Table 2.
Sources measured at NIST for this study. Activities (A) for the sources prepared at NIST were determined by triple-to-double coincidence ratio (TDCR) counting. All times are UTC.
| Source ID | t sep | t ref | A/Bq | Technique |
|---|---|---|---|---|
| E2-A1 | 2018–09-14 18:15 | 2018–09-27 17:00 | 1.3121(30) × 106 | TDCR |
| E2-A2 | 2018–09-14 18:15 | 2018–09-27 17:00 | 1.2773(29) × 106 | TDCR |
| E2-D1- A1 | 2018–09-14 18:15 | 2018–09-27 17:00 | 1.2465(28) × 106 | TDCR |
| E3-A2 | 2018–10-31 17:00a | 2018–11-06 17:00 | 1.603(7) × 106 | TDCR |
| E4-A2 | 2019–02-08 20:40 | 2019–02-15 17:00 | 6.073(15) × 106 | TDCR |
| S3-A | 2019–12-04 10:56 | 2019–12-13 12:00 | 1.503(8) × 105b | VIC |
a
The separation time for the E3 source was not communicated by ORNL, but was estimated based on the shipping schedule and observed equilibrium.
b
The comparison ampoule contained 5.01700 g of solution S3 (see Table 1). The activity given here was measured at NIST using the Vinten 671 ionization chamber (VIC).