Novel data analysis method for obtaining better performance from a complex 3D-printed collimator

• DOI: 10.1016/j.nima.2021.165646
• Publication Date: 2021-07-21T17:58:02Z
• Authors: Fahima F. Islam; Bianca Haberl; Jiao Y.Y. Lin; David C. Anderson; Jamie J. Molaison; Garrett E. Granroth
• Keywords: Collimator; Sample (material); SIGNAL (programming language)

Abstract Additively manufactured scattered beam collimators are increasingly being employed to boost the sample to cell peak signal ratio in high pressure neutron diffraction studies because of manufacturing versatility and performance improvements. We study how the measured diffraction pattern is affected by the presence of a collimator downstream of the sample, and develop a novel protocol that provides more effective background rejection. This protocol takes into account critical performance-determinants that were identified in this study, namely: (i) effectively identifying the collimator pattern on the detector; (ii) understanding the dependence of this pattern on sample and cell composition; and (iii) accurately identifying and differentiating the different regions of the pattern on the detector based on the dependency of the cell or sample and finally (iv) resolving the intensities at regions of the detector where neutrons scattered from the sample are preferentially represented, in order to boost the sample to cell peak signal ratio. Application of this novel analysis protocol is shown to increase the collimator performance over the traditional method.