<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>T. A. Farley</dc:contributor>
  <dc:contributor>N. Lazar</dc:contributor>
  <dc:creator>F. E. Senftle</dc:creator>
  <dc:date>1956</dc:date>
  <dc:description>&lt;p&gt;The half-life of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="aps-inline-formula"&gt;&lt;span id="MathJax-Element-3-Frame" class="mjx-chtml MathJax_CHTML"&gt;&lt;span id="MJXc-Node-17" class="mjx-math"&gt;&lt;span id="MJXc-Node-18" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-19" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-20" class="mjx-msup"&gt;&lt;span class="mjx-base"&gt;&lt;span id="MJXc-Node-21" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-22" class="mjx-mi"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;Th&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;sup&gt;&lt;span class="mjx-sup"&gt;&lt;span id="MJXc-Node-23" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-24" class="mjx-mn"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;232&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/sup&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;has been calculated by determining an absolute gamma-disintegration rate for&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="aps-inline-formula"&gt;&lt;span id="MathJax-Element-4-Frame" class="mjx-chtml MathJax_CHTML"&gt;&lt;span id="MJXc-Node-25" class="mjx-math"&gt;&lt;span id="MJXc-Node-26" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-27" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-28" class="mjx-msup"&gt;&lt;span class="mjx-base"&gt;&lt;span id="MJXc-Node-29" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-30" class="mjx-mi"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;Tl&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;sup&gt;&lt;span class="mjx-sup"&gt;&lt;span id="MJXc-Node-31" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-32" class="mjx-mn"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;208&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/sup&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;in equilibrium with&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="aps-inline-formula"&gt;&lt;span id="MathJax-Element-5-Frame" class="mjx-chtml MathJax_CHTML"&gt;&lt;span id="MJXc-Node-33" class="mjx-math"&gt;&lt;span id="MJXc-Node-34" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-35" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-36" class="mjx-msup"&gt;&lt;span class="mjx-base"&gt;&lt;span id="MJXc-Node-37" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-38" class="mjx-mi"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;Th&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;sup&gt;&lt;span class="mjx-sup"&gt;&lt;span id="MJXc-Node-39" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-40" class="mjx-mn"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;232&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/sup&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;for three old thorium nitrate salts and one natural thorite sample. The branching ratio,&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="aps-inline-formula"&gt;&lt;span id="MathJax-Element-6-Frame" class="mjx-chtml MathJax_CHTML"&gt;&lt;span id="MJXc-Node-41" class="mjx-math"&gt;&lt;span id="MJXc-Node-42" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-43" class="mjx-mfrac"&gt;&lt;span class="mjx-box MJXc-stacked"&gt;&lt;span class="mjx-numerator"&gt;&lt;span id="MJXc-Node-44" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-45" class="mjx-mi"&gt;&lt;span class="mjx-char MJXc-TeX-math-I"&gt;α/&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class="mjx-denominator"&gt;&lt;span id="MJXc-Node-46" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-47" class="mjx-mo"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;(&lt;/span&gt;&lt;/span&gt;&lt;span id="MJXc-Node-48" class="mjx-mi"&gt;&lt;span class="mjx-char MJXc-TeX-math-I"&gt;α&lt;/span&gt;&lt;/span&gt;&lt;span id="MJXc-Node-49" class="mjx-mo"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;+&lt;/span&gt;&lt;/span&gt;&lt;span id="MJXc-Node-50" class="mjx-mi"&gt;&lt;span class="mjx-char MJXc-TeX-math-I"&gt;β&lt;/span&gt;&lt;/span&gt;&lt;span id="MJXc-Node-51" class="mjx-mo"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;)&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;, for&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="aps-inline-formula"&gt;&lt;span id="MathJax-Element-7-Frame" class="mjx-chtml MathJax_CHTML"&gt;&lt;span id="MJXc-Node-52" class="mjx-math"&gt;&lt;span id="MJXc-Node-53" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-54" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-55" class="mjx-msup"&gt;&lt;span class="mjx-base"&gt;&lt;span id="MJXc-Node-56" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-57" class="mjx-mi"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;Bi&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;sup&gt;&lt;span class="mjx-sup"&gt;&lt;span id="MJXc-Node-58" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-59" class="mjx-mn"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;212&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/sup&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;, a necessary parameter in the calculation, was also measured. The half-life of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="aps-inline-formula"&gt;&lt;span id="MathJax-Element-8-Frame" class="mjx-chtml MathJax_CHTML"&gt;&lt;span id="MJXc-Node-60" class="mjx-math"&gt;&lt;span id="MJXc-Node-61" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-62" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-63" class="mjx-msup"&gt;&lt;span class="mjx-base"&gt;&lt;span id="MJXc-Node-64" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-65" class="mjx-mi"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;Th&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;sup&gt;&lt;span class="mjx-sup"&gt;&lt;span id="MJXc-Node-66" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-67" class="mjx-mn"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;232&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/sup&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;was found to be 1.42×&lt;span class="aps-inline-formula"&gt;&lt;span id="MathJax-Element-9-Frame" class="mjx-chtml MathJax_CHTML"&gt;&lt;span id="MJXc-Node-68" class="mjx-math"&gt;&lt;span id="MJXc-Node-69" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-70" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-71" class="mjx-msup"&gt;&lt;span class="mjx-base"&gt;&lt;span id="MJXc-Node-72" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-73" class="mjx-mn"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;10&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;sup&gt;&lt;span class="mjx-sup"&gt;&lt;span id="MJXc-Node-74" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-75" class="mjx-mn"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;10&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/sup&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;years within an estimated error of 5%, which is essentially in agreement with the presently accepted value. The branching ratio,&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="aps-inline-formula"&gt;&lt;span id="MathJax-Element-10-Frame" class="mjx-chtml MathJax_CHTML"&gt;&lt;span id="MJXc-Node-76" class="mjx-math"&gt;&lt;span id="MJXc-Node-77" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-78" class="mjx-mfrac"&gt;&lt;span class="mjx-box MJXc-stacked"&gt;&lt;span class="mjx-numerator"&gt;&lt;span id="MJXc-Node-79" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-80" class="mjx-mi"&gt;&lt;span class="mjx-char MJXc-TeX-math-I"&gt;α/&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class="mjx-denominator"&gt;&lt;span id="MJXc-Node-81" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-82" class="mjx-mo"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;(&lt;/span&gt;&lt;/span&gt;&lt;span id="MJXc-Node-83" class="mjx-mi"&gt;&lt;span class="mjx-char MJXc-TeX-math-I"&gt;α&lt;/span&gt;&lt;/span&gt;&lt;span id="MJXc-Node-84" class="mjx-mo"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;+&lt;/span&gt;&lt;/span&gt;&lt;span id="MJXc-Node-85" class="mjx-mi"&gt;&lt;span class="mjx-char MJXc-TeX-math-I"&gt;β&lt;/span&gt;&lt;/span&gt;&lt;span id="MJXc-Node-86" class="mjx-mo"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;)&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;, of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="aps-inline-formula"&gt;&lt;span id="MathJax-Element-11-Frame" class="mjx-chtml MathJax_CHTML"&gt;&lt;span id="MJXc-Node-87" class="mjx-math"&gt;&lt;span id="MJXc-Node-88" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-89" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-90" class="mjx-msup"&gt;&lt;span class="mjx-base"&gt;&lt;span id="MJXc-Node-91" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-92" class="mjx-mi"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;Bi&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;sup&gt;&lt;span class="mjx-sup"&gt;&lt;span id="MJXc-Node-93" class="mjx-mrow"&gt;&lt;span id="MJXc-Node-94" class="mjx-mn"&gt;&lt;span class="mjx-char MJXc-TeX-main-R"&gt;212&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/sup&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;was found to be 0.362±0.006, about 7.4% higher than the currently accepted value.&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1103/PhysRev.104.1629</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>American Physical Society</dc:publisher>
  <dc:title>Half-life of Th232 and the branching ratio of Bi212</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>