{"id":14827,"date":"2026-03-05T22:24:39","date_gmt":"2026-03-05T21:24:39","guid":{"rendered":"https:\/\/lyceerudloff.com\/?p=14827"},"modified":"2026-03-10T21:55:23","modified_gmt":"2026-03-10T20:55:23","slug":"international-cosmic-days-2025","status":"publish","type":"post","link":"https:\/\/lyceerudloff.com\/index.php\/2026\/03\/05\/international-cosmic-days-2025\/","title":{"rendered":"International Cosmic Days 2025"},"content":{"rendered":"\n<h3 class=\"wp-block-heading\"><br><strong>La journ\u00e9e internationale cosmique <\/strong>est l&rsquo;occasion pour des \u00e9l\u00e8ves de diff\u00e9rents pays de contribuer \u00e0 un m\u00eame travail d&rsquo;investigation scientifique sur le th\u00e8me des particules cosmiques.<\/h3>\n\n\n\n<div style=\"height:4px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p>Pour l\u2019\u00e9dition 2025, quatre \u00e9l\u00e8ves du groupe Sciences+ du lyc\u00e9e ont mesur\u00e9 la dur\u00e9e de vie moyenne du muon dans son r\u00e9f\u00e9rentiel propre.<\/p>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:50%\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"496\" height=\"372\" src=\"https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-4.png\" alt=\"\" class=\"wp-image-14832\" srcset=\"https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-4.png 496w, https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-4-300x225.png 300w\" sizes=\"auto, (max-width: 496px) 100vw, 496px\" \/><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:50%\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"492\" height=\"370\" src=\"https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-5.png\" alt=\"\" class=\"wp-image-14833\" srcset=\"https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-5.png 492w, https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-5-300x226.png 300w\" sizes=\"auto, (max-width: 492px) 100vw, 492px\" \/><\/figure>\n<\/div>\n<\/div>\n\n\n\n<p><br>Pour cela, nous avons utilis\u00e9 un scintillateur qui fait partie de la \u00ab Roue Cosmique \u00bb, dispositif de l\u2019op\u00e9ration \u00ab Sciences \u00e0 l\u2019Ecole \u00bb.<br>Le muon est une particule \u00e9l\u00e9mentaire, \u00e9lectriquement charg\u00e9e. Il est 207 fois plus \u00ab lourd \u00bb que son \u00ab cousin \u00bb, l\u2019\u00e9lectron. Une autre diff\u00e9rence est que le muon \u00ab meurt \u00bb : sa dur\u00e9e de vie moyenne mesur\u00e9e avec une horloge embarqu\u00e9e avec le muon, est de 2.197 \u00b5s.<br>La d\u00e9sint\u00e9gration se fait selon :<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"350\" height=\"78\" src=\"https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-2.png\" alt=\"\" class=\"wp-image-14830\" srcset=\"https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-2.png 350w, https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-2-300x67.png 300w\" sizes=\"auto, (max-width: 350px) 100vw, 350px\" \/><\/figure>\n\n\n\n<p>Parmi les produits de d\u00e9sint\u00e9gration, il est \u00e0 noter la pr\u00e9sence d\u2019un \u00e9lectron.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"556\" height=\"420\" src=\"https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-6.png\" alt=\"\" class=\"wp-image-14834\" srcset=\"https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-6.png 556w, https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-6-300x227.png 300w\" sizes=\"auto, (max-width: 556px) 100vw, 556px\" \/><\/figure>\n<\/div>\n\n\n<p>On montre que, dans le r\u00e9f\u00e9rentiel propre du muon, le nombre N<sub>0 <\/sub>de muons pr\u00e9sents \u00e0 un instant t = 0 d\u00e9cro\u00eet de fa\u00e7on exponentielle selon&nbsp;:&nbsp; N=N0. exp (-t\/\u03c4), o\u00f9 \u03c4 d\u00e9signe la dur\u00e9e de vie moyenne du muon.<\/p>\n\n\n\n<p>Le document 1 illustre le principe de la mesure de la dur\u00e9e de vie en question. La majorit\u00e9 des muons passe \u00e0 travers le scintillateur et en cela il engendre seulement un signal dans le d\u00e9tecteur. Plus rarement, un muon se d\u00e9sint\u00e8gre dans le d\u00e9tecteur (\u00e9v\u00e9nement qui nous int\u00e9resse). A ce moment-l\u00e0, on enregistre deux signaux&nbsp;:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Le premier correspond \u00e0 l\u2019entr\u00e9e du muon dans le d\u00e9tecteur (signal START)<\/li>\n\n\n\n<li>Le deuxi\u00e8me correspond \u00e0 la d\u00e9tection de l\u2019\u00e9lectron provenant de la d\u00e9sint\u00e9gration du muon (signal STOP).<\/li>\n<\/ul>\n\n\n\n<p>La dur\u00e9e s\u00e9parant ces deux signaux nous fournit la dur\u00e9e de vie du muon. Pour obtenir une statistique suffisante, nous avons enregistr\u00e9 les \u00e9v\u00e9nements sur une p\u00e9riode de 19 heures.<\/p>\n\n\n\n<p>Les r\u00e9sultats sont donn\u00e9s sans le document 2. L\u2019erreur sur le nombre de muons N est de racine de N.<\/p>\n\n\n\n<p>On obtient une valeur de 2.2 \u00b5s, valeur en tr\u00e8s bon accord avec la valeur de r\u00e9f\u00e9rence rappel\u00e9e plus haut.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"908\" height=\"410\" src=\"https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-7.png\" alt=\"\" class=\"wp-image-14835\" srcset=\"https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-7.png 908w, https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-7-300x135.png 300w, https:\/\/lyceerudloff.com\/wp-content\/uploads\/2026\/03\/image-7-768x347.png 768w\" sizes=\"auto, (max-width: 908px) 100vw, 908px\" \/><\/figure>\n\n\n\n<p>La contribution des \u00e9l\u00e8ves du lyc\u00e9e Marcel Rudloff est \u00e0 retrouver avec les autres contributions des diff\u00e9rents pays dans le Booklet icd25 \u00e0 l\u2019adresse&nbsp;:<\/p>\n\n\n\n<p><a href=\"https:\/\/syncandshare.desy.de\/index.php\/s\/Wt36mw3CjHyNt3R\">https:\/\/syncandshare.desy.de\/index.php\/s\/Wt36mw3CjHyNt3R<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>La journ\u00e9e internationale cosmique est l&rsquo;occasion pour des \u00e9l\u00e8ves de diff\u00e9rents pays de contribuer \u00e0 un m\u00eame travail d&rsquo;investigation scientifique sur le th\u00e8me des particules cosmiques. Pour l\u2019\u00e9dition 2025, quatre \u00e9l\u00e8ves du groupe Sciences+ du lyc\u00e9e ont mesur\u00e9 la dur\u00e9e de vie moyenne du muon dans son r\u00e9f\u00e9rentiel propre. Pour cela, nous avons utilis\u00e9 un [&hellip;]<\/p>\n","protected":false},"author":31,"featured_media":14831,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[184,185],"class_list":["post-14827","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-pole-scientifique","tag-physique","tag-sciences-2"],"_links":{"self":[{"href":"https:\/\/lyceerudloff.com\/index.php\/wp-json\/wp\/v2\/posts\/14827","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lyceerudloff.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lyceerudloff.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lyceerudloff.com\/index.php\/wp-json\/wp\/v2\/users\/31"}],"replies":[{"embeddable":true,"href":"https:\/\/lyceerudloff.com\/index.php\/wp-json\/wp\/v2\/comments?post=14827"}],"version-history":[{"count":4,"href":"https:\/\/lyceerudloff.com\/index.php\/wp-json\/wp\/v2\/posts\/14827\/revisions"}],"predecessor-version":[{"id":14899,"href":"https:\/\/lyceerudloff.com\/index.php\/wp-json\/wp\/v2\/posts\/14827\/revisions\/14899"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lyceerudloff.com\/index.php\/wp-json\/wp\/v2\/media\/14831"}],"wp:attachment":[{"href":"https:\/\/lyceerudloff.com\/index.php\/wp-json\/wp\/v2\/media?parent=14827"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lyceerudloff.com\/index.php\/wp-json\/wp\/v2\/categories?post=14827"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lyceerudloff.com\/index.php\/wp-json\/wp\/v2\/tags?post=14827"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}