{"id":83440,"date":"2015-04-26T00:30:33","date_gmt":"2015-04-25T21:30:33","guid":{"rendered":"http:\/\/www.fyysika.ee\/?p=83440"},"modified":"2015-05-06T13:37:52","modified_gmt":"2015-05-06T10:37:52","slug":"uhe-elektroni-sunkrotronkiirgus-aitab-maarata-neutriino-massi","status":"publish","type":"post","link":"https:\/\/www.fyysika.ee\/?p=83440","title":{"rendered":"\u00dche elektroni s\u00fcnkrotronkiirgus aitab m\u00e4\u00e4rata neutriino massi?"},"content":{"rendered":"<p>Teadlased on suutnud \u00e4ra m\u00f5\u00f5ta \u00fcksiku magnetv\u00e4ljas ringorbiidil liikuva elektroni kiirguse.\u00a0 Eksperimendis, mida tuntakse ka <a href=\"http:\/\/www.project8.org\/\" target=\"_blank\">Projekt 8<\/a> nime all ja milles osales 27 teadlast\u00a0 kuuest teadusasutusest USA-st ja Saksamaalt, m\u00f5\u00f5deti v\u00e4ga t\u00e4pselt \u00e4ra \u00fcksiku elektroni kiirguse sagedus, mis omakorda annab t\u00e4pse hinnangu elektroni energiale. Kui elektroni energia m\u00f5\u00f5tmise t\u00e4psust \u00f5nnestuks veel parandada, saaks sellistest eksperimentidest hinnata neutriino massi.<\/p>\n<div id=\"attachment_83557\" style=\"width: 310px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/04\/elektron_synkrotron.png\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-83557\" class=\"wp-image-83557 size-medium\" src=\"http:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/04\/elektron_synkrotron-300x300.png\" alt=\"elektron_synkrotron\" width=\"300\" height=\"300\" srcset=\"https:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/04\/elektron_synkrotron-300x300.png 300w, https:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/04\/elektron_synkrotron-150x150.png 150w, https:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/04\/elektron_synkrotron-1024x1024.png 1024w, https:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/04\/elektron_synkrotron.png 1280w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><p id=\"caption-attachment-83557\" class=\"wp-caption-text\">Kasutatud seadme p\u00f5him\u00f5tteskeem.<\/p><\/div>\n<p>Kui elektrilaeng liigub ringorbiidil, siis ta kiirgab elektromagnetkiirgust. See n\u00e4htus on aluseks <a href=\"http:\/\/www.fyysika.ee\/?p=53753\" target=\"_blank\">s\u00fcnkrotronkiirguse <\/a>saamisel ja \u00fcheks p\u00f5hjuseks, miks planetaarne aatomi mudel \u00fcsna kiiresti k\u00f5rvale heideti <a href=\"http:\/\/opik.fyysika.ee\/index.php\/book\/view\/3#genericSection1372\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/02\/icon_eopik.png\" alt=\"icon_eopik\" width=\"23\" height=\"19\" \/><\/a>. Aga kui s\u00fcnkrotronides kiirgavad \u00fcheaegselt paljud elektronid, siis Projekt 8-s suudeti tekitada olukord, kus registreeriti \u00fche elektroni s\u00fcnkrotronkiirgus.<\/p>\n<p>Kasutatud seadme (vt joonis) p\u00f5hiosaks on 1T \u00fclijuhtiva magneti sisse paigutatud v\u00e4ike gaasirakk. Rakk sisaldab gaasilise kr\u00fcptoon-83\u00a0 molekule, mille beetalagunemisel tekivad elektronid. Kuna lagunemine toimub magnetv\u00e4ljas hakkavad tekkinud elektronid liikuma ringorbiitidel <a href=\"http:\/\/opik.fyysika.ee\/index.php\/book\/view\/15#genericSection1447\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone\" src=\"http:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/02\/icon_eopik.png\" alt=\"icon_eopik\" width=\"23\" height=\"19\" \/><\/a> ja kiirgama ca 25 GHz sagedusega elektromagnetlaineid, mis siis v\u00e4ga tundlike mikrolainete v\u00f5imenditega registreeritakse.<\/p>\n<div id=\"attachment_83456\" style=\"width: 310px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/05\/e36_2.png\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-83456\" class=\"wp-image-83456 size-medium\" src=\"http:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/05\/e36_2-300x208.png\" alt=\"e36_2\" width=\"300\" height=\"208\" srcset=\"https:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/05\/e36_2-300x208.png 300w, https:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/05\/e36_2.png 900w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><p id=\"caption-attachment-83456\" class=\"wp-caption-text\">Eksperimendist kiiratud elektromagnetv\u00e4lja tugevuse s\u00f5ltuvus ajast ja sagedusest. Pilt: D. M. Asner et al. Phys.Rev.Lett<\/p><\/div>\n<p>Uurijatel \u00f5nnestus m\u00f5\u00f5ta eksperimendist kiiratud elektromagnetv\u00e4lja tugevuse s\u00f5ltuvana ajast ja sagedusest (vt teist pilti). Heledad, \u00fclespoole kaldu jooned n\u00e4itavad elektronide poolt kiiratud elektromagnetlaineid. Kuidas sellest pildist aru saada?<\/p>\n<p>Kui elektronid kiirgavad elektromagnetlaineid, siis nad paratamatult kaotavad energiat, nende p\u00f6\u00f6rlemise raadius v\u00e4heneb, samas sagedus suureneb. Kusjuures ennustatav sageduse suurenemine on samamoodi lineaarne, kui k\u00e4esolevas eksperimendis m\u00f5\u00f5detud (h\u00fcpped k\u00f5rgemate sageduste poole on p\u00f5hjustatud elektronide p\u00f5rkumisest gaasi rakus olevate aatomite ja molekulidega). Teadlased suutsid elektroni energia \u00e4ra m\u00f5\u00f5ta t\u00e4psusega 30 elektronvolti.<\/p>\n<div id=\"attachment_83460\" style=\"width: 264px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/05\/newtabletopd.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-83460\" class=\"wp-image-83460 size-medium\" src=\"http:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/05\/newtabletopd-254x300.jpg\" alt=\"newtabletopd\" width=\"254\" height=\"300\" srcset=\"https:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/05\/newtabletopd-254x300.jpg 254w, https:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/05\/newtabletopd.jpg 358w\" sizes=\"auto, (max-width: 254px) 100vw, 254px\" \/><\/a><p id=\"caption-attachment-83460\" class=\"wp-caption-text\">Selline n\u00e4eb v\u00e4lja kasutatud seade. Foto: Phys.org<\/p><\/div>\n<p>Aga see eksperiment ei ole teps mitte p\u00fcsti pandud nende peaaegu et koolif\u00fc\u00fcsika tasemel teadmiste t\u00f5estamiseks. Eesm\u00e4rgiks on hoopis\u00a0 neutriinode massi m\u00f5\u00f5tmine. Neutriino mass on kahtlemata teema, mis v\u00e4\u00e4rib omaette k\u00e4sitlust. Siinkohal nendime lihtsalt, et neutriino massi alampiiriks on t\u00e4na hinnatud 0.01-0.05eV\/c<sup>2<\/sup>, samas kui &#8220;kerguselt&#8221; j\u00e4rgmise fermioni, elektroni, mass on &gt;500000eV\/c<sup>2<\/sup> . Nii et neutriino on t\u00f5epoolest v\u00e4ga-v\u00e4ga kerge (pikka aega arvati, et tal ei olegi seisumassi) ning j\u00e4relikult ka raskesti m\u00f5\u00f5detav.<\/p>\n<p>Aga kuidas saab hinnata neutriino massi, kui registreeritakse elektronide kiiratud elektromagnetlaineid? Kiirguse algp\u00f5hjus on beetalagunemine. Beetalagunemisel peab kehtima energia ja impulsi j\u00e4\u00e4vuse seadus. See ei ole v\u00f5imalik teisiti, kui iga beeta-lagunemise k\u00e4igus kiiratakse ka neutriino <a href=\"http:\/\/opik.fyysika.ee\/index.php\/book\/view\/32#genericSection1638\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/www.fyysika.ee\/wp-content\/uploads\/2015\/02\/icon_eopik.png\" alt=\"icon_eopik\" width=\"23\" height=\"19\" \/><\/a>. Eksperimendis m\u00f5\u00f5detakse \u00e4ra elektroni energia ning v\u00f5rreldakse seda beetalagunemise koguenergiaga. Kui neutriinol on mass, siis ei saa elektroni energia v\u00f5rduda lagunemise koguenergiaga, sest osa energiast peab minema neutriino seisumassi tekitamiseks (vana hea E=mc<sup>2<\/sup>). J\u00e4relikult saab neutriino massi hinnata lagunemises tekkiva maksimaalse energiaga elektroni energia kaudu.<\/p>\n<p>Allikad:<\/p>\n<p><a href=\"http:\/\/physics.aps.org\/articles\/v8\/36?referer=rss\">http:\/\/physics.aps.org\/articles\/v8\/36?referer=rss<\/a><\/p>\n<p><a href=\"http:\/\/journals.aps.org\/prl\/abstract\/10.1103\/PhysRevLett.114.162501\">http:\/\/journals.aps.org\/prl\/abstract\/10.1103\/PhysRevLett.114.162501<\/a><\/p>\n<p><a href=\"http:\/\/phys.org\/news\/2015-04-tabletop-detector-electrons.html?utm_source=menu&amp;utm_medium=link&amp;utm_campaign=item-menu\">http:\/\/phys.org\/news\/2015-04-tabletop-detector-electrons.html<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Teadlased on suutnud \u00e4ra m\u00f5\u00f5ta \u00fcksiku magnetv\u00e4ljas ringorbiidil liikuva elektroni kiirguse.\u00a0 Eksperimendis, mida tuntakse ka Projekt 8 nime all ja milles osales 27 teadlast\u00a0 kuuest teadusasutusest USA-st ja Saksamaalt, m\u00f5\u00f5deti v\u00e4ga t\u00e4pselt \u00e4ra \u00fcksiku elektroni kiirguse sagedus, mis omakorda annab t\u00e4pse hinnangu elektroni energiale. Kui elektroni energia m\u00f5\u00f5tmise t\u00e4psust \u00f5nnestuks veel parandada, saaks sellistest eksperimentidest [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":83456,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[16],"tags":[],"class_list":{"0":"post-83440","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-teadusuudis","8":"entry"},"_links":{"self":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/83440","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=83440"}],"version-history":[{"count":0,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/83440\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/media\/83456"}],"wp:attachment":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=83440"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=83440"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=83440"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}