Paolo Imperia

Powder sample-positioning system for neutron scattering allowing gas delivery in top-loading cryofurnaces

A system for positioning powder samples in top-loading cryofurnaces during neutron scattering experiments, while facilitating the successive delivery of gas doses at set temperatures to the sample, has been designed and tested. The positioning system is compatible with a Hiden Isochema IMI instrument as a gas-dosing platform, enabling gases to be delivered to the sample through a centrally located and thermally stabilized capillary line and valve. The positioning system separates into an upper and a lower section, with the lower section enabling the sample to be isolated and inserted into a glove box. This work describes the system using example neutron powder diffraction results obtained with this system in closed-cycle cryofurnaces.

QUOKKA, the pinhole small-angle neutron scattering instrument at the OPAL Research Reactor, Australia: design, performance, operation and scientific highlights

QUOKKA is a 40 m pinhole small-angle neutron scattering instrument in routine user operation at the OPAL research reactor at the Australian Nuclear Science and Technology Organisation. Operating with a neutron velocity selector enabling variable wavelength, QUOKKA has an adjustable collimation system providing source–sample distances of up to 20 m. Following the large-area sample position, a two-dimensional 1 m2 position-sensitive detector measures neutrons scattered from the sample over a secondary flight path of up to 20 m. Also offering incident beam polarization and analysis capability as well as lens focusing optics, QUOKKA has been designed as a general purpose SANS instrument to conduct research across a broad range of scientific disciplines, from structural biology to magnetism. As it has recently generated its first 100 publications through serving the needs of the domestic and international user communities, it is timely to detail a description of its as-built design, performance and operation as well as its scientific highlights. Scientific examples presented here reflect the Australian context, as do the industrial applications, many combined with innovative and unique sample environments.

Sample environments at the Bragg Institute neutron scattering facility at ANSTO

Volume 27 • Number 2 • 2016 Neutron News 22 The nature of providing sample environment equipment and support is constantly evolving, as new technologies and experimental techniques are developed. To remain at the cutting edge of neutron scattering experiments, signifi cant improvements to sample environment facilities are demanded to expand the scope of investigations possible. Here we discuss a range of advancements made by the sample environment group at the Bragg Institute at ANSTO which highlights improvements to the control of temperature, electric and magnetic fi elds, pressure, gas and vapour delivery, spectroscopy, calorimetry, and combinations thereof.

2nd Asia-Oceania Instrument Scientist Workshops, Manly, July 19, 2015

Volume 26 • Number 4 • 2015 Neutron News 12 imaging was utilized to investigate position-dependent crystal information. Two presentations were held in the sessions on resonance absorption and four presentations on polarized neutron imaging techniques, respectively. Topics on interference effects, beam inhomogeneity and hardening effects, and software development were also provided. For all presentations, at least 30 minutes was allocated to promote intensive discussions, following the main purpose of this workshop series (see Figure 2). On the last day, participants visited that intense pulsed neutron facility at the MLF of J-PARC. Since the MLF was not in operation at the time, the visitors could access even inside the facilities at the beam lines, and detailed explanations were given by each beam line scientist. The next workshop, NEUWAVE-8, will be held in 2016 in Oxfordshire, UK.

The 8th International Workshop on Sample Environment, October 12–16, 2014, Oxfordshire, UK

Volume 26 • Number 2 • 2015 Neutron News 4 and the Old City of Jakarta. Overall, the School has helped those attending young scientists to build expertise and confi dence in the application of neutron scattering techniques, include in extending the networking with X-ray synchrotron scientists in Thailand. We would like to thank all lecturers and tutors for their generous efforts in stimulating the interests of the students; as well as IUCr, IAEA, AONSA, and BATAN for their fi nancial assistance provided to attending students and lecturers.

ANSTO hosted the 7th International Sample Environment Workshop

Volume 24 • Number 1 • 2013 Neutron News 12 T 7th international Sample Environment workshop was held in Sydney, September 17 to 20, 2012. Hosted by ANSTO, Bragg Institute, it has been for the fi rst time outside the United States and Europe. This biennial meeting, initially organised by Michael Meissner (Hahn-Meitner-Institute Berlin, now Helmholtz Zentrum Berlin, HZB) to foster collaboration between European neutron scattering facilities, has developed as a truly international event with delegates from America, Europe, Asia and Oceania. The aim and objective of this workshop series is to encourage and foster engineering best practice and technical exchanges between the scientists, engineers and technicians working with the Sample Environment at neutron scattering facilities around the world. The peculiarity of these meetings is the eclectic mesh of people of different background including relevant industrial representatives. The workshop this year has been characterized by the fi rst time presence of Pfeiffer Vacuum (Germany) through Sebastian Oberbeck, chief engineer of the roughing pumps development sector, who gave a technical review of recent progresses in vacuum technology discussing design details and customer necessities. The neutron scattering community is very small with respect to the semiconductor industry; however, the participation of Pfeiffer Vacuum gave us a chance to glimpse future developments and make our requirements known, for example, regarding helium tight and He-recirculating pumps. Oxford Instruments (UK), represented by John Burgoyne and Dinah Parker, and Hiden Isochema (UK), represented by Darren Broom, have also been part of the program delivering excellent presentations on recent developments and future trends in cryogenic and magnetism, gas delivery and sorption, respectively. In his opening of the workshop, Rob Robinson, head of the Bragg Institute, underlined the invaluable contribution of sample environment groups to the success of scientifi c experiments. The continuous progress in sample environment equipment and operation is also realised by inviting technical staffs from different neutron scattering facilities to these bi-annual meetings to share their work experience, tricks of the trade and to forge bonds aimed at improving the users’ experience and therefore increasing the facilities’ productivity. Several participants expressed the great value of this connectedness. True newcomers, as well as the more experienced groups can call friends on the other side of the world for a helping hand. Problems and solutions, minutia of everyday grind and future developments have been openly and intensely discussed in a collaborative and friendly way, during the 35 talks and the 14 posters, in 12 sessions and during coffee and lunch breaks that provided an informal exchange forum. There is a competition to offer “the best” user service and most reliable equipment and there is the camaraderie of being on the same boat facing the same sort of challenges. Moreover, the workshop has been an ideal ground to look ahead to the science and future challenges for specialised sample environments coming to our facilities. Particularly welcomed have been the talks of two distinguished scientists, Duncan McGillivray, University of Auckland, ANSTO hosted the 7th International Sample Environment Workshop