title: Radium needle used to calibrate germanium gamma-ray detector.
abstract: A standard platinum-iridium needle that contains 374 MBq 226Ra was tested as a source for calibrating a portable germanium detector used with a gamma-ray spectrometer for environmental radioactivity measurements. The counting efficiencies of the 11 most intense gamma rays emitted by 226Ra and its short-lived radioactive progeny at energies between 186 and 2,448 keV were determined, at the full energy peaks, to construct a curve of counting efficiency vs. energy. The curve was compared to another curve between 43 and 1,596 keV obtained with a NIST mixed-radionuclide standard. It was also compared to the results of a Monte Carlo simulation. The 226Ra source results were consistent with the NIST standard between 248 and 1,596 keV. The Monte Carlo simulation gave a curve parallel to the curve for the combined radium and NIST standard data between 250 and 2,000 keV, but at higher efficiency.
authors.affiliation: Health Physics Program, School of Mechanical Engineering, Georgia Institute of Technology, Atlanta 30332.
authors.forename: S
authors.initials: S
authors.lastname: Kamboj
authors.forename: D
authors.initials: D
authors.lastname: Lovett
authors.forename: B
authors.initials: B
authors.lastname: Kahn
authors.forename: D
authors.initials: D
authors.lastname: Walker
mesh_terms: D002138:Calibration; D005720:Gamma Rays; D005857:Germanium; D009339:Needles; D011874:Radiometry / Q000295:instrumentation*; D011883:Radium
chemical_list: D005857:Germanium; D011883:Radium