{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/42283"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/42283","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"A Bf3 Fast Neutron Dosimeter (Long Counter)","abstract":"A BF3 fast neutron dosimeter or long counter is constructed and calibrated for use with the Cockcroft-Walton accelerator and UTR-IO reactor at Virginia Polytechnic Institute. The counter consists of a paraffin cylinder 8 inches in diameter, having a BF3 proportional detector on the axis and a set of holes around the detector to improve the low energy response. External shields of paraffin, 3 inches thick, and boron-trioxide, 1/2 inch thick, enclose the paraffin cylinder. These shields serve to reduce the background effect and improve the high energy response. Calibration of the counter is accomplished using as neutron sources: plutonium-berylliwn and the induced reactions H2(d,n)He3 and H3(d,n)He4. Long counter efficiencies for both a 1 inch and 1/2 inch BF) tube yield a flat response over the energy range, 2.5 to 4 Mev whereas an approximately 60% decrease in efficiency is observed for a 14.1 Mev neutron. Count rate of long counter is expressed as a function of the incident neutron flux. Neutron fluxes, ranging from 0 to 1100 neutrons/cm2-second are monitored with the counter.","abstract_html":"A BF3 fast neutron dosimeter or long counter is constructed and calibrated for use with the Cockcroft-Walton accelerator and UTR-IO reactor at Virginia Polytechnic Institute. The counter consists of a paraffin cylinder 8 inches in diameter, having a BF3 proportional detector on the axis and a set of holes around the detector to improve the low energy response. External shields of paraffin, 3 inches thick, and boron-trioxide, 1/2 inch thick, enclose the paraffin cylinder. These shields serve to reduce the background effect and improve the high energy response. Calibration of the counter is accomplished using as neutron sources: plutonium-berylliwn and the induced reactions H2(d,n)He3 and H3(d,n)He4. Long counter efficiencies for both a 1 inch and 1/2 inch BF) tube yield a flat response over the energy range, 2.5 to 4 Mev whereas an approximately 60% decrease in efficiency is observed for a 14.1 Mev neutron. Count rate of long counter is expressed as a function of the incident neutron flux. Neutron fluxes, ranging from 0 to 1100 neutrons/cm2-second are monitored with the counter.","abstract_has_math":false,"creators":["Leyland, Walter A."],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Physics","degree_department":"Physics","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1960,"date_issued":"1960-09-03","date_published":"1960-09-03","updated_at":"2026-07-22T22:19:47Z","subjects":[],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-04262010-020346"],"render_values":[{"text":"etd-04262010-020346","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/42283","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Physics"]},{"key":"dc:creator","label":"Author","values":["Leyland, Walter A."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:34:51Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:34:51Z","2010-04-26"]},{"key":"dc:date.issued","label":"Date","values":["1960-09-03"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-04262010-020346"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/42283"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["A BF3 fast neutron dosimeter or long counter is constructed and calibrated for use with the Cockcroft-Walton accelerator and UTR-IO reactor at Virginia Polytechnic Institute. The counter consists of a paraffin cylinder 8 inches in diameter, having a BF3 proportional detector on the axis and a set of holes around the detector to improve the low energy response. External shields of paraffin, 3 inches thick, and boron-trioxide, 1/2 inch thick, enclose the paraffin cylinder. These shields serve to reduce the background effect and improve the high energy response. Calibration of the counter is accomplished using as neutron sources: plutonium-berylliwn and the induced reactions H2(d,n)He3 and H3(d,n)He4. Long counter efficiencies for both a 1 inch and 1/2 inch BF) tube yield a flat response over the energy range, 2.5 to 4 Mev whereas an approximately 60% decrease in efficiency is observed for a 14.1 Mev neutron. Count rate of long counter is expressed as a function of the incident neutron flux. 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