add isotope Bi-207

Author: NuclearPhoenixx

_data/navigation.yml

@@ -19,6 +19,8 @@ isotopes:
         url: /spectrum/Ba-131/
       - title: "Ba-133"
         url: /spectrum/Ba-133/
+      - title: "Bi-207"
+        url: /spectrum/Bi-207/
       - title: "Ceramic Pipe"
         url: /spectrum/CeramicPipe/
       - title: "Co-57"

assets/images/spectra-th/Bi-207.png

@@ -0,0 +1,31 @@
+---
+title: Bismuth-207
+header:
+  teaser: /assets/images/spectra-th/Bi-207.png
+#date: 2022-06-07 21:00:00 +0200
+last_modified_at: 2025-01-03 22:00:00 +0200
+---
+
+Although bismuth-209 is now known to be radioactive, it has classically been considered to be a stable isotope because it has a half-life of approximately 2.01×1019 years, which is more than a billion times the age of the universe. Besides <sup>209</sup>Bi, the most stable bismuth radioisotopes are <sup>210m</sup>Bi with a half-life of 3.04 million years, <sup>208</sup>Bi with a half-life of 368,000 years and <sup>207</sup>Bi, with a half-life of 32.9 years, none of which occurs in nature.
+
+Samples of lichen, moss, soil and air collected since 1961 in Greenland, Svalbard, Iceland, the Faroe Islands, Sweden and Denmark have been remeasured for γ-emitting radionuclides by Ge(Li) spectroscopy. The samples have shown the presence of <sup>207</sup>Bi (physical half-life 38 years), a nuclide which has not been reported earlier in world-wide fallout. The concentrations of <sup>207</sup>Bi have been compared with those of <sup>60</sup>Co, <sup>125</sup>Sb, and <sup>137</sup>Cs. From this comparison the production of <sup>207</sup>Bi is estimated at 1 PBq. It is assumed that the <sup>207</sup>Bi is created in thermonuclear tested explosions in general and that in particular the 55Mt detonation of 30 October 1961 at Novaya Zemlya may have produced this activation product.
+
+### Spectrum ([Fullscreen](/assets/spectra/Bi-207.html))
+
+<iframe width="100%" height="500" src="/assets/spectra/Bi-207.html" title="Bi-207 gamma spectrum" frameborder="0" allowfullscreen></iframe>
+10 minute measurement with a High Purity Germanium (HPGe) radiation detector.
+
+### Metadata
+
+| Isotope:        | Bismuth  |
+| --------------- | -------- |
+| Mass number:    | 207      |
+| Atomic number:  | 83       |
+| Neutron number: | 124      |
+| ...             | ...      |
+
+### Sources and Further Read
+
+- [https://en.wikipedia.org/wiki/Bismuth](https://en.wikipedia.org/wiki/Bismuth)
+- [https://en.wikipedia.org/wiki/Isotopes_of_bismuth](https://en.wikipedia.org/wiki/Isotopes_of_bismuth)
+- [Evidence for bismuth-207 in global fallout](https://www.sciencedirect.com/science/article/abs/pii/0265931X8490002X)