{"id":221961,"date":"2016-05-16T02:00:00","date_gmt":"2016-05-15T23:00:00","guid":{"rendered":"http:\/\/www.fyysika.ee\/?guid=067ecd90c47b2c44d1a36d2eb88f1823"},"modified":"2016-05-16T02:00:00","modified_gmt":"2016-05-15T23:00:00","slug":"energetic-photons-through-water-an-undergraduate-experiment-with-correlated-%ce%b3-rays-from-22-na","status":"publish","type":"post","link":"https:\/\/www.fyysika.ee\/?p=221961","title":{"rendered":"Energetic photons through water: an undergraduate experiment with correlated \u03b3 -rays from 22 Na"},"content":{"rendered":"<p>Measurements of the speed of light have been carried out in the past by the correlation between<br \/>\ngamma rays detected in two scintillation detectors. To demonstrate that the speed of gamma rays in a<br \/>\ntransparent medium is very close to that observed in the vacuum, a time-of-flight experiment was<br \/>\norganized in an educational context with undergraduate students, making use of two BaF 2 detectors<br \/>\nand a small intensity 22 Na source. Measurements of time-of-flight spectra were carried out for<br \/>\nseveral values of the distance between the two detectors, allowing us to extract the speed of<br \/>\nphotons in air. A measurement was also done with an amount of water along the photon path and the<br \/>\nresult compared with that obtained in air. Various experimental aspects of the interaction of gammas<br \/>\nwith the detectors were finally addressed through GEANT simulations of the setup to interpret the<br \/>\nresults.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Measurements of the speed of light have been carried out in the past by the correlation between<br \/>\ngamma rays detected in two scintillation detectors. To demonstrate that the speed of gamma rays in a<br \/>\ntransparent medium is very close to that observed in &#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","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":[178],"tags":[],"class_list":{"0":"post-221961","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-rss-fuusikaharidus","7":"entry"},"_links":{"self":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/221961","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=221961"}],"version-history":[{"count":0,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/221961\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=221961"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=221961"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=221961"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}