Optimizing geophysical muon radiography using information theory

Abstract

The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. S U M M A R YCosmic ray muons are highly penetrating, with some reaching several kilometres into solid rock. Consequently, muon detectors have been used to probe the interiors of large geological structures, by observing how the muon flux varies with direction of arrival. There is an increasing need to discriminate between materials differing only slightly in bulk density. A particularly demanding application is in monitoring underground reservoirs used for CO 2 capture and storage, where bulk density changes of approximately 1 per cent are anticipated. Muon arrival is a random process, and it is the underlying expectation values, not the actual muon counts, which provide information on the physical parameters of the system. It is therefore necessary to distinguish between differences in muon counts due to real geological features, and those arising from random error. This is crucial in the low-contrast case, where the method can reach the information theoretic limit of what a data source can reveal, even in principle. To this end, methods to analyse information availability in low-contrast muon radiography have been developed, as have means to optimally interpret the available data, both for radiography and for tomography. This includes a method for calculating expectation values of muon flux for a given geological model directly, complementing existing Monte Carlo techniques. A case study, using a model of carbon capture is presented. It is shown that the new data analysis techniques have the potential to approximately double the effective sensitivity of the detectors.

Desarrollo de Técnicas de Muongrafía para Estudios Densitométricos de Objetos de Importancia Estratégica

“…Actualmente estamos trabajando en los modelos computacionales, ademas exploraremos las posibilidades del análisis de datos offline como proponen por ejemplo (Benton et al, 2020), (Vanini et al, 2019) y (Vesga-Ramírez et al, 2020). Hablaremos aquí de las mediciones y avance en el área experimental.…”

Study of Spatial Resolution of Muon Hodoscopes for Muography Applications in Geophysics

“…To obtain a muography image, is required to know a priori the properties of the object of study,for example in the case of a volcanic dome it is required to know its morphology and composition, with this information to build a model of the object of study. then make the acquisition of directional flux of muons with the instrument, Then determine the trajectories of the muons, estimate the attenuation of the flux in terms of opacity and finally make a geophysical inversion between the model and the data obtained, like [24,25,26] to obtain the average density for each pixel as a function of the number of muons detected. This work focuses on studying the improvement of the spatial resolution of this type of panels by performing a double detection for each scintillator bar, to determine the position of the bar where muons crossed, signal strength is measured at each end of the scintillator fiber.…”