TY  - BOOK
AU  - Lee,R.M.
AU  - Loftus,T.P.
TI  - Correction Factors for the Calibration of Encapsulated Radium Sources
PY  - 1962///
PB  - [Gaithersburg, MD] : U.S. Dept. of Commerce, National Institute of Standards and Technology, 
KW  - Text
KW  - local
N1  - /pmc/articles/PMC5315329
N2  - Several aspects of the procedure and corrections for the calibration of encapsulated radium sources at NBS have recently been investigated. It was found that a chamber equipped with a guard-ring type electrode system allowing the use of a vibrating reed electrometer as a current detector provides more versatility and precision than the gold-leaf electroscope now in use for routine calibrations. Absorption corrections for the U.S. primary national radium standards have been determined for the NBS chamber: 0.78 percent for standard 5440 and 1.01 percent for standard 5437. The Owen-Naylor integral equation for absorption of rays in the walls of cylindrical radium sources has been evaluated by a power series expansion of the integrand. Absorption coefficients and correction factors for platinum and Moael metal (materials commonly used for source capsules) have been computed for the NBS chamber
UR  - http://dx.doi.org/10.6028/jres.066A.011
ER  -