Utilising a chemically purified solution the radioactive half-life of (227)Th has been determined indirectly by observation of the ingrowth of (223)Ra using an ionisation chamber (IC) and for the first time by direct observation of the change in activity with time using a high-purity germanium (HPGe) γ-ray spectrometer. The radioactive decay was observed for ~104 days (~5.6 half-lives) by γ-ray spectrometry and approximately 63 days and 72 days (~3.4 and ~3.9 half-lives) using an ionisation chamber (IC). The resulting half-life values - 18.695 (4) days (IC) and 18.683 (20) days (HPGe) - are consistent and detailed uncertainty budgets are presented for the two measurement techniques. A weighted mean of our results of 18.695 (4) days is inconsistent with the most precise published half-life value of 18.7176 (52) days (Jordan and Blanke, 1967). A critical evaluation of literature data has been performed, indicating a paucity of reliable and independent measurements. Selected independent published values have been used to determine a recommended half-life of 18.697 (7) days. A method has been introduced in the course of this work so that the recommended half-life of (227)Th as determined by ingrowth can be modified if a different (223)Ra half-life has been determined, evaluated and adopted.
Pharmacology, Toxicology and Pharmaceutical Science
1
7%
Earth and Planetary Sciences
1
7%
Medicine and Dentistry
1
7%
Other
1
7%
Unknown
6
40%
Attention Score in Context
Attention Score in Context
This research output has an Altmetric Attention Score of 3. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 06 July 2022.
All research outputs
#12,344,266
of 34,360,257 outputs
Outputs from Applied Radiation & Isotopes
#654
of 2,148 outputs
Outputs of similar age
#114,085
of 300,421 outputs
Outputs of similar age from Applied Radiation & Isotopes
#9
of 25 outputs
Altmetric has tracked 34,360,257 research outputs across all sources so far. This one is in the 38th percentile – i.e., 38% of other outputs scored the same or lower than it.
So far Altmetric has tracked 2,148 research outputs from this source. They receive a mean Attention Score of 4.2. This one is in the 25th percentile – i.e., 25% of its peers scored the same or lower than it.
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We're also able to compare this research output to 25 others from the same source and published within six weeks on either side of this one. This one is in the 24th percentile – i.e., 24% of its contemporaries scored the same or lower than it.
