{"id":14674,"date":"2024-10-16T21:40:48","date_gmt":"2024-10-16T21:40:48","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/astm-e481\/"},"modified":"2024-10-24T12:03:43","modified_gmt":"2024-10-24T12:03:43","slug":"astm-e481","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/astm\/astm-e481\/","title":{"rendered":"ASTM-E481"},"content":{"rendered":"

ASTM E481-10<\/h3>\n

Historical Standard: Standard Test Method for Measuring Neutron Fluence Rate by Radioactivation of Cobalt and Silver<\/h4>\n
\n

ASTM E481<\/h4>\n

Scope<\/strong><\/p>\n

1.1 This test method covers a suitable means of obtaining the thermal neutron fluence rate, or fluence, in well moderated nuclear reactor environments where the use of cadmium, as a thermal neutron shield as described in Method E262, is undesirable because of potential spectrum perturbations or of temperatures above the melting point of cadmium.<\/p>\n

1.2 This test method describes a means of measuring a Westcott neutron fluence rate (Note 1) by activation of cobalt- and silver-foil monitors (See Terminology E170). The reaction 59<\/sup>Co(n,\u03b3<\/span><\/span>)60<\/sup>Co results in a well-defined gamma emitter having a half-life of 1925.28 days (1)<\/span>. The reaction 109<\/sup>Ag(n,\u02d9<\/span>\u03b3<\/span>) 110m<\/sup>Ag results in a nuclide with a complex decay scheme which is well known and having a half-life of 249.76 days (1)<\/span>. Both cobalt and silver are available either in very pure form or alloyed with other metals such as aluminum. A reference source of cobalt in aluminum alloy to serve as a neutron fluence rate monitor wire standard is available from the National Institute of Standards and Technology (NIST) as Standard Reference Material 953. The competing activities from neutron activation of other isotopes are eliminated, for the most part, by waiting for the short-lived products to die out before counting. With suitable techniques, thermal neutron fluence rate in the range from 109<\/sup> cm\u2212<\/span>2<\/sup> \u00b7<\/span> s\u2212<\/span>1<\/sup> to 3 \u00d7<\/span> 1015<\/sup> cm\u2212<\/span>2<\/sup> \u00b7<\/span> s\u2212<\/span>1<\/sup> can be measured. For this method to be applicable, the reactor must be well moderated and be well represented by a Maxwellian low-energy distribution and an (1\/E<\/span>) epithermal distribution. These conditions are usually met in positions surrounded by hydrogenous moderator without nearby strongly absorbing materials. Otherwise the true spectrum must be calculated to obtain effective activation cross sections over all energies.<\/p>\n

Keywords<\/strong><\/p>\n

activation; cobalt; dosimetry; foil; silver; thermal neutron; Cobalt- and silver-foil monitors; Fluence; Neutron activation reactions; Neutron flux\/fluence; Radioactivation–fast neutron flux; Silver-foil monitors; Thermal neutron flux<\/p>\n

ICS Code<\/strong><\/p>\n

ICS Number Code 17.240 (Radiation measurements)<\/p>\n

DOI:<\/strong> 10.1520\/E0481-10<\/p>\n<\/div>\n

PDF Catalog<\/h4>\n\n\n\n\n\n\n\n\n
PDF Pages<\/th>\nPDF Title<\/th>\n<\/tr>\n
1<\/td>\nScope
Referenced Documents
Significance and Use <\/td>\n<\/tr>\n
2<\/td>\nApparatus
Materials and Manufacture
Procedure
TABLE 1 <\/td>\n<\/tr>\n
3<\/td>\nCalculation
TABLE 2
TABLE 3 <\/td>\n<\/tr>\n
4<\/td>\nFIG. 1 <\/td>\n<\/tr>\n
5<\/td>\nTABLE 4 <\/td>\n<\/tr>\n
6<\/td>\nPrecision and Bias
Keywords
REFERENCES <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

E481-10 Standard Test Method for Measuring Neutron Fluence Rate by Radioactivation of Cobalt and Silver<\/b><\/p>\n\n\n\n\n
Published By<\/td>\nPublication Date<\/td>\nNumber of Pages<\/td>\n<\/tr>\n
ASTM<\/b><\/a><\/td>\n2010<\/td>\n7<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":14675,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[2637],"product_tag":[],"class_list":{"0":"post-14674","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-astm","8":"first","9":"instock","10":"sold-individually","11":"shipping-taxable","12":"purchasable","13":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/14674","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/14675"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=14674"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=14674"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=14674"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}