Simulation of non X-ray background for the DIffuse X-ray Explorer (DIXE) mission

Simulation of non X-ray background for the DIffuse X-ray Explorer (DIXE) mission | 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 Research Article Simulation of non X-ray background for the DIffuse X-ray Explorer (DIXE) mission Ruixuan Tian, Junjie Mao, Jiejia Liu, Hai Jin, Wei Cui This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8576846/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 25 Apr, 2026 Read the published version in Experimental Astronomy → Version 1 posted 7 You are reading this latest preprint version Abstract DIffuse X-ray Explorer (DIXE) is a proposed high-resolution spectroscopic survey mission onboard the China Space Station. Equipped with microcalorimeters based on the Transition-edge sensor technology, it aims to survey the hot gas in the Milky Way. The performance of DIXE depends on the understanding of non X-ray background (NXB), which can strongly affect observations of diffuse X-ray emission. In this work, we simulated the NXB of DIXE in a low-earth orbit (LEO) using Geant4. A detailed mass model of the payload was constructed, and the major sources of NXB were identified, including cosmic rays, albedo neutrons and albedo photons. These components were implemented in Geant4 with realistic angular and spectral distributions. We simulated the relevant physical processes of space radiation interacting with the instrument and calculated the resulting NXB. We also evaluated the delayed background from trapped protons in the South Atlantic Anomaly (SAA). Our simulations show that, at the geomagnetic equator and under solar minimum conditions, the NXB is typically 0.528 counts s-1cm-2, with dominant contributions from the induced particles generated by primary cosmic protons and alpha particles. The NXB increases toward higher geomagnetic latitudes, reaching a maximum of 2.11 counts s-1cm-2. The delayed background induced by the SAA decays rapidly after exiting the anomaly and becomes negligible within approximately 15 minutes. The simulated NXB is consistent with that of similar X-ray observatories in LEOs. X-ray instrumentation Non X-ray Background Geant4 Low Earth orbit DIXE Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 25 Apr, 2026 Read the published version in Experimental Astronomy → Version 1 posted Editorial decision: Revision requested 11 Feb, 2026 Reviews received at journal 11 Feb, 2026 Reviewers agreed at journal 19 Jan, 2026 Reviewers invited by journal 16 Jan, 2026 Editor assigned by journal 16 Jan, 2026 Submission checks completed at journal 15 Jan, 2026 First submitted to journal 11 Jan, 2026 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. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-8576846","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":576936493,"identity":"17ca27d0-df80-45bd-afa7-dca2e062755f","order_by":0,"name":"Ruixuan Tian","email":"","orcid":"","institution":"Tsinghua University","correspondingAuthor":false,"prefix":"","firstName":"Ruixuan","middleName":"","lastName":"Tian","suffix":""},{"id":576936494,"identity":"fd80184d-aab2-4197-b4a9-15b981daf8e7","order_by":1,"name":"Junjie Mao","email":"","orcid":"","institution":"Tsinghua University","correspondingAuthor":false,"prefix":"","firstName":"Junjie","middleName":"","lastName":"Mao","suffix":""},{"id":576936495,"identity":"4424ebea-5afe-4722-88a5-28a50c49d551","order_by":2,"name":"Jiejia Liu","email":"","orcid":"","institution":"Tsinghua University","correspondingAuthor":false,"prefix":"","firstName":"Jiejia","middleName":"","lastName":"Liu","suffix":""},{"id":576936496,"identity":"db196d84-fa50-410b-870d-307b69c747c7","order_by":3,"name":"Hai Jin","email":"","orcid":"","institution":"Tsinghua University","correspondingAuthor":false,"prefix":"","firstName":"Hai","middleName":"","lastName":"Jin","suffix":""},{"id":576936497,"identity":"3fb39d89-1be3-4c5c-8008-fbac30a025c0","order_by":4,"name":"Wei Cui","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA1klEQVRIiWNgGAWjYFACxsYHDAwSYAQEzERpaTY4QKIWBjaJAyCKaC38M5Lbqj/8sciTj+4x/MBQYZ3YwH72AF4tEjcS224cbJMoNrxzxliC4Ux6YgNPXgJeLQYSIC0NEokbZ+QYSDC2HU5skOAxIKil4MAfsBbjH4z/iNTCcIBNInG+RI6ZBGMDEVokzjxsljjbJpG4QSKtzCLhWLpxG08Ofi387ekPP1T8qUucPyN5840PNday/exn8GtBuPAAkEgAYjbi1AOBfAPRSkfBKBgFo2CkAQBy7UZ8x8uIcgAAAABJRU5ErkJggg==","orcid":"","institution":"Tsinghua University","correspondingAuthor":true,"prefix":"","firstName":"Wei","middleName":"","lastName":"Cui","suffix":""}],"badges":[],"createdAt":"2026-01-12 03:23:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8576846/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8576846/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10686-026-10053-z","type":"published","date":"2026-04-25T15:59:53+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":100648863,"identity":"13b128ce-425c-42e4-a819-f5bd5b5a53b5","added_by":"auto","created_at":"2026-01-20 05:36:01","extension":"json","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":7285,"visible":true,"origin":"","legend":"","description":"","filename":"090ef37721f24a9e82fe7ba0be56e0b3.json","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/dc34ca1f4deb7966be25620e.json"},{"id":100648860,"identity":"cdb20f42-4ef2-4eb1-a398-e3a0cbf8ba82","added_by":"auto","created_at":"2026-01-20 05:36:00","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":9674900,"visible":true,"origin":"","legend":"","description":"","filename":"DIXEbackgroundsimulation.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/a3b20f03ddcc624bc6df3670.pdf"},{"id":100648832,"identity":"1b89fd81-6293-4277-9f17-ba4cae7c75fa","added_by":"auto","created_at":"2026-01-20 05:35:46","extension":"png","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1241387,"visible":true,"origin":"","legend":"","description":"","filename":"Fig1.png","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/c7827a4c7c6386c2751472e4.png"},{"id":100648870,"identity":"8047d6f0-e13b-47ca-a2ee-d694f5f9ca42","added_by":"auto","created_at":"2026-01-20 05:36:04","extension":"png","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":4457123,"visible":true,"origin":"","legend":"","description":"","filename":"Fig10.png","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/400d4cbf1ad09e39cec6f2e6.png"},{"id":100648820,"identity":"f9cb2c3e-008e-45eb-b925-edcb7974c5e6","added_by":"auto","created_at":"2026-01-20 05:35:35","extension":"png","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":493875,"visible":true,"origin":"","legend":"","description":"","filename":"Fig11.png","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/5debc5e9f0e7436826e6539f.png"},{"id":100648850,"identity":"95fd6823-32f1-4085-a5eb-1e9b44c6e2ae","added_by":"auto","created_at":"2026-01-20 05:35:56","extension":"png","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":393986,"visible":true,"origin":"","legend":"","description":"","filename":"Fig12.png","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/bf93df68be81ac580597d86c.png"},{"id":100648828,"identity":"7f11b953-6b7a-40f1-a70e-0376b636d24d","added_by":"auto","created_at":"2026-01-20 05:35:44","extension":"png","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":994129,"visible":true,"origin":"","legend":"","description":"","filename":"Fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/e869bd9e7f675ddfdb216fc7.png"},{"id":100648830,"identity":"33d3261a-612c-4efb-81ef-4d0454e837be","added_by":"auto","created_at":"2026-01-20 05:35:44","extension":"png","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1162007,"visible":true,"origin":"","legend":"","description":"","filename":"Fig3.png","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/c4843d84848aae689b3e1ddb.png"},{"id":100648819,"identity":"1a53676a-dc26-4a06-8d56-f400479969ab","added_by":"auto","created_at":"2026-01-20 05:35:34","extension":"png","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":290658,"visible":true,"origin":"","legend":"","description":"","filename":"Fig4.png","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/d133bde8e33b41a8b2a3f6b3.png"},{"id":100648826,"identity":"be25e791-2816-46b8-a19f-d71f0e903a91","added_by":"auto","created_at":"2026-01-20 05:35:43","extension":"png","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1230353,"visible":true,"origin":"","legend":"","description":"","filename":"Fig5.png","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/c90e58a68302408da33cabe6.png"},{"id":100648824,"identity":"2c1ee57c-7b1b-44a5-b7f5-15fa04268bad","added_by":"auto","created_at":"2026-01-20 05:35:40","extension":"png","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":275064,"visible":true,"origin":"","legend":"","description":"","filename":"Fig6.png","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/0ebbb00500ce43737480b874.png"},{"id":100648831,"identity":"5a4beacf-6915-471a-bdba-acd521a2bf90","added_by":"auto","created_at":"2026-01-20 05:35:46","extension":"png","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":760061,"visible":true,"origin":"","legend":"","description":"","filename":"Fig7.png","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/62e77519a548f85b06fa4260.png"},{"id":100648834,"identity":"5fd5fb83-9890-4a72-bc16-feb0cf530ad0","added_by":"auto","created_at":"2026-01-20 05:35:50","extension":"png","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":350133,"visible":true,"origin":"","legend":"","description":"","filename":"Fig8.png","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/b6ba10d0af2d55cba1659c6a.png"},{"id":100648817,"identity":"f290e447-d0ab-445c-8063-755414e986c2","added_by":"auto","created_at":"2026-01-20 05:35:32","extension":"png","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":486394,"visible":true,"origin":"","legend":"","description":"","filename":"Fig9.png","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/8e050a6ff6926e64d1129f1b.png"},{"id":100648816,"identity":"0b5a7a1d-e4df-4ca3-81cc-8bfd07b5ecab","added_by":"auto","created_at":"2026-01-20 05:35:26","extension":"pdf","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":79395,"visible":true,"origin":"","legend":"","description":"","filename":"coverletter.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/a17dcb29dd5218bf88acf62e.pdf"},{"id":100648858,"identity":"8f1cc989-358b-4264-98f5-04f25d43170b","added_by":"auto","created_at":"2026-01-20 05:35:59","extension":"bst","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":35515,"visible":true,"origin":"","legend":"","description":"","filename":"snbasic.bst","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/787f19eefc0323cd40ee1b3e.bst"},{"id":100648841,"identity":"01fed4ba-c6b0-4f56-9c37-009cac7c7950","added_by":"auto","created_at":"2026-01-20 05:35:54","extension":"cls","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":55857,"visible":true,"origin":"","legend":"","description":"","filename":"snjnl.cls","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/793ce60f1a0d9840aeb6fb42.cls"},{"id":100648859,"identity":"f7bf6ba6-afbd-41e3-bceb-74ff1dc4a21c","added_by":"auto","created_at":"2026-01-20 05:36:00","extension":"bst","order_by":17,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":64023,"visible":true,"origin":"","legend":"","description":"","filename":"snmathphysay.bst","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/bc241b194898fc8cbc54d53e.bst"},{"id":100648818,"identity":"723d5c0a-2688-4f12-9f43-a3083ce2eada","added_by":"auto","created_at":"2026-01-20 05:35:32","extension":"bst","order_by":18,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":64166,"visible":true,"origin":"","legend":"","description":"","filename":"snmathphysnum.bst","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/373ab913feac29a0758a9db7.bst"},{"id":100648825,"identity":"a0901bb7-5fdb-4212-945e-70fc2362a43d","added_by":"auto","created_at":"2026-01-20 05:35:42","extension":"png","order_by":19,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":401509,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineFig11.png","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/9a75aa05523b0ad9455c5828.png"},{"id":100648845,"identity":"18038dd6-8f94-4eed-ab5f-18ca29e35f62","added_by":"auto","created_at":"2026-01-20 05:35:55","extension":"png","order_by":20,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":243147,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineFig6.png","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/60b7e87baf73fface63db573.png"},{"id":100648872,"identity":"ceeaf218-5d0d-438e-bddf-54811e05ad75","added_by":"auto","created_at":"2026-01-20 05:36:05","extension":"xml","order_by":21,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":174801,"visible":true,"origin":"","legend":"","description":"","filename":"090ef37721f24a9e82fe7ba0be56e0b31structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1/ec945370249a810f487426f0.xml"},{"id":107928190,"identity":"b25deb5e-ed83-4817-9ad9-b117214d8d16","added_by":"auto","created_at":"2026-04-27 16:09:09","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":11088104,"visible":true,"origin":"","legend":"","description":"","filename":"DIXEbackgroundsimulation.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8576846/v1_covered_972e9424-9358-4f73-825c-7a171e70af4f.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Simulation of non X-ray background for the DIffuse X-ray Explorer (DIXE) mission","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":"experimental-astronomy","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"expa","sideBox":"Learn more about [Experimental Astronomy](http://link.springer.com/journal/10686)","snPcode":"10686","submissionUrl":"https://submission.nature.com/new-submission/10686/3","title":"Experimental Astronomy","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"X-ray instrumentation, Non X-ray Background, Geant4, Low Earth orbit, DIXE","lastPublishedDoi":"10.21203/rs.3.rs-8576846/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8576846/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"DIffuse X-ray Explorer (DIXE) is a proposed high-resolution spectroscopic survey mission onboard the China Space Station. Equipped with microcalorimeters based on the Transition-edge sensor technology, it aims to survey the hot gas in the Milky Way. The performance of DIXE depends on the understanding of non X-ray background (NXB), which can strongly affect observations of diffuse X-ray emission. In this work, we simulated the NXB of DIXE in a low-earth orbit (LEO) using Geant4. A detailed mass model of the payload was constructed, and the major sources of NXB were identified, including cosmic rays, albedo neutrons and albedo photons. These components were implemented in Geant4 with realistic angular and spectral distributions. We simulated the relevant physical processes of space radiation interacting with the instrument and calculated the resulting NXB. We also evaluated the delayed background from trapped protons in the South Atlantic Anomaly (SAA). Our simulations show that, at the geomagnetic equator and under solar minimum conditions, the NXB is typically 0.528 counts s-1cm-2, with dominant contributions from the induced particles generated by primary cosmic protons and alpha particles. The NXB increases toward higher geomagnetic latitudes, reaching a maximum of 2.11 counts s-1cm-2. The delayed background induced by the SAA decays rapidly after exiting the anomaly and becomes negligible within approximately 15 minutes. The simulated NXB is consistent with that of similar X-ray observatories in LEOs.","manuscriptTitle":"Simulation of non X-ray background for the DIffuse X-ray Explorer (DIXE) mission","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-20 05:34:26","doi":"10.21203/rs.3.rs-8576846/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-02-11T15:39:52+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-11T15:02:16+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"148155869338042567724605316577358008898","date":"2026-01-19T14:57:19+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-01-16T07:54:27+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-01-16T07:42:54+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-01-15T08:38:16+00:00","index":"","fulltext":""},{"type":"submitted","content":"Experimental Astronomy","date":"2026-01-12T03:13:33+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"experimental-astronomy","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"expa","sideBox":"Learn more about [Experimental Astronomy](http://link.springer.com/journal/10686)","snPcode":"10686","submissionUrl":"https://submission.nature.com/new-submission/10686/3","title":"Experimental Astronomy","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"3ce57bf5-7689-439c-b3e7-5e92b84836e0","owner":[],"postedDate":"January 20th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-04-27T16:05:41+00:00","versionOfRecord":{"articleIdentity":"rs-8576846","link":"https://doi.org/10.1007/s10686-026-10053-z","journal":{"identity":"experimental-astronomy","isVorOnly":false,"title":"Experimental Astronomy"},"publishedOn":"2026-04-25 15:59:53","publishedOnDateReadable":"April 25th, 2026"},"versionCreatedAt":"2026-01-20 05:34:26","video":"","vorDoi":"10.1007/s10686-026-10053-z","vorDoiUrl":"https://doi.org/10.1007/s10686-026-10053-z","workflowStages":[]},"version":"v1","identity":"rs-8576846","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8576846","identity":"rs-8576846","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}