{"id":895,"date":"2022-08-09T09:03:48","date_gmt":"2022-08-09T09:03:48","guid":{"rendered":"https:\/\/www.shalomeo.com\/blog\/?p=895"},"modified":"2022-08-09T09:03:48","modified_gmt":"2022-08-09T09:03:48","slug":"plastic-scintillator-response-to-low-energy-photons","status":"publish","type":"post","link":"https:\/\/www.shalomeo.com\/blog\/plastic-scintillator-response-to-low-energy-photons\/895.html","title":{"rendered":"Plastic scintillator response to low-energy photons"},"content":{"rendered":"\n<p>The plastic scintillator is a promising dosimeter for brachytherapy and other low-energy photon applications because of its high sensitivity and approximate tissue equivalence. As part of our project to develop a new plastic scintillator material which maximizes sensitivity and radiological equivalence to water, we have measured the response, \u03b5 (light output\/unit air kerma), of plastic scintillator to low-energy bremsstrahlung (20 to 57 keV average energies) x-rays as well as photons emitted by 99mTc, 192Ir, and 137Cs sources, all of which were calibrated in terms of air kerma.<\/p>\n\n\n\n<p>The plastic scintillator systems studied were a standard commercial <strong><a href=\"https:\/\/www.shalomeo.com\/Scintillators\/Plastic-Scintillators\" target=\"_blank\" rel=\"noreferrer noopener\">plastic scintillator<\/a><\/strong>, BC400 (Bicron Corporation, Newbury, OH), and our new sensitive and quench-resistant scintillator (polyvinyltoluene base and binary dye system) with and without 4% Cl loading intended to match the effective atomic number of water. For low-energy x-rays; \u03b5 was 20-57% relative to \u03b5 for 192Ir photons. Chlorine loading clearly reduced the energy dependence of \u03b5, which ranged from 46% to 85% relative to 192Ir. However, even after using Monte Carlo photon-transport simulation to correct for the non-air equivalence of the plastic scintillator, inherent dosimetric sensitivity still varied by 30% over the 20-400 keV energy range.<\/p>\n\n\n\n<p>Our work, one of the few measurements of plastic scintillator response to low-energy photons, appears to confirm Birks&#8217; 1955 finding that ionization quenching reduces sensitivity to electrons below 125 keV. However, our results cannot be explained by Birks&#8217; widely used unimolecular quenching model.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The plastic scintillator is a promising dosimeter  &hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[2],"tags":[22],"_links":{"self":[{"href":"https:\/\/www.shalomeo.com\/blog\/wp-json\/wp\/v2\/posts\/895"}],"collection":[{"href":"https:\/\/www.shalomeo.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.shalomeo.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.shalomeo.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.shalomeo.com\/blog\/wp-json\/wp\/v2\/comments?post=895"}],"version-history":[{"count":0,"href":"https:\/\/www.shalomeo.com\/blog\/wp-json\/wp\/v2\/posts\/895\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.shalomeo.com\/blog\/wp-json\/wp\/v2\/media?parent=895"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.shalomeo.com\/blog\/wp-json\/wp\/v2\/categories?post=895"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.shalomeo.com\/blog\/wp-json\/wp\/v2\/tags?post=895"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}