Bismuth-214 (Bi-214) is a radioactive isotope of bismuth with a half-life of approximately 19.9 minutes. It is part of the uranium-238 decay series, formed as a decay product of radon-222 through polonium-218 and lead-214. Bi-214 decays primarily via beta emission to polonium-214, accompanied by strong gamma radiation at characteristic energies, making it highly detectable using gamma spectrometry.
This isotope is almost always present in a mixture with other isotopes characteristic of the decay chain of uranium, radium or radon.
Bi-214 is widely used in environmental monitoring and radiation detection calibration due to its strong gamma emissions. In research, Bi-214 is studied to understand decay chains and natural radiation distribution. It also plays a role in validating radiation models and monitoring radon progeny in indoor air quality studies.
Bi-214 is naturally found as part of the uranium-238 decay chain and is present in trace amounts in environments with uranium-bearing minerals, such as uraninite and pitchblende. It is commonly encountered in soils, rocks, and groundwater in areas with high uranium content. Bi-214 is also found in the atmosphere as a decay product of radon-222, contributing to natural background radiation. Its strong gamma emissions make it a critical component in environmental radiation monitoring and uranium exploration.


Bi-214
Bismuth-214
Half-life: 19.9 min Main emission lines: 609, 1120, 1760 keV Decay chain: Ra-226 Related lines: 47, 78, 186, 242, 295, 351, 2200 keV
Decay mode Alpha
Alpha
Energy, keV | Intensity, % |
5452 | 0.0113 |
5516 | 0.0082 |
5273 | 0.00122 |
5184 | 0.000128 |
Decay mode Beta-
Beta-
Avg. En., keV | Intensity, % | Decay En., keV |
1268 | 19.2 | (3269) |
539 | 17.55 | (1539) |
525 | 16.90 | (1504) |
492 | 8.16 | (1422) |
683 | 7.22 | (1891) |
352 | 5.56 | (1065) |
385 | 4.33 | (1150) |
615 | 3.09 | (1726) |
261 | 2.78 | (821) |
424 | 2.459 | (1252) |
475 | 1.589 | (1379) |
427 | 1.433 | (1258) |
248 | 1.28 | (787) |
433 | 1.192 | (1274) |
668 | 0.90 | (1853) |
356 | 0.866 | (1076) |
567 | 0.57 | (1608) |
318 | 0.563 | (976) |
1007 | 0.55 | (2660) |
161 | 0.542 | (540) |
373 | 0.46 | (1121) |
165 | 0.273 | (550) |
173 | 0.249 | (574) |
350 | 0.22 | (1060) |
204 | 0.20 | (664) |
328 | 0.192 | (1003) |
Gamma
Energy, keV | Intensity, % |
609.321 | 45.44 |
1764.491 | 15.29 |
1120.294 | 14.90 |
1238.122 | 5.83 |
2204.10 | 4.92 |
768.360 | 4.89 |
1377.669 | 3.985 |
934.056 | 3.094 |
1729.595 | 2.87 |
1407.988 | 2.388 |
1509.211 | 2.127 |
1847.433 | 2.027 |
1155.210 | 1.634 |
2447.69 | 1.545 |
665.446 | 1.540 |
1280.976 | 1.435 |
1401.515 | 1.333 |
806.179 | 1.262 |
2118.51 | 1.156 |
1661.274 | 1.046 |
1385.310 | 0.801 |
1583.203 | 0.708 |
703.10 | 0.482 |
X-rays
Energy, keV | Intensity, % |
79.290 | 0.686 |
9.655 - 16.929 | 0.61 |
76.862 | 0.412 |
89.254 - 92.628 | 0.310 |
89.254 - 90.419 | 0.236 |
92.248 - 92.382 | 0.0735 |