{"id":636,"date":"2026-01-22T18:52:07","date_gmt":"2026-01-22T17:52:07","guid":{"rendered":"https:\/\/web.infn.it\/BULLKID-DM\/?page_id=636"},"modified":"2026-01-22T19:14:02","modified_gmt":"2026-01-22T18:14:02","slug":"radio-purity","status":"publish","type":"page","link":"https:\/\/web.infn.it\/BULLKID-DM\/radio-purity\/","title":{"rendered":"Extreme radio-purity"},"content":{"rendered":"\n<p>In order for BULLKID-DM to be capable of detecting such rare events as the recoil of <a href=\"https:\/\/web.infn.it\/BULLKID-DM\/dark-matter\/\" data-type=\"page\" data-id=\"164\">WIMP-like Dark Matter<\/a> particles on the nucler sites of a silicon crystal, it is paramount that the <a href=\"https:\/\/web.infn.it\/BULLKID-DM\/particle-backgrounds\/\" data-type=\"page\" data-id=\"591\">radioactive backgrounds<\/a> are as low as practically possible. Therefore, great care is put towards only introducing radio-pure materials inside the <a href=\"https:\/\/web.infn.it\/BULLKID-DM\/particle-shield\/\" data-type=\"page\" data-id=\"588\">particle shields<\/a> and the <a href=\"https:\/\/web.infn.it\/BULLKID-DM\/bullkid-veto\/\" data-type=\"page\" data-id=\"595\">cryogenic veto<\/a>. <\/p>\n\n\n\n<p>It is critical that the copper of which the detector holders are made and that is used as an innermost shield for BULLKID-DM needs to be of highest purity with low radioactive contaminants. Current measurements point towards the presence of contaminants such as Uranium, Thorium, and Potassium in the few hundreds parts per trillion. Current investigations are ongoing to charaterise the purity rate of the lead intended to be used for the external <a href=\"https:\/\/web.infn.it\/BULLKID-DM\/particle-shield\/\" data-type=\"page\" data-id=\"588\">particle shields<\/a>. Further investrigations are necessary to assess the radio purity of components such as solder, PCBs, electrical connectors, Teflon and the scintillating crystals of the <a href=\"https:\/\/web.infn.it\/BULLKID-DM\/bullkid-veto\/\" data-type=\"page\" data-id=\"595\">cryogenic veto<\/a>. <\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>In order for BULLKID-DM to be capable of detecting such rare events as the recoil of WIMP-like Dark Matter particles on the nucler sites of a silicon crystal, it is paramount that the radioactive backgrounds are as low as practically possible. Therefore, great care is put towards only introducing radio-pure materials inside the particle shields &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/web.infn.it\/BULLKID-DM\/radio-purity\/\" class=\"more-link\">Leggi tutto<span class=\"screen-reader-text\"> &#8220;Extreme radio-purity&#8221;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-636","page","type-page","status-publish","hentry","entry"],"_links":{"self":[{"href":"https:\/\/web.infn.it\/BULLKID-DM\/wp-json\/wp\/v2\/pages\/636","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/web.infn.it\/BULLKID-DM\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/web.infn.it\/BULLKID-DM\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/web.infn.it\/BULLKID-DM\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/web.infn.it\/BULLKID-DM\/wp-json\/wp\/v2\/comments?post=636"}],"version-history":[{"count":4,"href":"https:\/\/web.infn.it\/BULLKID-DM\/wp-json\/wp\/v2\/pages\/636\/revisions"}],"predecessor-version":[{"id":642,"href":"https:\/\/web.infn.it\/BULLKID-DM\/wp-json\/wp\/v2\/pages\/636\/revisions\/642"}],"wp:attachment":[{"href":"https:\/\/web.infn.it\/BULLKID-DM\/wp-json\/wp\/v2\/media?parent=636"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}