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    Stability of charge-stripe ordered La2−xSrxNiO4+δ at one third doping
    (Elsevier, 2018-05) Freeman, PG; Mole, RA; Christensen, NB; Stunault, A; Prabhakaran, D
    The stability of charge ordered phases is doping dependent, with different materials having particularly stable ordered phases. In the half filled charge ordered phases of the cuprates this occurs at one eighth doping, whereas in charge-stripe ordered La2−xSrxNiO4+δ there is enhanced stability at one third doping. In this paper we discuss the known details of the charge-stripe order in La2−x SrxNiO4+δ, and how these properties lead to the one third doping stability. © 2017 Elsevier B.V.
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    The magnetic properties of single-crystalline atacamite, Cu2Cl(OH)3
    (Elsevier, 2018-05-01) Heinze, L; Beltran-Rodriguez, R; Bastien, G; Wolter, AUB; Reehuis, M; Hoffmann, JU; Rule, KC; Süllow, S
    We present susceptibility measurements on the natural mineral atacamite, Cu2Cl(OH)3, for the first time along the three crystallographic axes. Further, we have carried out an elastic neutron diffraction experiment which shows that the symmetry of the magnetic ground state of atacamite is described by a propagation vector q=(1/2 0 1/2). © 2017 Elsevier B.V.
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    A fast switching electrostatic deflector system for actinide isotopic ratio measurements
    (Elsevier, 2010-04) Zorko, B; Child, DP; Hotchkis, MAC
    We have implemented a fast switching electrostatic system on the actinides beamline on the ANTARES accelerator at ANSTO, to improve the precision of analyses by accelerator mass spectrometry. This high-energy bouncing system is based on a pair of deflector plates, deflecting in the orbit plane, set at the entrance and exit of the analysing magnet. The design of deflector plates is unique, and it was modelled by SIMION in order to minimize field inhomogenity and fringe field effects. The pair of deflector plates are supplied by a high-voltage amplifier driven by an EPICS-enabled control unit, with two 4 W power supplies providing up to ±10 kV modulation. The high-energy bouncing system is synchronized with the existing low-energy bouncing system. To measure the isotopic ratio with the new system, the magnetic fields of the injector and analysing magnets are set to transmit selected isotopes along the beam line with zero voltage applied. The other isotopes of interest are transmitted by keeping the magnetic fields constant and modulating the voltages on the injector magnet chamber and on the high-energy deflector plates. © 2009 Elsevier B.V.
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    Time dependent fast neutron background: understanding the cause and identifying a solution for the PELICAN cold neutron spectrometer
    (Elsevier, 2018-12) Elcombe, MM; Mole, RA; Yu, DH
    During the commissioning phase of the cold neutron chopper spectrometer PELICAN at ANSTO, a strong pulsed fast neutron background in-phase with the slave chopper has been observed. Through a series of diagnostic measurements the major components of this background have been identified. The fast neutrons are generated by photoneutron production in the Be filter as a secondary process to γ production during neutron absorption. The Be filter has been modified to minimise the fast neutron generation. Ultimately, the time dependent background has been completely removed by phasing two Fermi choppers, instead of using a Be filter to remove high order reflections from the monchromator. © 2017 Elsevier B.V.
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    Machine learning techniques to determine elemental concentrations from raw IBA spectra
    (Elsevier, 2024-01) Cohen, DD; Crawford, J
    For many decades we have run MeV protons beams together with four IBA spectra simultaneously to obtain over 35 different elemental concentrations on any given target. These include PESA for hydrogen, RBS for carbon, nitrogen and oxygen, PIXE for aluminium to lead and PIGE for light elements like fluorine, sodium and aluminium. As part of a machine learning process we have taken five years of monthly raw spectra for each of the four IBA techniques and used the R code subroutine XgBoost and the corresponding calculated elemental concentrations from iBAT analysis code to train the system. This system training included 35 different elemental species. We then used the system to predict the elemental concentrations, from just the next six months of raw IBA spectra with no other inputs. The results were excellent for all elemental concentrations above their minimum detection limits. Crown Copyright © 2023 Published by Elsevier B.V.