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  • richardmitnick 7:38 am on April 13, 2018 Permalink | Reply
    Tags: , Neutron diffraction helps unlock the secrets of ice, Pearl diffractometer, , UK’s ISIS Neutron and Muon Source, University College London   

    From UCL viaSTFC: “Neutron diffraction helps unlock the secrets of ice” 

    UCL bloc

    University College London


    STFC

    1
    A schematic drawing of the upgraded Pearl diffractometer showing the 90 degrees and low angle detectors. (Credit: STFC).

    11 April 2018

    New research undertaken by scientists using the UK’s ISIS Neutron and Muon Source is improving our understanding of the highly unusual properties of ice and this knowledge will be of importance to any future study where ice coexists with other materials in nature, for example on icy moons such as Jupiter’s Europa.

    Although water is one of the most common elements, the complex properties of water and particularly ice are not well understood. There are many forms of ice, which are completely different to the ice you would find in a freezer.

    As water freezes its’ molecules rearrange themselves, and high pressure causes the molecules to rearrange in different ways than they normally would. The many distinct phases of ice can be explained using a phase diagram, which shows the preferred physical states of matter at different temperatures and pressures.

    Researchers from University College London (UCL) and STFC’s ISIS Neutron and Muon Source have used the PEARL high pressure neutron diffractometer at ISIS to investigate the impact of ammonium fluoride impurities on water’s phase diagram.

    The scientists discovered that the addition of this impurity caused a particular phase of ice, known as ice II, to completely disappear from water’s phase diagram whereas the other phases were unaffected.

    The many different phases of ice can be grouped into one of two types – hydrogen-ordered phases and hydrogen-disordered phases. In these different phases the orientation of water molecules is either firmly defined or disordered.

    Ice II is a hydrogen-ordered phase of ice that forms under conditions of high pressure. Unlike other phases of ice, ice II remains thermodynamically stable and hydrogen-ordered up to very high temperatures and the origin of this anomalous result is not well understood.

    Dr Christoph G. Salzmann, UCL said: “Without in-situ neutron diffraction we could not have performed this study. It was paramount to demonstrate that ice II has disappeared in the region of the phase diagram where it would normally exist.”

    “Unlike the other phases the water molecules in ice II interact with each other over very long distances. In a sense, whatever happens to one water molecule in a crystal of ice II – the effect is “felt” by all other molecules. In our study, ice II experiences a disturbance by the ammonium fluoride which destabilizes all of the ice II and makes it disappear.”

    This observation allowed researchers to infer important information on the highly unusual properties of ice II and the special properties of ice II provide a new explanation as to why the phase diagram of water displays so many anomalies, including liquid water.

    The results have been published in Nature Physics.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    STFC Hartree Centre

    Helping build a globally competitive, knowledge-based UK economy

    We are a world-leading multi-disciplinary science organisation, and our goal is to deliver economic, societal, scientific and international benefits to the UK and its people – and more broadly to the world. Our strength comes from our distinct but interrelated functions:

    Universities: we support university-based research, innovation and skills development in astronomy, particle physics, nuclear physics, and space science
    Scientific Facilities: we provide access to world-leading, large-scale facilities across a range of physical and life sciences, enabling research, innovation and skills training in these areas
    National Campuses: we work with partners to build National Science and Innovation Campuses based around our National Laboratories to promote academic and industrial collaboration and translation of our research to market through direct interaction with industry
    Inspiring and Involving: we help ensure a future pipeline of skilled and enthusiastic young people by using the excitement of our sciences to encourage wider take-up of STEM subjects in school and future life (science, technology, engineering and mathematics)

    We support an academic community of around 1,700 in particle physics, nuclear physics, and astronomy including space science, who work at more than 50 universities and research institutes in the UK, Europe, Japan and the United States, including a rolling cohort of more than 900 PhD students.

    STFC-funded universities produce physics postgraduates with outstanding high-end scientific, analytic and technical skills who on graduation enjoy almost full employment. Roughly half of our PhD students continue in research, sustaining national capability and creating the bedrock of the UK’s scientific excellence. The remainder – much valued for their numerical, problem solving and project management skills – choose equally important industrial, commercial or government careers.

    Our large-scale scientific facilities in the UK and Europe are used by more than 3,500 users each year, carrying out more than 2,000 experiments and generating around 900 publications. The facilities provide a range of research techniques using neutrons, muons, lasers and x-rays, and high performance computing and complex analysis of large data sets.

    They are used by scientists across a huge variety of science disciplines ranging from the physical and heritage sciences to medicine, biosciences, the environment, energy, and more. These facilities provide a massive productivity boost for UK science, as well as unique capabilities for UK industry.

    Our two Campuses are based around our Rutherford Appleton Laboratory at Harwell in Oxfordshire, and our Daresbury Laboratory in Cheshire – each of which offers a different cluster of technological expertise that underpins and ties together diverse research fields.

    The combination of access to world-class research facilities and scientists, office and laboratory space, business support, and an environment which encourages innovation has proven a compelling combination, attracting start-ups, SMEs and large blue chips such as IBM and Unilever.

    We think our science is awesome – and we know students, teachers and parents think so too. That’s why we run an extensive Public Engagement and science communication programme, ranging from loans to schools of Moon Rocks, funding support for academics to inspire more young people, embedding public engagement in our funded grant programme, and running a series of lectures, travelling exhibitions and visits to our sites across the year.

    Ninety per cent of physics undergraduates say that they were attracted to the course by our sciences, and applications for physics courses are up – despite an overall decline in university enrolment.

    UCL campus

    UCL was founded in 1826 to open up higher education in England to those who had been excluded from it – becoming the first university in England to admit women students on equal terms with men in 1878.

    Academic excellence and research that addresses real-world problems inform our ethos to this day and are central to our 20-year strategy.

     
  • richardmitnick 8:34 am on March 1, 2018 Permalink | Reply
    Tags: , Gamma-ray laser, , , , University College London, University of Jyväskylä Accelerator Laboratory Finland, University of Surrey   

    From STFC: “UK researchers take a very cool step towards a gamma-ray laser” 


    STFC

    28 February 2018

    Wendy Ellison
    Science and Technology Facilities Council
    Tel: 01925 603232
    wendy.ellison@stfc.ac.uk

    1
    The dedicated beamline ready for UK experiments to produce the world’s first coherent gamma rays at the University of Jyväskylä in Finland. (Credit: UCL).

    UK scientists are poised to test a new technology that could bring the gamma-ray laser out of science fiction and into reality.

    The gamma-ray laser was once described as one of the thirty most important problems in physics. Much discussed, it would herald a new generation of technology for research and industry, with enhanced applications that could range from spacecraft propulsion, to cancer treatment, ultra-precise imaging techniques, and the security sector.

    A key stepping stone in making the gamma-ray laser possible is the ability to produce coherent gamma-ray emissions. A long standing challenge since lasers were first invented in 1960, coherent gamma-ray emissions have been considered an almost impossible task, until now.

    In a research project funded by STFC, a UK team of researchers from University College London and the University of Surrey have combined their advanced atomic and nuclear physics expertise to conceive a proposal that will experimentally demonstrate that producing coherent gamma-ray emissions is a real possibility. The proposal, arguably the first of its kind, is testable in a realistic way that has never been considered before. It will seek to overcome a number of fundamental problems which have hindered the realisation of a gamma-ray laser. Until now, other proposals either have been testable only in principle, or would require technologies not yet available. The approach of the UCL and Surrey team is instead achievable with current technology. Full details of this fascinating research have been published in Physics Letters B.

    Professor Phil Walker, Professor of Physics at the University of Surrey, said: “It is thanks to recent advances in our ability to make ultra-cold gases, and also in our understanding about the way that nuclei in specific gasses can behave so uniquely, that we have been able to even consider that such an exciting and potentially game-changing experiment could be possible. We could be on our way to being one step closer to solving one of the most challenging problems in physics.”

    This research is no longer just theory. UCL’s Professor of Physics, Professor Ferruccio Renzoni, and his team are now busy setting up an experiment at the University of Jyväskylä Accelerator Laboratory in Finland. Key components, assembled at UCL, are already in place in Finland at the experimental facility. There, a cyclotron particle accelerator will produce the unstable caesium, and the UCL’s laser system will trap and cool it to 100 nano-kelvin, with a view to successfully producing the world’s first coherent gamma-ray emissions.

    Professor Ferruccio Renzoni said: “If the project goes as planned, our experiment in Finland will show that it is possible to produce coherent gamma radiation in this way, and will lead on to further tests that will confirm the best conditions for scaling up to make a practical device, the gamma-ray laser, over the coming years. In the meantime, several milestones in atomic physics and new insights in nuclear behaviour will be available for us to study.”

    Professor John Simpson, Head of STFC’s Nuclear Physics Group, said: “Here in the UK we are making exciting progress in the world’s quest to develop the technology that will make a gamma-ray laser possible. The social and economic benefits of such technology will be dramatic. I look forward to the results that the UK research team will achieve with their international collaborators at Jyväskylä in Finland.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    STFC Hartree Centre

    Helping build a globally competitive, knowledge-based UK economy

    We are a world-leading multi-disciplinary science organisation, and our goal is to deliver economic, societal, scientific and international benefits to the UK and its people – and more broadly to the world. Our strength comes from our distinct but interrelated functions:

    Universities: we support university-based research, innovation and skills development in astronomy, particle physics, nuclear physics, and space science
    Scientific Facilities: we provide access to world-leading, large-scale facilities across a range of physical and life sciences, enabling research, innovation and skills training in these areas
    National Campuses: we work with partners to build National Science and Innovation Campuses based around our National Laboratories to promote academic and industrial collaboration and translation of our research to market through direct interaction with industry
    Inspiring and Involving: we help ensure a future pipeline of skilled and enthusiastic young people by using the excitement of our sciences to encourage wider take-up of STEM subjects in school and future life (science, technology, engineering and mathematics)

    We support an academic community of around 1,700 in particle physics, nuclear physics, and astronomy including space science, who work at more than 50 universities and research institutes in the UK, Europe, Japan and the United States, including a rolling cohort of more than 900 PhD students.

    STFC-funded universities produce physics postgraduates with outstanding high-end scientific, analytic and technical skills who on graduation enjoy almost full employment. Roughly half of our PhD students continue in research, sustaining national capability and creating the bedrock of the UK’s scientific excellence. The remainder – much valued for their numerical, problem solving and project management skills – choose equally important industrial, commercial or government careers.

    Our large-scale scientific facilities in the UK and Europe are used by more than 3,500 users each year, carrying out more than 2,000 experiments and generating around 900 publications. The facilities provide a range of research techniques using neutrons, muons, lasers and x-rays, and high performance computing and complex analysis of large data sets.

    They are used by scientists across a huge variety of science disciplines ranging from the physical and heritage sciences to medicine, biosciences, the environment, energy, and more. These facilities provide a massive productivity boost for UK science, as well as unique capabilities for UK industry.

    Our two Campuses are based around our Rutherford Appleton Laboratory at Harwell in Oxfordshire, and our Daresbury Laboratory in Cheshire – each of which offers a different cluster of technological expertise that underpins and ties together diverse research fields.

    The combination of access to world-class research facilities and scientists, office and laboratory space, business support, and an environment which encourages innovation has proven a compelling combination, attracting start-ups, SMEs and large blue chips such as IBM and Unilever.

    We think our science is awesome – and we know students, teachers and parents think so too. That’s why we run an extensive Public Engagement and science communication programme, ranging from loans to schools of Moon Rocks, funding support for academics to inspire more young people, embedding public engagement in our funded grant programme, and running a series of lectures, travelling exhibitions and visits to our sites across the year.

    Ninety per cent of physics undergraduates say that they were attracted to the course by our sciences, and applications for physics courses are up – despite an overall decline in university enrolment.

     
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