A six-axis robotic sample changer for high-throughput neutron powder diffraction and texture measurements

Abstract

State‐of‐the‐art neutron time‐of‐flight diffractometers at modern neutron sources allow sample throughput at rates of much less than one hour per sample. Automated sample changes with a high degree of reliability and flexibility are essential to assure safe operation and efficient use of available neutron flux. At the High‐Pressure Preferred Orientation (HIPPO) diffractometer, a previous sample changer measured over 2300 texture and 400 powder samples at ambient conditions to study the properties of crystalline materials at the Lujan neutron scattering facility at the Los Alamos Neutron Science Center. Experience gained during operation of the sample changer for over a decade showed room for improvement and led to a new design using current industrial robot technology. Here, the new HIPPO versatile six‐axis robotic sample changer for neutron powder diffraction experiments including texture measurements is presented.

Neutron Diffraction Measurements and Micromechanical Modelling of Temperature‐Dependent Variations in TATB Lattice Parameters

“…Neutron pulsese merging from ah igh flux/ medium resolution water moderator at 20 Hz are collimated to a1 0mmd iameterb eam spot and enter as ample chambero fc a. 2m 3 .T he sample is held in the sample environment in this chamber, in these experiments, either ar obotic sample changer [ 30] for texture measurements or aJ anis top-loading cryostat for low temperature experiments.D iffracted neutronsa re detectedw ith 1200 3 He de- tector tubes mounted on 53 detector panels, which are arranged on five rings around the incident beam with nominal diffraction angleso f1 448,1 208,9 0 8,6 0 8,a nd 408.F or texture measurements, the data of each detector panel was integrated into 45 histograms (the 16 backscattering panels are integrated into 8h istograms for improved statistics), while for the powder diffraction data collected duringt emperature changes the data was integrated into five histograms, one for each detector ring. The latter improves counting statistics and smears out the effects of weak to moderate preferred orientation due to the vast detector coverage of HIPPO, allowing data analysis that assumes random crystal orientation.…”

Improved sample manipulation at the STRESS-SPEC neutron diffractometer using an industrial 6-axis robot for texture and strain analyses

“…This include a system developed by Thyssen Company [11] where a standard X-ray diffractometer with a conventional sample table was equipped with a robot based sample changer to facilitate automated texture analysis of sample series. In a similar vein a robot system is implemented purely as a sample changer in combination with conventional sample tables at the neutron facility ANSTO at the powder diffractometer Echidna [12] and recently at the instrument Hippo at the LANSCE facility [13]. Hessert et al [14] developed a Xray diffraction stress scanner for large samples based on a concept of two cooperating 6-axis robots that position the X-ray tube and the detector in diffraction geometry relative to the component surface -an innovative use of robots which has been recently implemented also in commercial strain diffractometers.…”

Neutron Optics Upgrades to the Residual Stress Diffractometer, KOWARI

“…In 2011 it was decided that a 6 axis robot, capable of texture analysis would be purchased. At that time few if any facilities had this capability, we are currently aware of 2 facilities that can now do this, STRESS-SPEC at FRM II in Munich [4] and at the LANCSE facility in Los Alamos [5]. An Epson C3 6 axis robot was selected.…”