Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8208488 | Applied Radiation and Isotopes | 2018 | 8 Pages |
Abstract
The half-life of 99â¯mTc was measured at the JRC using the ionisation chamber 'IC1' (type Centronic IG12). The result, T1/2(99â¯mTc)â¯=â¯6.00660 (18) h, is in good agreement with literature data. One experiment was performed in IC1's default set-up with the ionisation current being integrated over an air capacitor and read out as a voltage increase over time. This ensured excellent linearity and precision throughout the dynamic range, but the maximum current was limited to 2â¯nA. In a second test, the current was directly read out with a Keithley 6517â¯A electrometer. Applying correction factors for the automatic range switching of the electrometer, an acceptable linearity was demonstrated over a range of 12 half-life periods starting at 20â¯nA. Range switching and autocorrelation of the current readout increase the systematic and random error propagation factors. Piecewise fitting of the decay curve over periods of 6â¯h yields the same 99â¯mTc half-life value within 0.04% (0.0025â¯h) standard deviation over an activity range spanning at least 10 half-life periods (3 orders of magnitude).
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Radiation
Authors
S. Pommé, J. Paepen, R. Van Ammel,