Enhanced Semi-Empirical Modeling of Neutron-Gamma Density Logs Incorporating Pair Production Effects: Experimental Benchmarking for Improved Accuracy

Enhanced Semi-Empirical Modeling of Neutron-Gamma Density Logs Incorporating Pair Production Effects: Experimental Benchmarking for Improved Accuracy | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Enhanced Semi-Empirical Modeling of Neutron-Gamma Density Logs Incorporating Pair Production Effects: Experimental Benchmarking for Improved Accuracy Abolfazl Rafizade, Seyed Abolfazl Hosseini This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6886487/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 02 May, 2026 Read the published version in Scientific Reports → Version 1 posted 10 You are reading this latest preprint version Abstract This study introduces an improved model for neutron-gamma density (NGD) measurements, specifically designed to reduce the impact of pair production on density estimations. Using the MCNPX simulation software, the model simulates the interaction of the NGD tool with geological formations, focusing on the energy distribution of neutrons and gamma rays, and the effect of mudcake thickness on gamma flux ratios. The study investigates how varying hydrogen weight fractions, particularly those below 10%, influence gamma and neutron flux. The new model effectively mitigates errors caused by pair production, offering more accurate density estimations, especially for formations with low hydrogen content. Experimental benchmarking with a Cf-252 source was conducted to validate the simulation results, providing a comparison with real-world data. While the model demonstrates improved performance for materials with hydrogen content less than 10%, further refinements may be needed for high hydrogen fraction scenarios. Physical sciences/Physics/Applied physics Physical sciences/Physics/Nuclear physics Earth and environmental sciences/Solid earth sciences Physical sciences/Energy science and technology Neutron-Gamma Density (NGD) Pair Production Neutron Collimator Gamma Flux Model Validation Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 02 May, 2026 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 30 Jul, 2025 Reviews received at journal 27 Jul, 2025 Reviews received at journal 23 Jul, 2025 Reviewers agreed at journal 23 Jul, 2025 Reviewers agreed at journal 23 Jul, 2025 Reviewers invited by journal 23 Jul, 2025 Editor assigned by journal 23 Jul, 2025 Editor invited by journal 27 Jun, 2025 Submission checks completed at journal 27 Jun, 2025 First submitted to journal 13 Jun, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6886487","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":490277674,"identity":"1acce0aa-4c1e-4226-8b57-1d105a6e6685","order_by":0,"name":"Abolfazl Rafizade","email":"data:image/png;base64,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","orcid":"","institution":"Sharif University of Technology","correspondingAuthor":true,"prefix":"","firstName":"Abolfazl","middleName":"","lastName":"Rafizade","suffix":""},{"id":490277675,"identity":"44bab505-fc41-4fab-8224-d36db6646ff8","order_by":1,"name":"Seyed Abolfazl Hosseini","email":"","orcid":"","institution":"Sharif University of Technology","correspondingAuthor":false,"prefix":"","firstName":"Seyed","middleName":"Abolfazl","lastName":"Hosseini","suffix":""}],"badges":[],"createdAt":"2025-06-13 08:53:18","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6886487/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6886487/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-026-40920-w","type":"published","date":"2026-05-02T15:57:29+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":108809180,"identity":"099d3240-52f5-4ed2-8ef3-81e90ae10b4e","added_by":"auto","created_at":"2026-05-08 15:50:39","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1510881,"visible":true,"origin":"","legend":"","description":"","filename":"finalpair094615.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6886487/v1_covered_9719af88-31fb-401f-9a0e-68dcd2b089ae.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Enhanced Semi-Empirical Modeling of Neutron-Gamma Density Logs Incorporating Pair Production Effects: Experimental Benchmarking for Improved Accuracy","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Neutron-Gamma Density (NGD), Pair Production, Neutron Collimator, Gamma Flux, Model Validation","lastPublishedDoi":"10.21203/rs.3.rs-6886487/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6886487/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study introduces an improved model for neutron-gamma density (NGD) measurements, specifically designed to reduce the impact of pair production on density estimations. 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