The large-volume high-pressure facility at GSECARS: A “Swiss-army-knife” approach to synchrotron-based experimental studies

Abstract A number of new techniques have been developed at the large-volume press (LVP) high-pressure facility at the GeoSoilEnviroCARS (GSECARS) sector of the advanced photon source (APS). This article describes the 10 MN (1000 T) and 2.5 MN (250 T) hydraulic presses in the insertion device (ID) and bending magnet (BM) beamlines, respectively, with several apparatus and various diffraction and imaging techniques developed since the inception of the facility. Several Kawai-type high-pressure modules, whose second-stage anvils range from 10 mm to 25.4 mm in edge lengths, are used in the hydraulic presses, with pressure ( P ) and temperature ( T ) capabilities up to 30 GPa and 3000 K. A DIA-type apparatus can be compressed in both presses for studies requiring large sample volumes. A deformation DIA (D-DIA) has been developed to allow controlled deformation studies on both crystalline and glass materials, using monochromatic diffraction and imaging, up to 20 GPa and 1800 K. A high-pressure tomography apparatus is available for conducting tomography studies at high P and T , with a typical spatial resolution of a few micrometers. Toroidal anvil modules provide large 2 θ angles for studies of non-crystalline materials, and a new large D-DIA module is under construction for double-stage megabar pressure generation as well as deformation on large samples with the capability of acoustic emission detection. The flexible design of the monochromator at the BM beamline makes it feasible to switch between monochromatic and white-beam mode during an experiment, ideal for monochromatic imaging studies (e.g., high- P tomography) with energy-dispersive diffraction for pressure measurements. A new angle-dispersive diffraction technique has been developed for high P – T crystallography studies, where a solid-state detector is step-scanned, thereby collecting a large number of angle-dispersive spectra over a wide range of photon energies recorded in the multi-channel analyzer. An ultrasonic interferometer is available and has been used in several high-pressure modules for acoustic velocity measurements. These unique features allow world-wide users to select the best experimental techniques for tackling a wide range of problems relevant to earth and planetary science, materials science, physics, and chemistry. Scientific highlights are provided and future improvements and prospects are discussed.