[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-1-en-105":3,"doc-seo-565416-105":53,"doc-detail-565416-en":126},{"code":4,"msg":5,"data":6},0,"success",[7,14,19,24,29,34,39,44,49],{"id":8,"doc_module":9,"doc_module_name":10,"category_name":11,"show_sort_weight":12,"slug":13},11,1,"Template","Presentations",90,"presentations",{"id":15,"doc_module":9,"doc_module_name":10,"category_name":16,"show_sort_weight":17,"slug":18},12,"Resumes",80,"resumes",{"id":20,"doc_module":9,"doc_module_name":10,"category_name":21,"show_sort_weight":22,"slug":23},14,"Invoices",70,"invoices",{"id":25,"doc_module":9,"doc_module_name":10,"category_name":26,"show_sort_weight":27,"slug":28},15,"Posters",60,"posters",{"id":30,"doc_module":9,"doc_module_name":10,"category_name":31,"show_sort_weight":32,"slug":33},16,"Social Media",50,"social-media",{"id":35,"doc_module":9,"doc_module_name":10,"category_name":36,"show_sort_weight":37,"slug":38},17,"Forms",40,"forms",{"id":40,"doc_module":9,"doc_module_name":10,"category_name":41,"show_sort_weight":42,"slug":43},18,"Letters",30,"letters",{"id":45,"doc_module":9,"doc_module_name":10,"category_name":46,"show_sort_weight":47,"slug":48},21,"Paper Templates",5,"papers-templates",{"id":50,"doc_module":9,"doc_module_name":10,"category_name":51,"show_sort_weight":4,"slug":52},158,"General","general-158",{"code":4,"msg":54,"data":55},"ok",{"site_id":56,"language":57,"slug":58,"title":59,"keywords":60,"description":61,"schema_data":62,"social_meta":119,"head_meta":121,"extra_data":123,"updated_unix":125},105,"en","cosmic-muon-flux-at-shallow-depths-underground-abstract","Cosmic muon flux at shallow depths underground - Abstract","","Cosmic muon background is analyzed for installations at shallow underground depths to support low-background measurements in fundamental and applied experiments. A relatively simple formula is proposed for the sea-level muon spectrum, enabling calculation of vertical muon intensity and integral muon flux density as functions of overburden. Results show nearly unchanged muon angular distribution from 10 to 100 m of standard rock, and indicate that an active shielding “umbrella” should cover zenith angles θ ≈ 80° to suppress the background.",{"@graph":63,"@context":118},[64,80,101],{"@type":65,"itemListElement":66},"BreadcrumbList",[67,71,74,77],{"item":68,"name":69,"@type":70,"position":9},"https://docshare.wps.com","Home","ListItem",{"item":72,"name":10,"@type":70,"position":73},"https://docshare.wps.com/template/",2,{"item":75,"name":51,"@type":70,"position":76},"https://docshare.wps.com/template/general/",3,{"item":78,"name":59,"@type":70,"position":79},"https://docshare.wps.com/template/cosmic-muon-flux-at-shallow-depths-underground-abstract/565416/",4,{"url":78,"name":59,"@type":81,"image":82,"author":87,"headline":59,"publisher":90,"fileFormat":93,"inLanguage":57,"description":61,"dateModified":94,"datePublished":95,"encodingFormat":93,"isAccessibleForFree":96,"interactionStatistic":97},"DigitalDocument",{"url":83,"@type":84,"width":85,"height":86},"https://docshare.wps.com/thumbnails/cosmic-muon-flux-at-shallow-depths-underground-abstract/565416.png","ImageObject",442,249,{"name":88,"@type":89},"Nguyễn Văn Học","Person",{"url":68,"name":91,"@type":92},"DocShare","Organization","application/pdf","2026-10-20","2026-10-13",true,{"@type":98,"interactionType":99,"userInteractionCount":73},"InteractionCounter",{"@type":100},"ViewAction",{"@type":102,"mainEntity":103},"FAQPage",[104,110,114],{"name":105,"@type":106,"acceptedAnswer":107},"What problem does the document address for shallow-depth installations?","Question",{"text":108,"@type":109},"It examines the cosmic muon background at shallow underground depths and how to predict and suppress it for low-background experiments.","Answer",{"name":111,"@type":106,"acceptedAnswer":112},"What does the proposed sea-level muon spectrum formula enable?",{"text":113,"@type":109},"It enables calculating the dependence of vertical muon intensity and integral muon flux density on the amount of overburden.",{"name":115,"@type":106,"acceptedAnswer":116},"Why is the active shielding “umbrella” required to overlap θ ≈ 80°?",{"text":117,"@type":109},"To remove the cosmic muon background effectively for such installations based on the presented muon angular distributions.","https://schema.org",{"og:url":78,"og:type":120,"og:title":59,"og:site_name":91,"og:description":61},"article",{"robots":122,"canonical":78},"index,follow",{"doc_id":124,"site_id":56},565416,1792478668,{"code":4,"msg":5,"data":127},{"doc_id":124,"user_id":128,"nickname":88,"user_avatar":129,"doc_module":9,"category_id":50,"category_name":51,"doc_title":59,"doc_description":61,"doc_content":130,"file_id":131,"file_url":132,"file_type":133,"file_size":134,"view_count":73,"is_deleted":4,"is_public":9,"is_downloadable":9,"audit_status":9,"page_count":135,"language":136,"language_code":57,"site_id":56,"html_lang":57,"table_of_contents":137,"faqs":138,"seo_title":139,"seo_description":61,"update_tm":140,"read_time":76},1374402739827,"https://ap-avatar.wpscdn.com/avatar/14000c97e7351f1a627?x-image-process=image/resize,m_fixed,w_180,h_180&k=1787885694763230660","Cosmic muon flux at shallow depths underground.  \nL.N.Bogdanova, M. G. Gavrilov, V.N. Kornoukhov, A.S.Starostin, Institute for Theoretical and Experimental Physics, B. Cheremushkinskaya ul, 25, Moscow  \n117218, Russia  \nAbstract  \nWe consider the cosmic muon background for the installations located at shallow depths. We suggest a relatively simple formula for the sea-level muon spectrum, which allows calculate dependencies of the vertical muon intensity and integral muon flux density on overburden. Muon flux dependency on the zenith angle at overburden of 10 to 100 meters of standard rock shows that muon angular distribution practically does not change in this interval. We present muon angular distributions for three typical apparatus locations in measurements on the surface and at shallow depths. It is shown that for such installations the active shielding “umbrella” should overlap a zenith angle of θ ~ 80° to remove the cosmic muon background.  \n1. Introduction  \nIntensity of the muon component of cosmic rays (CR) at relatively small depth underground (from tens to several hundred meters of water equivalent (m w.e.)) is of practical interest for many fundamental studies and applied research based on the lowbackground measurements. These might be reactor experiments on neutrino oscillations [1- 3], searches of the neutrino magnetic moment at reactors [4,5] or with the artificial antineutrino source [6], studies associated with measurements of low activities in materials. CR background at the sea level consists of three main components:  \n• Soft (electrons and γ-quanta of electromagnetic showers);  \n• Hadronic (hadrons of nuclear showers);  \n• Hard ( µ+/- ) .  \nPartition of sea-level CR flux is shown in Table 1.  \nTable 1. Percentage of sea-level CR flux components [7] .  \n\n| Total flux | Muons | Secondary\u003Cbr>neutrons | Electrons | Protons, pions |\n| --- | --- | --- | --- | --- |\n| 3⋅10-2 cm-2s-1 | 63% | 21% | 15% | \u003C 1% |\n\nFor practically complete suppression of the soft CR component a lead layer of ~15 cm thickness is enough. The charged CR component can be registered very efficiently; hence this background can be easily removed by using anti-coincidences (AC) . Complications with suppression of the charged CR component come up when installation surface is large:  \n≥ 100 m2, when numerous counts in AC system result in a noticeable loss of useful events (experiments on neutrino oscillations) . A more serious problem is a removal of the neutron background. Secondary neutrons are generated by hadronic CR component in the atmosphere. At sea level their flux density is 5⋅10-3n⋅cm-2 ⋅s-1 and decreases exponentially with depth (λ~165÷ 200 g ⋅cm-2, depending on the medium properties) . To suppress the secondary neutron flux by a factor of 100, a shielding thickness of about ~1000 g ⋅cm-2 is required, or ~ 4 m of a standard rock (SR) 1.  \nTertiary neutrons emerge in the electromagnetic processes when high-energy muons pass through matter and in the capture of slow muons by nuclei. Since large penetrating ability is specific for muons, intensity of accompanying tertiary neutrons decreases with depth rather slowly. This makes noticeable difficulties for experimentalists, especially if neutrons are produced in the passive shielding of the detector [8] . In slow muon capture by nuclei, hundreds of microseconds can pass from the moment of muon capture to Bohr orbit till its absorption by a nucleus followed by neutron emission. Such background events are removed by AC system by working out a forbidding signal of matching duration. To make anti-coincidences effective and do not pass over useful events, it is necessary to have reliable information on the intensity and angular distribution of the muon flux (MF) in the setup location.  \nFor today there are plenty of works devoted to MF calculation. However, most of them were performed for specific experimental installations located at depths of several thousand m w. e.. Besides, these calculat","cbCailOA1ah6wfnq","https://ap.wps.com/l/cbCailOA1ah6wfnq","pdf",456492,9,"English","# Abstract\n# 1. Introduction\n## Components of cosmic-ray flux\n## Suppression of charged and neutron backgrounds\n# 2. Calculation of muon flux at small depth","[{\"question\":\"What problem does the document address for shallow-depth installations?\",\"answer\":\"It examines the cosmic muon background at shallow underground depths and how to predict and suppress it for low-background experiments.\"},{\"question\":\"What does the proposed sea-level muon spectrum formula enable?\",\"answer\":\"It enables calculating the dependence of vertical muon intensity and integral muon flux density on the amount of overburden.\"},{\"question\":\"Why is the active shielding “umbrella” required to overlap θ ≈ 80°?\",\"answer\":\"To remove the cosmic muon background effectively for such installations based on the presented muon angular distributions.\"}]","Cosmic muon flux at shallow depths underground - Abstract | PDF",1791853334]