Neutron Diffraction Experiments Research Articles

Neutron Diffraction Measurements of Residual Stresses for Ferritic Steel Specimens over 80 mm Thick

The maximum thickness for ferritic steel specimens’ residual stress measurements using neutron diffraction is known to be about 80 mm. This paper proposes a new neutron diffraction configuration of residual stress measurements for cases that are over 80 mm thick. The configuration utilizes a neutron beam with a wavelength of 1.55 Å diffracted from the (220) plane with a diffraction angle (2θ) of 99.4°. The reason for the deep penetration capability is attributed to the chosen wavelength having enough intensities due to the low cross-section near the Bragg edge and the reduced beam path length (~16 mm) reflected by the large diffraction angle. Neutron diffraction experiments with this configuration can decrease strain errors up to ±150 με, corresponding to a stress of about ±30 MPa.

Residual stress relief strategy in thick steel weldments via local induction heat treatment: Simulation and neutron diffraction experiment

This study investigated the effect of local induction post-weld heat treatment (PWHT) on residual stress relief in thick submerged arc welded steel plates. A combination of numerical and neutron diffraction methods was used to examine the effect of various PWHT parameters, such as annealing temperature and holding time, on the relief of residual stress in welded plates with various thicknesses. A sequentially coupled thermal–mechanical finite element model was used to calculate the residual stress distribution in welded AH36 steel plates before and after PWHT. The model was validated by comparing its predictions with the experimental measurements, and the results showed good agreement. The residual stress of the thick welded plates was effectively reduced via PWHT with local induction. The primary mechanism for this stress release was identified as stress relaxation caused by creep strain. Furthermore, a process map was established considering the PWHT conditions and plate geometry. This map provides a means of determining the optimal PWHT conditions to achieve desired stress reduction levels.

Magnetic structure of Tb[formula omitted]NbO[formula omitted] determined using neutron diffraction experiments and magnetic anisotropy calculations

We determined the magnetic structure of Tb3NbO7 based on powder neutron diffraction experiments and magnetic anisotropy calculations. We calculated the energy levels split by crystalline electric fields, and the magnetic moments using McPhase. The c axis is the easy axis for Tb1 moments, and magnetic anisotropy is small for Tb2 moments. Magnetic reflections were observed at low temperatures. The propagation vector is k1=(0,0,0) at 1.8 K and k2=(1/2,1/2,0) at 2.5 K between transition temperatures TN1=2.0 K and TN2=3.2 K. We selected candidates for an irreducible representation (IR) of the magnetic structures using magnetic anisotropy. From Rietveld refinements, we determined the following: The IRs are mΓ4 and mS2 at 1.8 K and 2.5 K, respectively. The main component of Tb1 ordered moments is w at 1.8 K. The order of the main components in each chain along the c axis is antiferromagnetic. Tb1 moments are disordered at 2.5 K. Tb2 moments form noncollinear magnetic structures in the ab plane perpendicular to Tb1 chains with a small w component at both the 1.8 K and 2.5 K. The magnetic structure at 1.8 K is consistent with the magnetic anisotropies obtained using McPhase calculations. Only Tb2 moments are ordered at 2.5 K, indicating the appearance of a partially disordered state. We also considered the origin of the two magnetic transitions.

Environmental cell for USANS/SANS studies with aggressive fluids at high pressures and temperatures

The new (Ultra) Small Angle Neutron (USANS/SANS) cell provides in-situ monitoring capability of the evolving microstructure and physical properties of a wide range of natural and artificial materials. This modular, portable compact environmental cell is designed for thermal, mechanical and chemical loading measurements compatible with all neutron and X-ray-based research facilities worldwide that is fine-tuned to a specific beamline. A seamless integration of time-lapse structural information, on scales ranging from the sub-nano to the micrometre has been demonstrated in a series of USANS/SANS experiments performed on rock samples subjected to hydrostatic and uniaxial load, reactive fluid flow and elevated temperatures. The modular design of the cell allows optimisation for specific applications, ranging from cryogenic to temperatures over 500 °C, with plans for further extensions of this range in the future. Simultaneously to thermal measurements, uniaxial mechanical stress up to 1000 bar, and sample surrounding fluid/gas pressure of up to 1000 bar in constant pressure or constant flow rate mode can be applied independently to the sample, while scattering data is collected. Due to the modular design, components such as windows, seals and pistons can be interchanged optimising the cell for use with chemically aggressive (including ultra-supercritical) fluids. This development supports research initiatives in geology, energy and minerals, resource engineering, civil engineering, material sciences, biotechnology, and medical sciences. The cell is also extendable for use in neutron diffraction and tomographic experiments.

Morphology and kinetics of nanoheterogeneities in Fe81Ga19–Tb alloy: A small-angle neutron scattering study

The formation of nanoprecipitates in the Fe81Ga19 alloy doped with Tb (∼0.1 at. %) was studied by small-angle neutron scattering (SANS). Measurements at room temperature for several samples pre-aged at a fixed temperature in the range of (300–700)°C revealed a dilute system of precipitates with a characteristic size at nanoscale (<1000 Å) growing with an increase in ageing temperature. In situ measurements during isothermal ageing at 300 °C for 3 h revealed fast (order of 10 min) formation of precipitates. SANS analysis is consistent with the results of neutron diffraction experiments, which suggest the microstructure of this alloy as a matrix of disordered atomic structure (A2 phase) with embedded precipitates of the structurally and magnetically ordered D03 phase.

High Conductivity and Diffusion Mechanism of Oxide Ions in Triple Fluorite-Like Layers of Oxyhalides.

Oxide ion conductors are attractive materials because of their wide range of applications, such as solid oxide fuel cells. Oxide ion conduction in oxyhalides (compounds containing both oxide ions and halide ions) is rare. In the present work, we found that Sillén oxychlorides, Bi2-xTexLuO4+x/2Cl (x = 0, 0.1, and 0.2), show high oxide ion conductivity. The bulk conductivity of Bi1.9Te0.1LuO4.05Cl reaches 10-2 S cm-1 at 431 °C, which is much lower than 644 °C of yttria-stabilized zirconia (YSZ) and 534 °C of La0.8Sr0.2Ga0.83Mg0.17O2.815 (LSGM). Thanks to the low activation energy, Bi1.9Te0.1LuO4.05Cl exhibits a high bulk conductivity of 1.5 × 10-3 S cm-1 even at a low temperature of 310 °C, which is 204 times higher than that of YSZ. The low activation energy is attributed to the interstitialcy oxide ion diffusion in the triple fluorite-like layer, as evidenced by neutron diffraction experiments (Rietveld and neutron scattering length density analyses), bond valence-based energy calculations, static DFT calculations, and ab initio molecular dynamics simulations. The electrical conductivity of Bi1.9Te0.1LuO4.05Cl is almost independent of the oxygen partial pressure from 10-18 to 10-4 atm at 431 °C, indicating the electrolyte domain. Bi1.9Te0.1LuO4.05Cl also exhibits high chemical stability under a CO2 flow and ambient air at 400 °C. The oxide ion conduction due to the two-dimensional interstitialcy diffusion is considered to be common in Sillén oxyhalides with triple fluorite-like layers, such as Bi1.9Te0.1RO4.05Cl (R = La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu) and Bi6-2xTe2xO8+xBr2 (x = 0.1, 0.5). The present study opens a new field of materials chemistry: oxide ion-conducting Sillén oxyhalides with triple fluorite-like layers.

The rotamer of the second-sphere histidine in AA9 lytic polysaccharide monooxygenase is pH dependent

Lytic polysaccharide monooxygenases (LPMOs) catalyze a reaction that is crucial for the biological decomposition of various biopolymers and for the industrial conversion of plant biomass. Despite the importance of LPMOs, the exact molecular-level nature of the reaction mechanism is still debated today. Here, we investigated the pH-dependent conformation of a second-sphere histidine (His) that we call the stacking histidine, which is conserved in fungal AA9 LPMOs and is speculated to assist catalysis in several of the LPMO reaction pathways.Using constant-pH and accelerated molecular dynamics simulations, we monitored the dynamics of the stacking His in different protonation states for both the resting Cu(II) and active Cu(I) forms of two fungal LPMOs. Consistent with experimental crystallographic and neutron diffraction data, our calculations suggest that the side chain of the protonated and positively charged form is rotated out of the active site toward the solvent. Importantly, only one of the possible neutral states of histidine (HIE state) is observed in the stacking orientation at neutral pH or when bound to cellulose. Our data predict that, in solution, the stacking His may act as a stabilizer (via hydrogen bonding) of the Cu(II)-superoxo complex after the LPMO-Cu(I) has reacted with O2 in solution, which, in fine, leads to H2O2 formation. Also, our data indicate that the HIE-stacking His is a poor acid/base catalyst when bound to the substrate and, in agreement with the literature, may play an important stabilizing role (via hydrogen bonding) during the peroxygenase catalysis.Our study reveals the pH titration midpoint values of the pH-dependent orientation of the stacking His should be considered when modeling and interpreting LPMO reactions, whether it be for classical LPMO kinetics or in industry-oriented enzymatic cocktails, and for understanding LPMO behavior in slightly acidic natural processes such as fungal wood decay.

Copper effects on the microstructures and deformation mechanisms of CoCrFeNi high entropy alloys

In situ neutron diffraction experiments have been performed to investigate the deformation mechanisms on CoCrFeNi high entropy alloys (HEAs) with various amounts of doped Cu. Lattice strain evolution and diffraction peak analysis were used to derive the stacking fault probability, stacking fault energy, and dislocation densities. Such diffraction analyses indirectly uncovered that a lower degree of Cu doping retained the twinning behavior in undoped CoCrFeNi HEAs, while increasing the Cu content increased the Cu clusterings which suppressed twinning and exhibited prominent dislocation strengthening. These results agree with direct observations by transmission electron microscopy.

Hydrogenation of silicon-bearing hexagonal close-packed iron and its implications for density deficits in the inner core

To investigate silicon effects on the hydrogen-induced volume expansion of iron, neutron diffraction and X-ray diffraction experiments were conducted to examine hcp-Fe0.95Si0.05 under high pressures and high temperatures. Neutron diffraction experiments were performed on the deuterated hcp-Fe0.95Si0.05 at 13.5 GPa and 900 K, and at 12.1 GPa and 300 K. The hydrogen occupancy was determined from the obtained profiles using Rietveld analysis. By combining the P–V–T equation of state of hcp-Fe0.95Si0.05, the present results indicate that the hydrogen-induced volume expansion of hcp-Fe0.95Si0.05 is 10% greater than that of pure hcp iron. Using the obtained values, we estimated the hydrogen content that would reproduce the density deficit in the inner core, which was 50% less than that without the effect of silicon. Possible hydrogen content, x, in the inner core and the outer core was calculated to be 0.07 and 0.12–0.15, respectively when reproducing the density deficit of the inner core with hcp-Fe0.95Si0.05Hx.

Residual Stress Relaxation in the Laser Welded Structure after Low-Cycle Fatigue and Fatigue Life: Numerical Analysis and Neutron Diffraction Experiment

The residual stress relaxation behaviour in low-cycle fatigue brings uncertainty to accurately predict fatigue life. Therefore, establishing the residual stress relaxation model for the welded structure is critical. In this paper, the residual stress is simulated through Abaqus finite element software (6.14). The residual stress relaxation model related to the magnitude of cyclic loading and the number of cycles is proposed. Furthermore, the residual stress relaxation model is applied to predict low-cycle fatigue life. Finally, the simulation results are validated by experimental data obtained using the reliable neutron diffraction method, and a good agreement is observed.

Effect of Cr/Mn Addition in TiVNb on Hydrogen Sorption Properties: Thermodynamics and Phase Transition Study

High-entropy alloys (HEAs) are a promising class of materials that can grant remarkable functional performances for a large range of applications due to their highly tunable composition. Among these applications, recently, bcc HEAs capable of forming fcc hydrides have been proposed as high-capacity hydrogen storage materials with improved thermodynamics compared to classical metal hydrides. In this context, a single-phase bcc (TiVNb)0.90Cr0.05Mn0.05 HEA was prepared by arc melting to evaluate the effect of combined Cr/Mn addition in the ternary TiVNb. A thermodynamic destabilization of the fcc hydride phase was found in the HEA compared to the initial TiVNb. In situ neutron and synchrotron X-ray diffraction experiments put forward a fcc → bcc phase transition of the metallic subnetwork in the temperature range of 260–350 °C, whereas the H/D subnetwork underwent an order → disorder transition at 180 °C. The absorption/desorption cycling demonstrated very fast absorption kinetics at room temperature in less than 1 min with a remarkable total capacity (2.8 wt.%) without phase segregation. Therefore, the design strategy consisting of small additions of non-hydride-forming elements into refractory HEAs allows for materials with promising properties for solid-state hydrogen storage to be obtained.

Principal Preferred Orientation Evaluation of Steel Materials Using Time-of-Flight Neutron Diffraction

Comprehensive information on in situ microstructural and crystallographic changes during the preparation/manufacturing processes of various materials is highly necessary to precisely control the microstructural morphology and the preferred orientation (or texture) characteristics for achieving an excellent strength–ductility–toughness balance in advanced engineering materials. In this study, in situ isothermal annealing experiments with cold-rolled 17Ni-0.2C (mass%) martensitic steel sheets were carried out by using the TAKUMI and ENGIN-X time-of-flight neutron diffractometers. The inverse pole figures based on full-profile refinement were extracted to roughly evaluate the preferred orientation features along three principal sample directions of the investigated steel sheets, using the General Structure Analysis System (GSAS) software with built-in generalized spherical harmonic functions. The consistent rolling direction (RD) inverse pole figures from TAKUMI and ENGIN-X confirmed that the time-of-flight neutron diffraction has high repeatability and statistical reliability, revealing that the principal preferred orientation evaluation of steel materials can be realized through 90° TD ➜ ND (transverse direction ➜ normal direction) rotation of the investigated specimen on the sample stage during two neutron diffraction experiments. Moreover, these RD, TD, and ND inverse pole figures before and after the in situ experiments were compared with the corresponding inverse pole figures recalculated from the MUSASI-L complete pole figure measurement and the HIPPO in situ microstructure evaluation, respectively. The similar orientation distribution characteristics suggested that the principal preferred orientation evaluation method can be applied to the in situ microstructural evolution of bulk orthorhombic materials and spatially resolved principal preferred orientation mappings of large engineering structure parts.

Understanding the role of aliovalent cation substitution on the li-ion diffusion mechanism in Li6+xP1-xSixS5Br argyrodites.

Due to their high ionic conductivity, lithium-ion conducting argyrodites show promise as solid electrolytes for solid-state batteries. Aliovalent substitution is an effective technique to enhance the transport properties of Li6PS5Br, where aliovalent Si substitution triples ionic conductivity. However, the origin of this experimentally observed increase is not fully understood. Our density functional theory (DFT) study reveals that Si4+ substitution increases Li diffusion by activating Li occupancy in the T4 sites. Redistribution of Li-ions within the lattice results in a more uniform distribution of Li around the T4 and neighboring T5 sites, flattening the energy landscape for diffusion. Since the T4 site is positioned in the intercage jump pathway, an increase in the intercage jump rate is found, which is directly related to the macroscopic diffusion and bulk conductivity. Analysis of neutron diffraction experiments confirms partial T4 site occupancy, in agreement with the computational findings. Understanding the aliovalent substitution effect on interstitials is crucial for improving solid electrolyte ionic conductivity and advancing solid-state battery performance.

ThCr2Si2C: An Antiferromagnetic Metal with a Cr2C Square Lattice.

A quaternary compound, ThCr2Si2C, was synthesized by using the arc-melting technique. The compound adopts a tetragonal CeCr2Si2C-type crystal structure. The electronic resistivity and specific heat data exhibit metallic behavior, while the magnetic susceptibility displays a pronounced broad peak at around 370 K, indicating the antiferromagnetic phase transition. The first-principles calculations suggest A-type antiferromagnetic ordering of the Cr sublattice, which is confirmed by neutron diffraction experiments. By comparing the crystal structure of ThCr2Si2C with the isostructural Cr-based compounds, the magnetic state of Cr 3d orbital is discussed in terms of the band-filling effects and indirect spin exchange interaction.

Synthesis, Structural and Electrochemical Investigation of Disordered Rock Salt Compounds Based on Ni and Ti

Li-ion batteries achieved in the last 3 decades extremely high energy densities, making them the energy storage devices of choice for the electrification of our society. Despite this improvement, their energy density is still low as compared to gasoline, motivating further research towards materials with better performances. State of the art positive electrodes are nowadays layered materials with a ratio Li:M of 1:1, with M being one or multiple transition metals. Disordered rock salt (DRX) materials without a layered structure were thought to be electrochemically inactive. With the development of the percolation theory, 1(Urban, Lee, and Ceder) it was demonstrated that lithium-rich materials (Li:M>1) with a cation disordered rock-salt structure (DRX) can achieve high reversible specific capacities. The general formula of these lithium-rich compounds can be written Li1+y(MM′)1−yO2 where the Li content ranges usually from 1.05 to 1.33, essential to promote Li percolation pathways. With M is indicated a redox active specie (Mn, Ni, Fe, Cr, V) and M’ is typically a d0 element, which is redox inactive during charge and discharge and therefore stabilizes the disordered structure and acting as charge compensator.2 (Chen, Ahn, and Chen)In this work a class of Li-rich compounds with the chemical composition Li2yNiyTi2-3yO2 has been investigated (y = 0.50, 0.55, 0.60, 0.67). These samples were prepared via solid-state reaction at three different temperatures (700 °C, 800 °C, 900 °C). X-ray diffraction has been used to determine the crystal structure of the samples, revealing a predominant rock salt-type phase. However, by decreasing the synthesis temperature and increasing the Li content, phase separation occurs into a rock salt-type and a Li2TiO3 phase. The synthesis has been also verified by DFT and by in situ X-ray diffraction. Neutron diffraction experiment have been carried out to fully understand the cationic distribution in the samples. Finally, the electrochemical performances of the samples have been investigated in Li half cells, revealing a strong voltage hysteresis between charge and discharge.3 (Li et al.) Bibliography Urban, Alexander, Jinhyuk Lee, and Gerbrand Ceder. “The Configurational Space of Rocksalt-Type Oxides for High-Capacity Lithium Battery Electrodes.” Advanced Energy Materials 4, no. 13 (September 2014): 1400478. https://doi.org/10.1002/aenm.201400478.Chen, Dongchang, Juhyeon Ahn, and Guoying Chen. “An Overview of Cation-Disordered Lithium-Excess Rocksalt Cathodes.” ACS Energy Letters, March 17, 2021, 1358–76. https://doi.org/10.1021/acsenergylett.1c00203.Li, Biao, Khagesh Kumar, Indrani Roy, Anatolii V. Morozov, Olga V. Emelyanova, Leiting Zhang, Tuncay Koç, et al. “Capturing Dynamic Ligand-to-Metal Charge Transfer with a Long-Lived Cationic Intermediate for Anionic Redox.” Nature Materials 21, no. 10 (October 2022): 1165–74. https://doi.org/10.1038/s41563-022-01278-2

Effect of dislocation slip and deformation twinning on the high-pressure phase transformation in Zirconium

Zirconium transforms from the α→ω phase under high hydrostatic pressures. The critical transformation pressure is expected to be affected by internal stresses associated with defects. This study focuses on the effects of dislocations and twins and their associated stress fields on the transformation. Samples are pre-loaded to seed dislocations or twins. In-situ high-hydrostatic-pressure X-ray synchrotron experiments are performed revealing that microstructures with pre-existing prismatic 〈a〉 dislocations and {101¯2} twins promote the transformation more effectively than pyramidal 〈c + a〉 dislocations or {112¯2} twins. Post-mortem electron backscatter diffraction further shows that pre-seeded defects stabilize the ω-phase at ambient conditions. In-situ stress-hold neutron diffraction experiments are also performed combining both hydrostatic and deviatoric stresses capturing the role of deviatoric stresses on phase transformation kinetics. These results support the findings of recent atomistic simulations indicating flow of prismatic 〈a〉 dislocations at an α-ω interface promotes the growth of the ω domain.

Simulating Crystal Structure, Acidity, Proton Distribution, and IR Spectra of Acid Zeolite HSAPO-34: A High Accuracy Study.

It is a challenge to characterize the acid properties of microporous materials in either experiments or theory. This study presents the crystal structure, acid site, acid strength, proton siting, and IR spectra of HSAPO-34 from the SCAN + rVV10 method. The results indicate: the crystal structures of various acid sites of HSAPO-34 deviate from the space group of R3¯; the acid strength inferred from the DPE value likely decreases with the proton binding sites at O(2), O(4), O(1),and O(3), contrary to the stability order in view of the internal energy; the calculated ensemble-averaged DPE is about 1525 kJ/mol at 673.15 K; and the proton siting and the proton distribution are distinctly influenced by the temperature: at low temperatures, the proton is predominantly located at O(3), while it prefers O(2) at high temperatures, and the proton at O(4) assumedly has the least distribution at 273.15-773.15 K. In line with the neutron diffraction experiment, a correction factor of 0.979 is needed to correct for the calculated hydroxyl stretching vibration (ν(O-H)) of HSAPO-34. It seems that the SCAN meta-GGA method, compensating for some drawbacks of the GGA method, could provide satisfying results regarding the acid properties of HSAPO-34.

Effects of Pre-Strain and Tempering on Mechanical Properties in High-Strength Martensitic Steels

Effects of pre-strain and tempering on mechanical properties in high-strength martensitic steels were investigated. In this study, strain tempering (ST) and quenching and tempering (QT) martensitic steels were prepared, and their mechanical properties were studied. In the tensile tests at the deformation temperatures between 296 and 573 K, the ST sample increased both of tensile strength (TS) and uniform elongation (U.El) from 473 to 523 K whereas the QT sample increased U.El with little change of TS. From the in situ neutron diffraction experiments, stress partitioning to the bcc phase increased with an increase in the deformation temperature from 296 to 523 K. The difference of phase stress between the bcc and cementite phases decreased with increasing the temperature because of a decrease in the cementite strength. In the ST sample, Pre-straining of 0.5% increased YS at 296 K with slight work hardening. The initial value of dislocation density (ρ) decreased at 523 K but ρ increased significantly after yielding, leading to better combination of TS and U.El. The combinations of pre-strain, tempering, and deformation temperatures have changed ρ before deformation and the increase of ρ after yielding of the martensitic steels.

Lipid bilayer properties potentially contributed to the evolutionary disappearance of betaine lipids in seed plants

BackgroundMany organisms rely on mineral nutrients taken directly from the soil or aquatic environment, and therefore, developed mechanisms to cope with the limitation of a given essential nutrient. For example, photosynthetic cells have well-defined responses to phosphate limitation, including the replacement of cellular membrane phospholipids with non-phosphorous lipids. Under phosphate starvation, phospholipids in extraplastidial membranes are replaced by betaine lipids in microalgae. In higher plants, the synthesis of betaine lipid is lost, driving plants to other strategies to cope with phosphate starvation where they replace their phospholipids by glycolipids.ResultsThe aim of this work was to evaluate to what extent betaine lipids and PC lipids share physicochemical properties and could substitute for each other. By neutron diffraction experiments and dynamic molecular simulation of two synthetic lipids, the dipalmitoylphosphatidylcholine (DPPC) and the dipalmitoyl-diacylglyceryl-N,N,N-trimethylhomoserine (DP-DGTS), we found that DP-DGTS bilayers are thicker than DPPC bilayers and therefore are more rigid. Furthermore, DP-DGTS bilayers are more repulsive, especially at long range, maybe due to unexpected unscreened electrostatic contribution. Finally, DP-DGTS bilayers could coexist in the gel and fluid phases.ConclusionThe different properties and hydration responses of PC and DGTS provide an explanation for the diversity of betaine lipids observed in marine organisms and for their disappearance in seed plants.

Development of 0.5 mm gauge size radial collimators for high-pressure neutron diffraction experiments at PLANET in J-PARC

Radial collimators with a 0.5 mm gauge size (GS) were specially designed for high-pressure neutron diffraction experiments. The performance and efficacy of these collimators, along with the 1.5 mm and 3.0 mm GS radial collimators, were investigated. The radial collimators with nominal GS of 0.75 mm, 1.5 mm, and 3.0 mm effectively exhibited GS of 0.50 mm, 1.07 mm, and 2.78 mm, respectively. The transmissions of all three radial collimators were deemed equivalent. The assessment using a Paris–Edinburgh (PE) press equipped with double-toroidal anvils and a diamond anvil cell (DAC) tailored for neutron diffraction revealed that the scattering intensity from the anvils was considerably minimized using the radial collimators and the sample-to-anvil signal ratio, as defined by the Bragg peak intensity ratio (IMgO220/IDiamond220), reached values of 0.5 and 2.0 for the PE press and DAC, respectively, when using the 0.5 mm GS radial collimators. These results indicate that the 0.5 mm GS radial collimators have been fabricated as intended and exhibit efficacy for the high-pressure-neutron diffraction experiments, specifically those exceeding 30 GPa, which cannot be reached with a PE press equipped with the standard double-toroidal anvils of a 1.5 mm cup diameter. Among those ever manufactured for neutron scattering experiments, the radial collimators display the smallest GS.