title: Evaluation of the new graded Z liner in the Human Monitoring Laboratory's lung counter.
abstract: The Human Monitoring Laboratory has recently completed the graded Z shielding in its lung counting chamber. The addition of a layer of tin and a layer of copper over the existing layer of lead that lined the thick steel walls has improved the background, as confirmed by long counts before and after the shielding was added. The graded Z liner was successful in reducing the general background in the lower energy regions by an average of 16% over the eight regions studied in the range 15-200 keV, over previous values.
authors.affiliation: Human Monitoring Laboratory, Environmental Radiation Hazards Division, Radiation Protection Bureau, 775 Brookfield Road, PL6302D1, Ottawa, Ontario, K1A 1C1 Canada.
authors.forename: Gary H
authors.initials: GH
authors.lastname: Kramer
authors.forename: Barry M
authors.initials: BM
authors.lastname: Hauck
mesh_terms: D016477:Artifacts; D001417:Background Radiation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D008168:Lung / Q000378:metabolism*; D011829:Radiation Dosage; D011868:Radioisotopes / Q000032:analysis* / Q000493:pharmacokinetics*; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors
chemical_list: D011868:Radioisotopes