Delayed nuclear radiation

From Wikipedia, the free encyclopedia

Delayed nuclear radiation can occur in a nuclear decay. It happens when an isotope decays into a very short-lived isotope and then decays again to a relatively long-lived isotope. The short-lived isotope is usually a meta-stable nuclear isomer.

For example, Gallium-73 decays via beta decay into Germanium-73m which is very short-lived. The Germanium isotope emits two weak gamma rays and a conversion electron.

\mathrm{{}^{73}Ga}\rightarrow\mathrm{{}^{73m}Ge}+2\mathrm{\gamma{}}\rightarrow\mathrm{{}^{73}Ge}+2\mathrm{\gamma{}}+\mathrm{e}^-

Because the middle isotope is so short-lived, the gamma rays are considered part of the Gallium decay. Therefore the above equation is simplified.

\mathrm{{}^{73}Ga}\rightarrow\mathrm{{}^{73}Ge}+4\mathrm{\gamma{}}+\mathrm{e}^-

However, since there is a short time delay between the beta decay and the high energy gamma emissions and the third and fourth gamma rays, it is said that the lower energy gamma rays are delayed.

Delayed gamma emissions are the most common form of delayed radiation but it is not the only form. It is common for the short-lived isotopes to have delayed emissions of various particles. In these cases it is commonly called a beta-delayed emission. This is because the decay is delayed until a beta decay takes place. For instance nitrogen-17 emits two beta-delayed neutrons after its primary beta emission. Just as in the above delayed gamma emission, the nitrogen is not the actual source of the neutrons, a short lived isotope of oxygen is.

Advanced Search
Included Web Search Engines


Safe Search

close

Top Matching Results

Occasionally Search.com will highlight specialized results that are based on the context of your query. Examples of specialized results include specific links to news, images, or video.

Top Matching Results may highlight information from other Search.com pages, content from the CNET Network of sites, or third party content. The listings are based purely on relevance. Search.com does not receive payment for listings in this section but our partners that provide this data may get paid for listing these products.

Sponsored Links

This section contains paid listings which have been purchased by companies that want to have their sites appear for specific search terms and related content. These listings are administered, sorted and maintained by a third party and are not endorsed by Search.com.

Search Results

Search.com sends your search query to several search engines at one time and integrates the results into one list which has been sorted by relevance using Search.com's proprietary algorithm. You can customize the list of search engines included in your metasearch from the preferences.

The search engines that are used in your metasearch may allow companies to pay to have their Web sites included within the results. To view the Paid Inclusion policy for a specific search engine, please visit their Web site. Search.com does not accept payment or share revenue with any search engine partner for listings in this section.