switching of high-voltage electric fields. The exact operation of the device is outlined in the experimental details section below. The common ferroelectric material, triglycine sulphate, will be used as a model crystal for the commissioning of the stroboscopic technique at HIFAR since, in a previous study involving stroboscopic diffraction intensity measurements at the ISIS [5], most unusual time dependencies for diffraction peak intensities from a TGS crystal in response to the switching of high-voltage electric fields applied to the crystal were observed.
- ItemECHIDNA - getting OPAL’s high resolution powder diffractometer into operation(Australian Institute of Physics, 2006-12-05) Liss, KD; Hunter, BA; Hagen, ME; Noakes, TJA new powder diffractometer aiming for high angular and thus high reciprocal space resolution is being constructed within the Neutron Beam Instrumentation Project at the upcoming Australian Neutron Source OPAL near Sydney. The expected neutron flux at the sample can be expected more than 107 n/s. With an array of 128 position sensitive detectors, each equipped with a 30 cm high Söller collimator of 5 arc min acceptance this instrument will range below the highest performances of its kind. In addition to classical applications in powder diffraction, the quasi two-dimensional detector will be used for rapid texture measurements where high separation of peaks is necessary. Even single crystal reciprocal space mapping will be envisaged [1]. The poster compiles an overview of the installation and commissioning of the new instrument. Neutrons are planned to be available from August 2006 and first experimental data be available for the conference. [1] K.-D. Liss, B. Hunter, M. Hagen, T. Noakes, S. Kennedy: "ECHIDNA - The new high-resolution powder diffractometer being built at OPAL", Physica B, accepted (2006)
- ItemEchidna—the new high-resolution powder diffractometer being built at OPAL(The Bragg Institute, Australian Nuclear Science and Technology Organisation, 2005-11-27) Liss, KD; Hunter, BA; Hagen, ME; Noakes, TJ; Kennedy, SJA new powder diffractometer, named Echidna, aiming for high angular and thus high reciprocal space resolution is being constructed within the Neutron Beam Instrumentation Project at the upcoming Australian Neutron Source OPAL near Sydney. The neutron flux at the sample can be expected to be more than 107 n/s. With an array of 128 position sensitive detectors, each equipped with a 30 cm high Soeller collimator of 5 arc min acceptance this instrument will have one of the highest performances of its kind. In addition to classical applications in powder diffraction, the quasi two-dimensional detector will be used for rapid texture measurements where high separation of peaks is necessary. Even single crystal reciprocal space mapping will be envisaged. The poster compiles an overview of the design, status of the project and potential research to be achieved. © The Authors
- ItemEchidna—the new high-resolution powder diffractometer being built at OPAL(Elsevier B. V., 2006-11-15) Liss, KD; Hunter, BA; Hagen, ME; Noakes, TJ; Kennedy, SJA new powder diffractometer aiming for high angular, and thus high reciprocal space, resolution is being constructed within the Neutron Beam Instrumentation Project at the upcoming Australian Neutron Source OPAL, near Sydney. The neutron flux at the sample can be expected to be up to 107 n/cm2/s. With an array of 128 position sensitive detectors, each equipped with a 30 cm high Söller collimator of 5 arc min acceptance this instrument will have one of the highest performances of its kind. In addition to classical applications in powder diffraction, the quasi two-dimensional detector will be used for rapid texture measurements, where high separation of peaks is necessary. Even single crystal reciprocal space mapping is envisaged. The article compiles an overview of the design, status of the project and potential research activities. Crown Copyright © 2006 Published by Elsevier B.V
- ItemHigh intensity and high resolution neutron powder diffraction at the replacement research reactor(Australian Institute of Physics, 2004-02-04) Hagen, ME; Hunter, BA; Noakes, TJNeutron powder diffraction is an established technique for studying the structures of crystalline materials. In any diffraction experiment the two most basic quantities which characterise the quality of the measured spectra are resolution and intensity. High-resolution measurements are used to determine precise and intricate details of the crystal structure, while high intensity measurements are used to characterise changes driven in real time by in-situ measurements. In both cases recent developments in the instrumentation have focussed on the use of position sensitive and area detectors to increase the effective count rate in high resolution and high intensity measurements respectively. We will describe the characteristics of the High Intensity Powder Diffractometer (Wombat) and the High Resolution Powder Diffractometer (Echidna), which are currently under construction at the replacement research reactor, ANSTO and which will be available to the Australian scientific community in 2006.
- ItemThe instrument suite of the European Spallation Source(Elsevier B. V., 2020-01-10) Andersen, KH; Argyriou, DN; Jackson, AJ; Houston, J; Henry, PF; Deen, PP; Toft-Petersen, R; Beran, P; Strobl, M; Arnold, T; Wacklin-Knecht, H; Vivanco, R; Parker, SF; Gussen, A; Kanaki, K; Scionti, G; Olsen, MA; Arai, M; Schmakat, Ph; Lechner, RE; Niedermayer, Ch; Schneider, H; Zanetti, M; Petrillo, C; Moreira, FY; Stepanyan, S; Luna, P; Calzada, E; Stahn, J; Voigt, J; Dupont, T; Hanslik, R; Siemers, DJ; Udby, L; Chowdhury, MAH; Klauser, Ch; Rouijaa, M; Lehmann, E; Heynen, A; Bustinduy, I; Schwaab, A; Raspino, D; Scatigno, C; del Moral, OG; Kiehn, R; Aprigliano, G; Zanatta, M; Huerta, M; Bellissima, S; Lerche, M; Holm-Dahlin, S; Huerta, M; Christensen, NB; Lohstroh, W; Gorini, G; Fenske, J; Hansen, UB; Klauser, C; Rodrigues, S; Müller, M; Gorini, G; Bovo, C; Hall-Wilton, R; Fabrèges, X; Siemers, DJ; Khaplanov, A; Tsapatsaris, N; Taylor, J; Christensen, M; Schefer, J; Woracek, R; Tozzi, P; Müller, M; Carlsen, H; Olsen, MA; Orecchini, A; Di Fresco, L; Paciaroni, A; Bovo, C; Magán, M; Hauback, BC; Elmer, J; Heenan, RK; Piscitelli, F; Masi, F; Bakedano, G; Klimko, S; De Bonis, A; Fedrigo, A; Lukáš, P; Frielinghaus, H; Stahn, J; Schweika, W; Markó, M; Pfeiffer, D; Kirstein, O; Di Fresco, L; Schreyer, A; Orszulik, A; Nowak, G; Butterweck, S; Šaroun, J; Paciaroni, A; Kolevatov, R; Lehmann, EH; Filges, U; Schreyer, A; Koenen, M; Bustinduy, I; Magán, M; Feygenson, M; Cooper, JFK; Abad, E; Senesi, R; Longeville, S; Llamas-Jansa, I; Schulz, M; Birk, JO; Sharp, M; Galsworthy, P; Šaroun, J; Martínez, J; Hiess, A; Holm-Dahlin, S; Filges, U; Pullen, SA; Guyon Le Bouffy, J; Schefer, J; Lukáš, P; Udby, L; Kozielewski, T; Niedermayer, C; Sacchetti, F; Hartl, M; Jaksch, S; Salhi, Z; Brückel, T; Aguilar, J; Aguilar, J; Seifert, M; Bordallo, HN; Robillard, T; Villacorta, FJ; Herranz, I; del Rosso, L; Hauback, BC; Orecchini, A; Fabrèges, G; Fenske, J; Neuhaus, J; Schillinger, B; Abad, E; Kittelmann, T; Lefmann, K; Seifert, M; Neuhaus, J; Herranz, I; Kolevatov, R; Annighöfer, B; Oksanen, E; Morgano, M; Laszlo, G; Freeman, PG; Kennedy, SJ; Bertelsen, M; Bellissima, S; Alba-Simionesco, C; Markó, M; Mezei, F; Chowdhury, M; Halcrow, W; Jestin, J; Lieutenant, K; Babcock, E; Rønnow, HM; Engels, R; del Moral, OG; Vickery, A; Rouijaa, M; Lavie, P; Petersson Årsköld, S; Glavic, A; Désert, S; Mannix, D; Scatigno, C; Petry, W; Christensen, NB; Violini, N; Villacorta, FJ; Porcher, F; Glavic, A; Scionti, G; Zanetti, M; Fernandez-Alonso, F; Rønnow, HM; Mosconi, M; Olsson, M; Stepanyan, S; Petrillo, C; del Rosso, L; Harbott, P; Sacchetti, F; Bertelsen, M; Kämmerling, H; Andreani, C; Schulz, M; Colognesi, D; Luna, P; Loaiza, L; Turner, D; Martínez, JL; Tartaglione, A; Sordo, F; Llamas-Jansa, I; Schmakat, P; Lechner, RE; Poqué, A; Fernandez-Alonso, F; Colognesi, D; Tartaglione, A; Morgano, M; Webb, N; Loaiza, L; Whitelegg, L; Petry, W; Iversen, K; Vivanco, R; Tozzi, P; Goukassov, A; Schillinger, B; Carlsen, H; Masi, F; Christensen, M; Nowak, G; Nightingale, J; Schütz, S; Lopez, CI; Langridge, S; Schütz, S; Nagy, G; Zanatta, M; Andreani, C; Lefmann, K; Lohstroh, W; Mosconi, M; Senesi, R; Stefanescu, I; Bakedano, G; Hagen, ME; Wischnewski, A; Bourges, P; Hansen, UB; De Bonis, A; Kiehn, R; Parker, SF; Iversen, K; Sordo, F; Freeman, PG; Birk, JO; Rodríguez, DM; Ansell, SAn overview is provided of the 15 neutron beam instruments making up the initial instrument suite of the European Spallation Source (ESS), and being made available to the neutron user community. The ESS neutron source consists of a high-power accelerator and target station, providing a unique long-pulse time structure of slow neutrons. The design considerations behind the time structure, moderator geometry and instrument layout are presented. The 15-instrument suite consists of two small-angle instruments, two reflectometers, an imaging beamline, two single-crystal diffractometers; one for macromolecular crystallography and one for magnetism, two powder diffractometers, and an engineering diffractometer, as well as an array of five inelastic instruments comprising two chopper spectrometers, an inverse-geometry single-crystal excitations spectrometer, an instrument for vibrational spectroscopy and a high-resolution backscattering spectrometer. The conceptual design, performance and scientific drivers of each of these instruments are described. All of the instruments are designed to provide breakthrough new scientific capability, not currently available at existing facilities, building on the inherent strengths of the ESS long-pulse neutron source of high flux, flexible resolution and large bandwidth. Each of them is predicted to provide world-leading performance at an accelerator power of 2 MW. This technical capability translates into a very broad range of scientific capabilities. The composition of the instrument suite has been chosen to maximise the breadth and depth of the scientific impact of the early years of the ESS, and provide a solid base for completion and further expansion of the facility. © 2020 The Authors. Published by Elsevier B.V. Open access article under the CC BY-NC-ND license.
- ItemNeutron diffraction studies of the ferroelectric/paraelectric transition in triglycine sulphate(Australian Institute of Physics, 2005-01-31) Daniels, JE; Piltz, RO; Hagen, ME; Finlayson, TRThis research is a preliminary study in preparation for relaxation measurements using the stroboscopic neutron diffraction technique being presented at this congress. Triglycine sulphate, TGS, is a ferroelectric material with important potential for its pyroelectric applications. However, despite a number of structural studies of TGS in the literature, many have been done using x-ray diffraction and so uncertainty remains in regards to the precise hydrogen atom positions and the role of hydrogen bonding in the transition to the ferroelectric state. In this paper, structural studies using single-crystal neutron diffraction at temperatures in the vicinity of the Curie temperature, will be presented. © (2005) Australian Institute of Physics.
- ItemSpin exchange optical pumping based polarized He-3 filling station for the hybrid spectrometer at the spallation neutron source(American Institute of Physics, 2013-06-01) Jiang, CY; Tong, X; Brown, DR; Culbertson, H; Graves-Brook, MK; Hagen, ME; Kadron, B; Lee, WT; Robertson, JL; Winn, BThe Hybrid Spectrometer (HYSPEC) is a new direct geometry spectrometer at the Spallation Neutron Source at the Oak Ridge National Laboratory. This instrument is equipped with polarization analysis capability with 60 degrees horizontal and 15 degrees vertical detector coverages. In order to provide wide angle polarization analysis for this instrument, we have designed and built a novel polarized He-3 filling station based on the spin exchange optical pumping method. It is designed to supply polarized He-3 gas to HYSPEC as a neutron polarization analyzer. In addition, the station can optimize the He-3 pressure with respect to the scattered neutron energies. The depolarized He-3 gas in the analyzer can be transferred back to the station to be repolarized. We have constructed the prototype filling station. Preliminary tests have been carried out demonstrating the feasibility of the filling station. Here, we report on the design, construction, and the preliminary results of the prototype filling station. © 2013, American Institute of Physics.
- ItemThe TAIPAN thermal triple-axis spectrometer at the OPAL reactor(Australian Institute of Physics, 2006-12-05) Danilkin, SA; Horton, G; Moore, R; Hagen, MEInelastic neutron scattering is a widely used technique to study phonon and magnon excitations in condensed matter and the triple axis spectrometer (TAS) is one of the main instruments used for such inelastic neutron scattering studies. As consequence the TAIPAN TAS will be the first inelastic instrument at the new Australian research reactor OPAL. It will be located on a thermal neutron beam tube at the reactor shielding face and can be operated either in a high flux mode with a double focusing monochromator and analyser, or in a traditional mode of operation with Soller collimators providing high resolution. A polarisation analysis capability will be realised on TAIPAN using supermirror benders. The spectrometer is currently under fabrication and should be commissioned at the beginning of 2007. We present the design and expected performance of the instrument.
- ItemTAIPAN – a spectrometer for inelastic neutron scattering at the replacement research reactor(Australian Institute of Physics, 2004-02-04) Hagen, ME; Horton, G; Moore, R; Braoudakis, G; Cussen, LDInelastic neutron scattering is widely used to study the lattice vibrational (phonon) and magnetic (spin wave and crystal field) excitations in condensed matter. In order to characterise such excitations comprehensively measurements on single crystal specimens are required and the most appropriate instrument for doing this at a steady state (reactor) neutron source is a three-axis spectrometer (TAS). We will describe the characteristics of the three axis spectrometer TAIPAN, which is currently under construction at the replacement research reactor, ANSTO and which will be available to the Australian scientific community in 2006.
- ItemThermal triple-axis spectometer at OPAL Reactor(Australian Institute of Physics, 2006-02-07) Danilkin, SA; Horton, G; Moore, R; Braoudakis, G; Hagen, MEInelastic neutron scattering is widely used to study the excitations such as phonon and magnon in condensed matter. A triple–axis spectrometer (TAS) is one of main instruments used in neutron scattering studies. TAS TAIPAN will be the first inelastic instrument at the Australian research reactor OPAL. It will be placed at a reactor face position and will use double focusing monochromators and analyser. In addition to the double-focusing regime, TAIPAN will have a standard mode of operation with Soller collimators providing high resolution. The instrument will use supermirror benders for polarization analysis.
- ItemTime resolved neutron diffraction studies of triglycine sulphate near the ferroelectric transition during the application of high voltage electric fields(The Bragg Institute, Australian Nuclear Science and Technology Organisation, 2005-11-27) Daniels, JE; Finlayson, TR; Studer, AJ; Hagen, MEA new capability has been added to The Australian Stress Scanner (TASS), to allow the real-time response of neutron Bragg reflections to be monitored during the application of High Voltage fields. These experiments are performed using a stroboscopic technique which allows for timing resolutions below 30mus. Initial experiments using the new instrument have focussed on applying fields of up to 5kV/cm to samples of the ferroelectric triglycine sulphate (TGS), held at temperatures close to its ferroelectric/paraelectric transition temperature. The real-time responses of (0k0) type Bragg reflections in TGS show some unusual properties. In particular the (060) reflection shows several responses to the application of the field, including long relaxations over several seconds, as well as short spikes in intensity at field on and field off conditions which decay over approximately 150mus. This paper will present some of the recent data along with a discussion of the physical mechanisms leading to the intensity changes in Bragg reflections. © 2005 The Authors
- ItemTime-resolved neutron diffraction studies of triglycine sulphate near the ferroelectric transition during the application of high-voltage electric fields(Elsevier B. V., 2006-11-15) Daniels, JE; Finlayson, TR; Studer, AJ; Hagen, MEAn experimental facility to measure the time dependence of neutron Bragg peak intensities, in response to applied high-voltage electric fields is described. The stroboscopic technique with a timing resolution below 20 μs has been applied to study crystals of tryglycine sulphate near its ferroelectric transition temperature and in this paper data are presented showing the response of the (0 6 0) reflection to an applied field square wave at 1 kHz for various temperatures. © 2006 Elsevier B.V.
- ItemTime-resolved neutron diffraction studies: the ferroelectric transition in triglycine sulphate(Australian Institute of Physics, 2006-02-07) Daniels, JE; Finlayson, TR; Studer, AJ; Hagen, MEA stroboscopic technique has been developed enabling the real-time response of neutron Bragg reflections to be monitored during the application of highvoltage fields to a crystal. The real-time responses of reflections from triglycine sulphate at temperatures in the vicinity of its ferroelectric/ paraelectric transition show some unusual properties. Some of the recent data from these experiments are presented together with a discussion of the physical mechanisms leading to changes in Bragg reflection intensities.
- ItemWOMBAT: the high intensity powder diffractometer at the OPAL Reactor(The Bragg Institute, Australian Nuclear Science and Technology Organisation, 2005-11-27) Studer, AJ; Hagen, ME; Noakes, TJThe WOMBAT powder diffractometer will be located on the TG1 thermal guide at the OPAL reactor. A variable vertically focusing monochromator will provide a flux of up to ∼ 108 n.s-1.cm-2 at the sample position. A compact curved 2D position sensitive detector will allow simultaneous acquisition of 120 degrees in 2θ, with ∼ 106s-1 count rate capability and time resolution down to the microsecond level. WOMBAT is designed for experiments requiring rapid real time acquisition (time resolved environmental or kinetics experiments) or very good signal to noise (experiments with difficult sample environments or small sample volumes). © The Authors
- ItemWombat: the high-intensity powder diffractometer at the OPAL reactor(Elsevier B. V., 2006-11-15) Studer, AJ; Hagen, ME; Noakes, TJThe Wombat powder diffractometer will be located on the TG1 thermal guide at the OPAL reactor. A variable vertically focusing monochromator will provide a flux of up to ≈108 ns−1 cm−2 at the sample position. A compact curved 2D position sensitive detector will allow simultaneous acquisition of 120 ° in 2θ, with ≈106 s−1 count rate capability and time resolution down to the microsecond level. Wombat is designed for experiments requiring rapid real time acquisition (time-resolved environmental or kinetics experiments) or very good signal to noise (experiments with difficult sample environments or small sample volumes). Crown Copyright © 2006 Published by Elsevier B.V.