Tasks & Partners

Task 21.2.1 Gas handling & pressure cells for inert gases

High-pressure research is one of the fastest-growing areas of natural science, and one that attracts such diverse communities as those of physics, bio-physics, chemistry, materials science and earth sciences. In condensed matter physics there are a number of highly topical areas such as quantum criticality, pressure-induced superconductivity or non-Fermi liquid behaviour, where pressure is a fundamental parameter. An increase in the range of available pressures up to 10kbar will make a significant impact on the range of science possible. However, high pressure gas sample cells require thick cell walls which may lead to an unacceptable neutron background and thus the choice of materials and geometries is critical to improving the quality of the data. Reliable, safe and userfriendly high pressure gas handling systems are also an essential part of the development. This task will provide extended access to the temperature-pressure phase space and will benefit many areas of study.

Task 21.2.2 H2 gas handling & pressure cells

Hydrogen is seen as a clean and potentially plentiful energy source. The search for compounds that are capable of storing enough hydrogen and materials which could be used in efficient fuel cells is now an international priority. Due to the high sensitivity to hydrogen, neutron scattering is particularly suitable for the investigation of promising materials for hydrogen technology, under extreme conditions such as high temperatures and pressures. However, these conditions require sophisticated gas handling systems and special sample cells. The development of cells for high pressure hydrogen is made difficult by the embrittlement of construction materials, and at present our knowledge of material behaviour in the presence of hydrogen is limited. Thus part of this task will be research on suitable cell materials and technologies. This tasks aims to extend the pressure

NMI3 – Proposal number 226507 – Drafting date: 24/11/08 Page | 119 and temperature range of cells available at the facilities.

Studies of the liquid state are not only significant from a fundamental point of view but also represent important technological interests. The molten state is an essential stage in various industrial processes such as glass making, semi-conductor technology and the iron and steel making industry. However, the study of structure and dynamics in liquid metals or dielectric materials is often prevented by the chemical reaction of the high temperature melt with its sample holder. The development of two types of levitation system will offer greater access to these temperature ranges across a wider range of materials.

Task 21.3.1 – Construction of an ultra-high temperature aerodynamic levitation furnace, dedicated to neutron scattering and including conductivity measurements

The aim of this task is to design and build a furnace using aerodynamic levitation for reaching temperatures up to 3000 K, combined with conductivity measurements. We propose to build a furnace which can be installed on an instrument in a few hours. We also propose to design it so that it is compatible with the use of polarised beams, with the aim of investigating magnetic systems.

Task 21.3.2 – Ultra-high temperature furnace using electromagnetic/static levitation

The ultra-high temperature range can also be achieved by the use of an electromagnetic (EML) or an electrostatic (ESL) levitation apparatus which allows container-less processing of samples. The design of the EML furnace for liquid metals will be based on the prototype developed and built by the DLR in Cologne and could be adapted to dielectric materials by using an ESL system. We will develop and build a user-friendly and fully automatic EML/ESL levitation furnace.

The measurement of hydrogen storage materials, as well as the characterisation of chemical and catalyst reactions in porous materials, is of significant interest. All facilities have some capability to work in this area but the aim of this task is to significantly extend this to allow real-time in-situ measurements of many diverse chemical and physical phenomena. We plan to start by developing a volumetric low pressure (<1.5 bar) gas adsorption measurement system for experiments in an Orange cryofurnace (1.5-600 K) and, alternatively, in a cryogen-free miniature pulse tube refrigerator (50-600 K). These systems will then be enhanced by further developments to extend the temperature and pressure ranges up to 300 bar at 200°C. The gas control systems will also be increased to provide mass spectroscopy and constant pressure and flow conditions. Finally, a system with a magnetic gravimetric system with a pressure range up to 100 bar and a temperature range up to 500°C will also be delivered.