1.5 GPa compact double-wall clamp cell for SANS and NSE studies at low temperatures and high magnetic fields

Abstract

Abstract.We have developed and realised a compact high-pressure clamp cell of the piston-cylinder type for Small Angle Neutron Scattering (SANS) and Neutron Spin Echo (NSE) spectroscopy measurements. The cell can pressurise 5 mm samples up to 1.5 GPa. It is non-magnetic, produces a sufficiently low and flat SANS background with a relatively good neutron transmission and can be used in combination with polarised neutrons. The cell accommodates samples of up to 55 mm 3 in volume and adopts a two-layer geometry: a TiZr body (outer layer) and a CuBe2 insert (inner layer). Its design is very compact and can be employed inside cryomagnets featuring a sample bore greater than 30 mm. We present the cell and illustrate its performances with a series of neutron scattering experiments performed on single-crystalline MnSi.

Low-background materials for high pressure cells used in inelastic neutron scattering experiments

“…The diameter of NCA3 is Ø12.3 mm. The material of samples NCA1 and NCA3 has been used for producing the cell described in [18].…”

“…As a result, the main difficulty encountered in inelastic neutron scattering experiments is the issue of the neutron beam having to travel through rather thick sections of the pressure vessels which contain the sample under investigation [5,7]. This gives rise to unwanted absorption and coherent or incoherent background scattering which can be mitigated by the right choice of vessel material and the optimisation of a high-pressure vessel geometry design [8,18].…”

Clamp cells for high pressure neutron scattering at low temperatures and high magnetic fields at Heinz Maier-Leibnitz Zentrum (MLZ)

“…The pressure cell should also be non-magnetic down to very low temperatures to be used for polarized neutron scattering to reveal weak magnetism. Only a few high-strength materials satisfy these criteria [2][3][4].…”

“…The most common device for the high pressure neutron experiments is the clamp cell, also commonly used for magnetic measurements [2,[4][5][6][7]. Its characteristic feature is the application and fixation of the pressure ex situ, before the cell is transferred into the experimental setup.…”

“…diffraction, spectroscopy, etc. [2,4]. Although clamp cells have a relatively simple design, they have to be carefully optimized in order to reach the targeted pressure under the aforementioned requirements [2,8] for specific neutron facilities.…”