The SINE2020 Sample Environment WP: Interview with the coordinator Eddy Lelièvre-Berna
1. Standards for better instrument-SE communication We'll develop standards to facilitate the communication between the instrument control work station and the sample environment equipment. Currently, to be able to remotely control temperature, pressure or humidity during an experiment, scientists need to write pieces of code specific to the equipment available at each facility, as each facility does it differently. To tackle this issue we'll start by defining 2 standards: what we communicate and how we communicate it. 2. Making neutron SE more efficient We'll work towards an efficient sample environment for neutron research. One of the approaches is to improve the signal-to-background ratio in the detectors i.e. to reduce the background produced by the environment around the sample. For instance, by changing the diameter of a cryostat, one can reach an optimal diameter that reduces the background noise. We'll first develop software to simulate the equipment and thus have an estimate of the background it produces. Once we reach optimal dimensions, we'll modify our equipment, solve issues raised by new geometries and expect to improve the performance by as much as a factor of five in the signal-to-background ratio. We'll improve experiments by providing tools to facilitate them and reduce beam-time losses. For instance, when we insert a sample in the dilution fridge, cool it down, and connect the beam, we typically need 1/2day to reach the temperature we need. If we realise that we are misaligned by 3°C we have to warm-up the system, move the sample, re-align it… This process is very time consuming. Our aim is to have a remotely controlled goniometer(*) inside the dilution fridge, and speed up the process of cooling down samples in furnaces, as nowadays the samples take 2-3 hours to cool down before we are able to open the furnace. All these issues make experiments longer, so we are working on making the process more efficient. (*) Goniometer: tool that allows tilting the sample. 3. Next generation pressure cells for neutron and muon research We'll build a new generation of pressure cells from new materials and designed from novel geometries to boost the capabilities of neutron scattering and muon spectroscopy. The 1st step is to improve the piston cell for muon instruments because the current cell is difficult to use and there are a number of issues that need to be improved. The 2nd step is to design a high-pressure cell that we could use both in neutron and muon instruments. Another idea is to improve the vertical angular access to samples compressed in Paris-Edinburgh cells, as currently it is very difficult to reach the sample. Furthermore we would like to replace the anvils and the pressure-transmitting media by materials transparent to neutrons. The anvils currently used are absorbent to neutrons because it was created so that scientists could look at the sample alone. This however stops neutrons from reaching the sample. The pressure-transmitting media scatter neutrons and produce background that we would like to reduce. We will also look at ways to develop new clamp cells. Clamp cells are generally quite small and fit in high-field magnets. They are locked (or clamped) under pressure at the lab and transported to the beam for measurements. Our plan is to investigate whether we can have several layers of different materials. By using the technique of multi-layer geometry we can certainly improve the cell’s transparency and decrease the diffuse scattering of the cell. We'll develop a 700bar hydrogen container. Neutrons are suited for investigating hydrogen storage so we'll provide equipment for Industry's requests. 4. Complementary in-situ measurements for neutron and muon experiments For muons we'll build a cavity with a RF field that enables to explore chemical mechanisms. For neutrons we'll build a compact low-field NMR system sitting on a neutron beam for simultaneous diffusion coefficents measurement.
Keywords
neutrons, muons
Countries
Switzerland, Czechia, Germany, Spain, France, Sweden, United Kingdom
