A high temperature high pressure cell for quasielastic neutron scattering

Area of Science:

• Materials Science
• Geophysics
• Neutron Scattering Physics

Background:

• Neutron scattering is a powerful technique for probing material dynamics.
• Studying materials under high temperature and high pressure is essential for geophysics and materials science.
• Existing equipment often has limitations in achieving extreme conditions or sample volume.

Purpose of the Study:

• To develop and present a novel high temperature, high pressure (HTHP) cell for neutron scattering experiments.
• To enable in-situ studies of material behavior under conditions relevant to geological processes.
• To improve the signal-to-noise ratio for quasielastic neutron scattering (QENS) measurements.

Main Methods:

• Design and construction of a HTHP cell using a water-cooled Niobium-Zirconium (Nb1Zr) alloy pressure cell body.
• Integration of an internal heating furnace to achieve extreme temperatures.
• Utilizing a sample volume of approximately 700 mm³ within the cell.

Main Results:

• The HTHP cell successfully reached temperatures up to 1500 K and pressures up to 200 MPa.
• The Nb1Zr material demonstrated suitable mechanical strength and favorable neutron scattering properties (low absorption and incoherent scattering).
• An acceptable signal-to-noise ratio of approximately 10:1 was achieved, facilitating meaningful QENS studies.

Conclusions:

• The developed HTHP cell significantly expands the capabilities for neutron scattering research.
• This new capability allows for unprecedented investigations into phenomena like water dynamics in silicate melts under relevant geological conditions.
• The HTHP cell opens new avenues for quasielastic neutron scattering on various spectrometers.