Browsing by Author "Manning, AG"
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- ItemAdvanced sample environment support for neutron instruments at the Bragg Institute, ANSTO(Australian Institute of Physics, 2016-02-04) Imperia, P; Booth, N; Lee, S; D'Adam, TM; Manning, AGOver the last few years a number of advancements have been made in sample environments available to scientists visiting the Neutron Beam Facility run by the Bragg institute at ANSTO (Lucas Heights). Conventional sample environment equipment allows experiments to be carried out from 35mK to 1700K, magnetic fields up to 12T and electric fields up to 10kV. These extremes are not available on all neutron instruments nor with one piece of equipment. However combinations of temperature, magnetic and electric fields are also possible. These conventional sample environments will not be covered here. This presentation will outline advances made in the gas handling, vapour delivery, differential scanning calorimetry (DSC) and spectroscopy at extreme temperatures all carried out simultaneously with neutron data collection. Some examples of the complimentary data collected are also presented. Our automated gas handling system allows gas mixing (up to 4 gases), dosing (volumetric Sievert analysis) up to 200Bar, gas flow and molecular analysis with a dedicated mass spectrometer for kinetics investigations. The Hiden Isochema system is based on their commercial IMI system with the standard reaction chamber removed and replaced by thermalised capillary lines to allow the gas delivery to a sample reactor placed within a cryostat or furnace on the sample stage of our neutron instruments. Two options are available for vapour delivery. For samples that do not outgas a static system can be used where computer controlled valves control the vapour pressure. One valve is used to lower the pressure using a turbo pump and the second one to allow the vapour from the reservoir to increase the vapour pressure. Any non-corrosive liquid can be used in this system. The second vapour system, dynamically controls the vapour and dry gas flow allowing mixing of two vapours and a dry stream of gas or the recirculation of a saturated vapour through a sample reactor The DSC system is based on A Mettler Toledo model DSC1. The furnace has been moved to allow the passage of the neutron beam and Bragg designed crucibles are used to allow scattering experiments to be carried out while DSC data are collected. Quartz and Aluminium crucibles are available and temperature range of 550C to -100C is achievable. Using Ocean Optics spectrometer equipment we have successfully carried out NIR spectroscopy down to 4K while collecting Neutron diffraction data. The use a standard NIR reflection probe and modification of the cryostat sample stick allows the probe to be introduced into the cryostat. A second spectrometer is available for UV-Vis spectroscopy and can be used in a similar method. These spectrometers are also available for use on other scattering instruments over a limited temperature range.
- ItemAustralian centre for neutron scattering: sample environment report(Australian Institute of Nuclear Science and Engineering (AINSE), 2018-11-19) Manning, AG; Wakeham, D; Davidson, G; Booth, N; Imperia, P; White, R; Lee, S; D'Adam, TMIn the past 2 years since the 2016 AANSS symposium, the sample environment group of the Australian Centre for Neutron Scattering (ACNS) has continued to facilitate neutron experiments and expand sample environment capability. This report will present the current sample environment and laboratory facilities and recent developments. We have made progress in light irradiation and spectroscopy developments; on a new temperature controlled multi-sample changer with tumbling capability; on a rotational PE Cell; and on new sample probes made from composite materials. Other improvements include new high pressure couplings for helium compressors and modifications to a dilution insert to allow larger samples and use in other cryostats extending the capability. Ongoing major projects are a new superconducting split-coil magnet dedicated to SANS and TOFPAS, two new cryostats (1.5 K to 800 K temperature range) with the aim of halving the system and sample cooling time and a new dilution fridge that will allow top-loading of samples and the ability to take much larger samples than the existing dilution insert. There have also been staffing changes with previous Sample Environment Group Leader, Paolo Imperia moving into the Operations Manager position. The new group leader, Rachel White, was recently appointed. Our Laboratory Manager, Deborah Wakeham, joined us in July 2017. © The Authors.
- ItemCalibration of temperature controllers and sensors(Australian Institute of Nuclear Science and Engineering, 2016-11-29) Manning, AG; Booth, N; Imperia, PReliable temperature measurements are a key part of many sample environment setups for neutron scattering experiments. This typically requires the use of both a temperature sensor and temperature controller. It is often desirable to be able to perform a continuous measurement spanning a wide range of temperatures, however the choice of suitable sensors is limited. Rhodium iron (RhFe) resistive thermometers are best suited to the temperature range of our cryofurnaces (1.5 to 800 K), however their calibration is known to drift when exposed to elevated temperatures. Here, we will present procedures to ensure that both the controller and sensor used in such experiments are performing optimally. Calibrated resistors, which can mimic the behavior of a temperature sensor fixed at a particular temperature, can be used to check the calibration of the readings given by temperature controllers such as Lake Shore 336/340 or Oxford Instruments iTC units. If the controllers are known to be operating to the tolerances specified by their manufacturer, then we can have confidence in the measurements that they make. We can then use our newly verified controllers to assess the performance of RhFe sensors over a range of temperatures from 4 to 800 K in a custom-built calibration rig. This allows us to quantify the behavior of the sensors after they are subject to high temperatures, and to account for shifts in their readings. Using this procedure, we can ensure that the sensors remain reliable after prolonged operational use.
- ItemA fast-cooling sample-positioning probe for low-temperature neutron scattering experiments(Wiley, 2020-01-14) Manning, AG; Avdeev, M; Imperia, PTop-loading exchange gas cryostats have for a long time been a widely used sample environment device for a variety of neutron scattering experiments. In particular, they allow for simpler and faster changes of samples mounted on sample-positioning probes than is possible with bottom-loading cryostats under vacuum. Here, a new design for sample probes using composite materials is investigated, which significantly decreases the time required to cool a newly installed sample in two different types of closed-cycle exchange gas cryostat. © 1999-2021 John Wiley & Sons, Inc.
- ItemIntegration of polarised 3He infrastructure with sample environment equipment(Australian Institute of Physics, 2017-01-31) D'Adam, TM; Booth, N; Davidson, G; Lee, S; Manning, AG; Timperon, N; Imperia, PMany challenges exist when attempting to integrate polarised 3He infrastructure with neutron beam instruments. This is often due to its sensitivity to the magnetic environment and also due to the compact geometry of many beam lines. One additional consideration is the effect that Sample Environment equipment can have on the functionality of a particular polarised neutron setup. We have been able to provide incident beam polarisation with two separate magnets providing fields at the sample position of up to 2 T. In addition, full polarisation analysis is possible over a temperature range of 30 mK to 800 K. To enable this, some pieces of Sample Environment equipment must be designed specifically for use with polarised 3He and in many cases modifications are necessary to accommodate the sensitive gas. We are also in the process of procuring an 8 T shielded asymmetric magnet suitable for use with polarised 3He infrastructure.
- ItemNew sample environment projects and developments at the Australian Centre for Neutron Scattering(Australian Institute of Physics, 2019-02-05) White, R; Imperia, P; Booth, N; D'Adam, TM; Davidson, G; Lee, S; Manning, AG; Tobin, SSince the 2018 meeting the sample environment team at the Australian Centre for Neutron Scattering (ACNS) has progressed the design and construction of the new superconducting split-coil magnet, a fast cooling closed cycle cryostat and a new type of closed cycle dilution refrigerator. The first of the two fast cooling cryostats (compact closed cycle dry cryostats, 1.5 K to 800 K) will arrive in early 2019, with a tested sample cool down of 30 minutes. The new magnet is in the final stages of design, including a sample well for our time-of-flight spectrometer PELICAN. The new magnet will have active magnetic shielding and an asymmetric coil design to allow experiments with polarised neutrons. The expected arrival for the magnet is mid-2019. The closed cycle dilution refrigerator will have high cooling power and a very large sample space allowing a new class of experiments with neutrons at ultra-low temperature, arriving in March 2019. Also presented is the development of carbon fibre sample probes to enable faster cooling and quicker sample changes.
- ItemNew sample environment projects and developments at the Australian Centre for Neutron Scattering(International Conference on Neutron Scattering, 2017-07-12) Imperia, P; Booth, N; D'Adam, TM; Davidson, G; Lee, S; Manning, AGThe sample environment team at the Australian Centre for Neutron Scattering (ACNS) has been recently awarded funding for a new superconducting split-coil magnet, a fast closed cycle cryostat and a closed cycle dilution refrigerator of the latest generation. The new magnet design is of particular interest; the brief is complicated by the request to serve two separate classes of instruments: small angle scattering and time of flight. The magnet will have low fringe field, active shield design, and specific requirements for the asymmetric field gradient to allow experiments with polarised neutrons. Low fringe field values are combined with a minimum central field of 7 Tesla, wide “clean” scattering angle and dimensional and weight constraints. The design challenges and possible solutions will be detailed, together with a time frame for delivery and commissioning. The new compact closed cycle cryostat (1.5 K to 800 K) with a small He dump, aims to halve the system and sample cooling time, generating performances comparable to that of wet type “orange” cryostats without the necessity to refill with cryogenic liquids. The closed cycle dilution refrigerator will have high cooling power and large sample space, allowing new class of experiments with neutrons at ultra-low temperature. The most recent equipment built in-house and unique to the ACNS, such as the Peltier sample changer and the thermalised sample tumblers for SANS and USANS, will also be discussed.
- ItemNew sample environment projects and developments at the Australian Centre for Neutron Scattering.(Australian Institute of Physics, 2018-01-30) Imperia, P; Booth, N; D'Adam, TM; Davidson, G; Lee, S; Manning, AG; Tobin, S
- ItemPolarised neutron capabilities at ACNS(Australian Institute of Nuclear Science and Engineering (AINSE), 2020-11-11) Manning, AGThe Australian Centre for Neutron Scattering offers neutron spin filters for six instruments (WOMBAT, PELICAN, QUOKKA, PLATYPUS, TAIPAN and SIKA), using a combination of supermirrors and polarised 3He cells. The infrastructure required to use 3He spin filters is particularly complicated, and a clear understanding of this is pivotal to designing and carrying out successful experiments which take advantage of polarised neutron scattering. Such experiments typically investigate systems where detailed study of magnetic effects or the separation of coherent and incoherent scattering is needed. Here, the capabilities for polarised neutron scattering experiments for each of these instruments are summarised, including compatible sample environments such as cryostats, magnets and sample changers, and a discussion of key considerations when planning experiments using polarised neutrons. A newly-acquired 7 tesla compensated vertical magnet will also be described, and some initial results for its use on the SANS instrument QUOKKA will be presented. Finally, some possible future directions to further develop the polarised neutron capabilities at ACNS are outlined. © The author.
- ItemPolarised neutron scattering experiments at the Australian Centre for Neutron Scattering(Australian Institute of Physics, 2022-12-11) Manning, AGNeutron scattering is a powerful tool for investigating a variety of condensed-matter systems, and using spin-polarised neutrons reveals further unique information. The possibilities for performing scattering experiments with polarised neutrons at the Australian Centre for Neutron Scattering will be outlined.
- ItemThe recent progress of polarized neutron scattering techniques at SIKA(Australian Nuclear Science and Technology Organisation, 2021-11-26) Yano, SC; Deng, GH; Rule, KC; de Souza, NR; Manning, AG; Peng, H; Wu, CMSIKA, the cold-neutron triple-axis spectrometer is on the CG4 beam port at the OPAL reactor, ACNS, ANSTO. We have reported the capabilities and status of SIKA in the last several user's meetings. In this meeting, we discuss the recent development of polarized neutron scattering experiments on SIKA. A 3He polarization analysis system is available for SIKA. We have performed several user experiments and commissioning experiments in the last two years. We would like to present some results by introducing the techniques we are trying to implement. In addition, we discuss our plan for the polarized neutron scattering experiment on the SIKA. © The Authors
- ItemUpdate on polarised neutron capabilities at the Australian Centre for Neutron Scattering(Australian Nuclear Science and Technology Organisation, 2021-11-24) Manning, AG; Sokolova, AVThe Australian Centre for Neutron Scattering offers neutron polarisation capabilities which are compatible with six different neutron scattering instruments, using a combination of polarising supermirrors and 3He cell spin filters. An overview of these capabilities will be given, followed by a description of some recent experiments which make use of a variety of these capabilities on instruments, including the cold triple-axis spectrometer Sika, and the small-angle neutron scattering instrument Quokka with a recently-commissioned 7 T compensated vertical magnet. Finally, current and future work to expand capabilities will be outlined, such as a new system for polarisation analysis experiments with magnetic … © 2021 The Authors