Browsing by Author "Pullen, SA"

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    100-position robotic sample changer for powder diffraction with low-background vacuum chamber
    (Wiley-Blackwell, 2010-04) Olsen, SR; Pullen, SA; Avdeev, M
    At the new Australian OPAL research reactor, experiments carried out at room temperature use a substantial fraction of beam time on the high-resolution powder diffractometer, Echidna. With an average data collection time of 2 h and a complicated safety interlock system to protect users, the need for a fully automated and remotely controlled system was quickly realized. This report presents a solution based on a commercial four-axis robot capable of loading samples from two 50-position sample trays, in any order, into an automatically evacuated chamber. This chamber significantly reduced background signal arising from air scattering, with the effect being especially pronounced at low and high 2 angles. In the case of textured or inhomogeneous samples, the system may be re-configured so that the robot rotates the sample in the beam or translates it vertically through the beam. © 2010, Wiley-Blackwell.
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    Design and implementation of a differential scanning calorimeter for the simultaneous measurement of small angle neutron scattering
    (IOP Science, 2014-04-08) Pullen, SA; Booth, N; Olsen, SR; Day, B; Franceschini, F; Mannicke, F; Gilbert, EP
    For almost 30 years, at synchrotron facilities, it has been possible to perform small-angle x-ray scattering experiments whilst simultaneously measuring differential scanning calorimetry (DSC). However, a range of challenges exist to enable the collection of simultaneous small-angle neutron scattering (SANS) and DSC data associated not only with intrinsic flux limitations but also scattering geometry and thermal control. The development of a DSC (temperature range ca. −150 ◦C to 500 ◦C) suitable for SANS is detailed here and its successful use is illustrated with combined measurements on a binary blend of normal alkanes in which one component has been deuterium labelled. © 2014, IOP Publishing Ltd
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    First application of simultaneous sans and differential scanning calorimetry: microphase separated alkane blends
    (International Conference on Neutron Scattering, 2017-07-12) Pullen, SA; Booth, N; Olsen, SR; Franceschini, F; Mannicke, D; Gilbert, EP
    The combination of small-angle x-ray scattering experiments with simultaneous measurement of phase transitions using differential scanning calorimetry (DSC) has become common-place. However, no such facility existed, until recently to enable the simultaneous measurement of DSC and small angle neutron scattering (SANS). DSC data complements SANS by providing first and second order phase transition temperatures and, with appropriate calibration, the magnitude and sign of associated enthalpy changes due to these phase transitions. A range of challenges have been addressed to enable the collection of simultaneous SANS and DSC data associated not only with intrinsic flux limitations but also scattering geometry, thermal control and synchronisation of the DSC and SANS data. The development of a DSC suitable for SANS is detailed here which, to our knowledge, is the first and only one of its kind. The resulting instrument has a temperature range of -50?C to 500?C and a furnace geometry that allows access to the full q range of QUOKKA, at the OPAL reactor to be reached. The DSC-SANS was first used to investigate the behaviour of binary mixtures of normal alkanes which is presented here although several further successful experiments have been carried out since on range of soft and hard condensed matter samples.
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    Hot commissioning and first user experiments on the Spatz neutron reflectometer
    (Australian Nuclear Science and Technology Organisation, 2021-11-26) Le Brun, AP; Huang, TY; Pullen, SA; Nelson, A; Holt, SA
    The Spatz neutron beam instrument is the latest to be installed and commissioned in the Neutron Guide Hall at the 20 MW OPAL Research Reactor. Spatz is a time-of-flight neutron reflectometer used for studying nanoscale structures at surfaces and interfaces and utilises a vertical sample geometry / horizontal scattering geometry. The instrument is situated at the end position of the CG2B neutron guide and views the cold neutron source (CNS). The disc chopper cascade that pulses the neutron beam to produce the time-of-flight is very configurable to provide a wavelength resolution between 1 to 12 %. The detector is a helium-3 two dimensional detector that is capable of measuring both specular and off-specular reflectivity. The sample stage can support a range of different sample environments including multiple solid-liquid cells, an atmospheric chamber with temperature control, the ATR-FT-IR spectrometer for simultaneous infra-red spectroscopy and neutron reflectometry measurements, electrochemical cells, etc. The geometry of the instrument and the sample environment available means that Spatz is well suited to studying phenomena at the gas-solid interface and solid-liquid interface. The Spatz instrument has been fully commissioned with neutrons and the results of the commissioning are presented. This includes measurements using the ‘Bragg mirror’ consisting of 25 bilayers of nickel and titanium, different solid substrates of silicon, quartz and sapphire, spin-coated polymer samples, and films under liquid. Reflectivity down to 10-7 can be achieved within 1 hour measuring time with good counting statistics in most cases. Early user experiments cover a range of science including investigating the thermal stability of organic solar cell materials and proteins interacting with biomimetic phospholipid cell membranes. © 2021 The Authors
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    An in situ rapid heat-quench cell for small-angle neutron scattering
    (Institute of Physics, 2008-06) Pullen, SA; Gilbert, EP; Olsen, SR; Lang, EA; Doolan, KR
    A dual-temperature sample environment has been developed enabling the rapid heating and quenching of samples in situ for small-angle neutron scattering (SANS). The rapid heat and quench cell (RHQC) allows samples to be rapidly heated up to 600 K and then quenched to 150 K, or vice versa, in a single shot or cycle mode, with the sample in position for data collection. Measured cooling rates of up to 11 K s-1 and heating rates up to 19 K s-1 have been recorded during the testing stages. First results using the RHQC on a hydrogenated/deuterated paraffin blend quenched from the melt illustrate the value of the device in accessing the early stage phase separation kinetics with SANS. © 2008, Institute of Physics
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    The 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, J; 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, S
    An 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.
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    Novel non destructive sample analysis techniques using neutron scattering
    (Engineers Australia, 2014-01-01) Olsen, SR; Gilbert, EP; Booth, N; Pullen, SA; Imperia, P; Peterson, VK; Garbe, U; Luzin, V; Paradowska, AM; Studer, AJ; Liss, KD
    In late 2006 the new 20MW Open Pool Australian Light Water Reactor (OPAL) went critical for the first time. Since 2007 thousands of scientists and engineers have used the neutron beam instruments to perform a wide range of non-destructive studies of samples covering physics, chemistry, biology, engineering and materials science. Neutrons provide a wealth of information about the state of materials including structure, residual stress, magnetic properties and dynamic properties. As neutrons scatter from nuclei and not electrons, they are highly penetrating, capable of travelling tens of millimeters into most metals. Neutrons behave, for to some extent, like tiny bar magnets and therefore can be used to investigate the magnetic properties of materials such as superconductors and computor memories. Recent engineering studies - often undertaken in situ at industrially relevant conditions - include railway sleepers, turbine blades, polymer processing, lithium battery testing, and titanium alloys. © 2021 Informit
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    Report on the repair of the OPAL neutron beam transport system
    (International Group On Research Reactors, 2013-10-13) Pullen, SA; Davidson, G; Pangelis, S; Klose, F; Kennedy, SJ
    The OPAL research reactor commenced operation early in 2007, and has been in continuous operation for most of the time since then. Initial characterization measurements of the cold and thermal neutron beams that feed the neutron guide hall confirmed the high fluxes that had been predicted in the design process [1], [2]. However, by 2011 it was clear that the performance of the neutron guide system had degraded substantially. Investigation revealed that the degradation resulted from delamination of the guides. The root cause was build-up of mechanical stress in the glass substrates due to alpha radiation produced during neutron capture by boron in the glass. Remediation involved replacement of 72 metres of the neutron guide system with guides that use glass substrates which have higher radiation resistance. Neutron flux and spectrum measurements have since verified that the performance of the system has largely been restored. Preliminary measurements at the neutron spectrometers since repair reveal flux increases in the range of 40 % to 90 % relative to 2011. © The Authors
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    Safety interlock and vent system to alleviate potentially dangerous ice blockage of top-loading cryostat sample sticks
    (Wiley-Blackwell, 2013-08-01) Pangelis, S; Olsen, SR; Scherschligt, J; Leao, JB; Pullen, SA; Dender, D; Hester, JR; Imperia, P
    A combined solution is presented for minimizing the safety hazards associated with closed cycle cryostats described by Swainson & Cranswick [J. Appl. Cryst. (2010), 43, 206-210]. The initial solution is to install a vent tube with one open end deep inside the sample space and a pressure relief valve at the top. This solution works for either a cryogen or a cryogen-free (closed cycle) system. The second approach, which can be combined with the first and is applicable to cryogen-free cryostats, involves electrically interlocking the closed cycle refrigerator compressor to the sample space, so that the system cannot be cooled in the presence of a leak path to air. © 2013, Wiley-Blackwell.
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    SPATZ: The second time-of-flight neutron reflectometer at the OPAL Research Reactor
    (International Conference on Neutron Scattering, 2017-07-12) Le Brun, AP; Pullen, SA; Constantine, P; Spedding, J; Roach, D; McGregor, A; Affleck, J; Christoforidis, J
    In September 2015, an agreement was signed between HZB and ANSTO to transfer the V18 ‘BioRef’ time-of-flight neutron reflectometer [1, 2], which was situated at the BER-II Research Reactor, to the OPAL Research Reactor. In September 2016 a joint team of ANSTO and HZB personnel spent four weeks carefully disassembling BioRef and packing it into shipping containers for transport to ANSTO. The instrument safely arrived in Sydney in February 2017 [3], and will be known as SPATZ (German for Sparrow). SPATZ will be the 15th neutron-scattering instrument at OPAL. SPATZ has a vertical sample geometry, which complements the current reflectometer, PLATYPUS, which has a horizontal sample geometry. The vertical sample geometry will allow for use of sample environments which cannot be currently used on PLATYPUS due to geometry constraints and allows for wide-angle diffraction from multilayers and lamellarstacks. SPATZ will continue to be equipped for simultaneous infra-red spectroscopy and reflectometry experiments, and will come with equipment for upgrades for polarisation and spin-echo techniques. The instrument will view the OPAL cold neutron source (CNS) by taking the end position of the CG2B guide. Currently, the CG2B guide is installed between the primary and secondary shutters and part of the project scope is to complete the installation of the CG2B guide beyond the secondary shutter into the Neutron Guide Hall. The CG2B guide will accommodate SPATZ and an additional upstream instrument to be determined in the future. This presentation will provide an overview of the project, its current status, and future direction.
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    SPATZ: The second time-of-flight neutron reflectometer at the OPAL Research Reactor
    (Australian Institute of Nuclear Science and Engineering, 2016-11-29) Le Brun, AP; Pullen, SA; Constantine, P; Spedding, J; Roach, D; McGregor, A; Affleck, J; Christoforidis, J; Trapp, M; Steitz, R
    In September 2015, an agreement was signed between HZB and ANSTO to transfer the V18 ‘BioRef’ time-of-flight neutron reflectometer [1], currently situated at the 10 MW BER-II Research Reactor, to the OPAL Research Reactor. During 2016 preparations have been made to carry out the transfer of a neutron-scattering instrument halfway around the globe. This has involved a joint team of ANSTO and HZB personnel spending four weeks carefully disassembling BioRef and packing it into shipping containers for transport to ANSTO. Once the instrument arrives it will be known as SPATZ (German for Sparrow) and will be the 15th neutron-scattering instrument at OPAL. SPATZ has a vertical sample geometry, which complements the current reflectometer, PLATYPUS, which has a horizontal sample geometry. The vertical sample geometry will allow for use of sample environments which cannot be currently used on PLATYPUS due to geometry constraints and allows for wide-angle diffraction from multilayers and lamellar stacks. SPATZ will also be equipped for simultaneous infra-red spectroscopy and reflectometry experiments, and will come with equipment for upgrades for polarisation and spin-echo techniques. The instrument will view the OPAL cold neutron source (CNS) by taking the end position of the CG2B guide. Currently, the CG2B guide is installed between the primary and secondary shutters and part of the project scope is to complete the installation of the CG2B guide beyond the secondary shutter into the Neutron Guide Hall. The CG2B guide will accommodate SPATZ and an additional upstream instrument to be determined in the future. This presentation will provide an overview of the project, its current status, and future direction. Feedback from the neutron scattering community is encouraged.