Sample positioning in neutron diffraction experiments using a multi-material fiducial marker

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• 作者：D. Marais^a ; ^b ; ^{Deon.Marais@necsa.co.za" class="auth_mail" title="E-mail the corresponding author} ; A.M. Venter^a ; ^c ; ^{Andrew.Venter@necsa.co.za" class="auth_mail" title="E-mail the corresponding author} ; J. Markgraaff^b ; ^{Johan.Markgraaff@nwu.ac.za" class="auth_mail" title="E-mail the corresponding author} ; J. James^d ; ^{Jon.James@open.ac.uk" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Neutron diffraction ; Strain scanning ; Sample positioning ; Artificial neural network
• 刊名：Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
• 出版年：2017
• 出版时间：1 January 2017
• 年：2017
• 卷：841
• 期：Complete
• 页码：12-16
• 全文大小：1137 K

文摘

An alternative sample positioning method is reported for use in conjunction with sample positioning and experiment planning software systems deployed on some neutron diffraction strain scanners. In this approach, the spherical fiducial markers and location trackers used with optical metrology hardware are replaced with a specifically designed multi-material fiducial marker that requires one diffraction measurement. In a blind setting, the marker position can be determined within an accuracy of ±164 µm with respect to the instrument gauge volume. The scheme is based on a pre-determined relationship that links the diffracted peak intensity to the absolute positioning of the fiducial marker with respect to the instrument gauge volume. Two methods for establishing the linking relationship are presented, respectively based on fitting multi-dimensional quadratic functions and a cross-correlation artificial neural network.