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Monitoring fluctuations at a synchrotron beamline using matched ion chambers: 1. modelling, data collection, and deduction of simple measures of association
Author(s) -
Chantler C. T.,
Tran C. Q.,
Paterson D.,
Barnea Z.,
Cookson D. J.
Publication year - 2000
Publication title -
x‐ray spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.447
H-Index - 45
eISSN - 1097-4539
pISSN - 0049-8246
DOI - 10.1002/1097-4539(200011/12)29:6<449::aid-xrs452>3.0.co;2-r
Subject(s) - beamline , brightness , detector , optics , beam (structure) , factory (object oriented programming) , physics , statistics , computer science , mathematics , programming language
Abstract The flux, brightness and temporal characteristics of an x‐ray source often define its utility for a specific experiment. However, there are numerous contributions to the statistics of a beam as observed by a particular detector and associated electronics. The significance of these fluctuations is often neglected, with a consequent loss of precision or accuracy of up to two orders of magnitude. An understanding of the detected statistics for a given arrangement (and the means for optimizing this) can make the difference between a successful experiment and a much more limited investigation. We explain the method for measuring a wide variety of important statistical contributions to high accuracy, and draw attention to the statistical consequences of optimized monitoring of upstream signals. We discuss the use of two matched ion chambers on a monochromatized bending magnet beam at the Photon Factory, Tsukuba, Japan. This is an illustration of a general principle, also applicable to conventional fixed x‐ray sources, for investigating simple measures of association. It allows the quantification of uncertainties of spectrometric measurements, and also allows these to be minimized. Copyright © 2000 John Wiley & Sons, Ltd.