ECHIDNA: a decade of high-resolution neutron powder diffraction at OPAL

Abstract

The ECHIDNA high‐resolution neutron powder diffractometer at the 20 MW OPAL research reactor in Australia produces high‐quality data for a broad spectrum of crystal and magnetic structural studies. The paper presents an overview of the current status of the hardware, latest developments in data‐reduction software, statistics on instrument usage and the user programme, and instrument limitations.

Synthesis and Structural Determination of the Disordered Bixbyite Cu3‐xSb1+xO5.5+3x/2 with Spin‐Glass Behaviour

“…The beam accelerating potential was 20 kV. Neutron powder diffraction (NPD) data were collected on the high‐resolution powder diffractometer ECHIDNA at the OPAL research reactor (ANSTO, Lucas Heights, Australia) . Approximately 2 grams of the sample were loaded in powder form into a cylindrical vanadium canister and NPD patterns were collected with neutrons having a wavelength of 1.6215 Å in the temperature range from 3.5 K to 1173 K. Measurements above room temperature of the sample were done in quartz tubes instead of vanadium canisters.…”

“…The beam accelerating potential was 20 kV.N eutron powder diffraction (NPD) data were collected on the high-resolution powder diffractometer ECHIDNA at the OPAL research reactor (ANSTO, Lucas Heights, Australia). [26] Approximately 2grams of the sample were loaded in powder form into ac ylindrical vanadium canister and NPD patterns were collected with neutrons having a wavelength of 1.6215 in the temperature range from 3.5 Kt o 1173 K. Measurements above room temperature of the sample were done in quartz tubes instead of vanadium canisters. The temperature-dependent magnetization of the samples was measured using aQ uantum Design Physical Properties Measurement System (PPMS) with av ibrating sample magnetometer (VSM) probe from 2 to 300 Ki na na pplied magnetic field 1kOe, under zero fieldcooled (ZFC) and field-cooled (FC) conditions.…”

Neutron Guide Building instruments of the Brazilian Multipurpose Reactor (RMB) project

“…Following these principles and the state-of-art diffractometer Echidna, SPODI, E9, and D2B, we predefine primary collimator between 5′ and 18′, secondary collimator between 10′ and 20′ and tertiary to be equal to 5′. We also assume a monochromator mosaicity around 33′, as that on Echidna instrument [15].…”

A fast-cooling sample-positioning probe for low-temperature neutron scattering experiments

“…Given that low-temperature neutron scattering experiments take about half of all ACNS beam-time, not only on the high-resolution powder diffractometer Echidna (Avdeev & Hester, 2018) but also across the entire facility (P. Imperia & R. White, personal communication), that provides a substantial improvement in efficiency in the long run as several hours could conceivably be saved during the course of a typical experiment involving multiple sample changes. While these probes have not proven to be considerably less durable than those constructed from stainless steel, it is easy to replace the different components of the new probes if they are damaged, making them suitable for the rigours of a user facility.…”

“…Several carbon-fibre sticks were manufactured in-house and have already been in use on neutron diffraction instruments Echidna and Wombat since 2018. Given that low-temperature neutron scattering experiments take about half of all ACNS beam-time, not only on the high-resolution powder diffractometer Echidna (Avdeev & Hester, 2018) but also across the entire facility (P. Imperia & R. White, personal communication), that provides a substantial improvement in efficiency in the long run as several hours could conceivably be saved during the course of a typical experiment involving multiple sample changes.…”