{"id":588,"date":"2026-01-22T14:55:40","date_gmt":"2026-01-22T13:55:40","guid":{"rendered":"https:\/\/web.infn.it\/BULLKID-DM\/?page_id=588"},"modified":"2026-01-22T18:52:33","modified_gmt":"2026-01-22T17:52:33","slug":"particle-shield","status":"publish","type":"page","link":"https:\/\/web.infn.it\/BULLKID-DM\/particle-shield\/","title":{"rendered":"Particle Shield"},"content":{"rendered":"\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:33.33%\">\n<p>Burying the experiment under over 1km of solid rock is not sufficient in order to reduce the particle background to a level that allows BULLKID-DM to conduct its search for WIMP-like Dark Matter. Our simulations show that it is necessary to further reduce the impact of the radioactive sources that are naturally present inside the LNGS experimental Hall due to the composition of its rocky walls. In order to do that two main shields have been envisioned: one at room temperature that encloses the cryostat and one at cryogenic temperature.<\/p>\n\n\n\n<p>The inner veto consists of over 250 kg of copper, including 70 kg of copper of<a href=\"https:\/\/web.infn.it\/BULLKID-DM\/radio-purity\/\" data-type=\"page\" data-id=\"636\"> extreme radio-purity<\/a>. Furthermore, the shield consists of a boron-carbide layer to further slow down the radiogenic neutrons and an <a href=\"https:\/\/web.infn.it\/BULLKID-DM\/bullkid-veto\/\" data-type=\"page\" data-id=\"595\">anti-coincidence (veto) detector.<\/a><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:66.66%\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1005\" height=\"565\" src=\"https:\/\/web.infn.it\/BULLKID-DM\/wp-content\/uploads\/2026\/01\/immagine-6.png\" alt=\"\" class=\"wp-image-617\" srcset=\"https:\/\/web.infn.it\/BULLKID-DM\/wp-content\/uploads\/2026\/01\/immagine-6.png 1005w, https:\/\/web.infn.it\/BULLKID-DM\/wp-content\/uploads\/2026\/01\/immagine-6-300x169.png 300w, https:\/\/web.infn.it\/BULLKID-DM\/wp-content\/uploads\/2026\/01\/immagine-6-768x432.png 768w\" sizes=\"auto, (max-width: 1005px) 100vw, 1005px\" \/><figcaption class=\"wp-element-caption\"><strong>The outher shield will consist of a 20 cm lead enclosure with added copper to shield from the natural radioactivity of the lead and polyethylene to moderate the neutrons that are originated from radioactive sources. <\/strong><\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"616\" height=\"772\" src=\"https:\/\/web.infn.it\/BULLKID-DM\/wp-content\/uploads\/2026\/01\/immagine-7.png\" alt=\"\" class=\"wp-image-618\" style=\"width:666px;height:auto\" srcset=\"https:\/\/web.infn.it\/BULLKID-DM\/wp-content\/uploads\/2026\/01\/immagine-7.png 616w, https:\/\/web.infn.it\/BULLKID-DM\/wp-content\/uploads\/2026\/01\/immagine-7-239x300.png 239w\" sizes=\"auto, (max-width: 616px) 100vw, 616px\" \/><figcaption class=\"wp-element-caption\"><strong>The BULLKID internal cryogenic shield consists of over 250 kg of copper, 70 kg of which are made of copper of extreme purity.<\/strong><\/figcaption><\/figure>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Burying the experiment under over 1km of solid rock is not sufficient in order to reduce the particle background to a level that allows BULLKID-DM to conduct its search for WIMP-like Dark Matter. Our simulations show that it is necessary to further reduce the impact of the radioactive sources that are naturally present inside the &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/web.infn.it\/BULLKID-DM\/particle-shield\/\" class=\"more-link\">Leggi tutto<span class=\"screen-reader-text\"> &#8220;Particle Shield&#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-588","page","type-page","status-publish","hentry","entry"],"_links":{"self":[{"href":"https:\/\/web.infn.it\/BULLKID-DM\/wp-json\/wp\/v2\/pages\/588","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=588"}],"version-history":[{"count":6,"href":"https:\/\/web.infn.it\/BULLKID-DM\/wp-json\/wp\/v2\/pages\/588\/revisions"}],"predecessor-version":[{"id":639,"href":"https:\/\/web.infn.it\/BULLKID-DM\/wp-json\/wp\/v2\/pages\/588\/revisions\/639"}],"wp:attachment":[{"href":"https:\/\/web.infn.it\/BULLKID-DM\/wp-json\/wp\/v2\/media?parent=588"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}