Jump to content
Sturgeon's House
Sign in to follow this  
LostCosmonaut

Too Fast to Die; Tantalum-180m

Recommended Posts

Everybody here is probably familiar with the concept of isotopes. Different atoms of the same type might have different amounts of neutrons, giving them different properties. Two of the most well known isotopes are Uranium-238 and -235, but every element has multiple isotopes. Some of these are stable, while others decay in fractions of a second.

 

Sometimes, when a particular isotope gets excited (energy added to the nucleus), it can enter a "metastable" state, where it holds on to the energy for a while instead of releasing it or decaying immediately. Most metastable isotopes decay back to their regular forms or into another atom fairly quickly, and are less stable than their parents. With one exception; Tantalum-180m.

 

Tantalum-180 has a half life of about 8 hours, decaying to hafnium or tungsten. Tantalum-180m, despite containing more energy in its nucleus, does not do this. In fact, it has never been observed to decay. It is predicted that -180m should decay, either to tantalum-180, hafnium, or tungsten, but this has not yet been seen to happen. Based on present data, Tantalum-180m has a half life of at least 1015 years, far greater than the age of the universe. It is believed that Tantalum-180m is produced in supernova explosions, but the isotopes rarity and poorly understood nature means that scientists are unsure.

 

The reason behind tantalum-180m's stability is actually the amount of energy it has. This energy is stored as angular momentum in the nucleus, and is commonly referred to as nuclear spin. Most atoms have a nuclear spin of 0 or another small value, such as 1/2 or 3/2. Tantalum-180m has 9, while Tantalum-180 has 1. This means that a very large amount of energy must be released from the -180m nuclear at once to decay (about 75 keV, corresponding to soft X-rays). Such an energy release happening all at once is extremely unlikely. As a result, Tantalum-180m is stuck in its metastable state, with too much energy to decay. It is literally too fast to die.

Share this post


Link to post
Share on other sites

I know this is a dumb question, but I'm asking it anyhow.  Is there any way to give the nucleus a poke to get it to decay?

 

Metastable isomers are just about the only possible energy storage concept I'm aware of that could give energy density between chemical and nuclear.

Share this post


Link to post
Share on other sites

Wiki says it's possible, but not really in a manner that would let you use it as an energy source; https://en.wikipedia.org/wiki/Induced_gamma_emission

Also, most of the nuclei it works with are heavily radioactive.

 

There was some guy back in the 90s who claimed he triggered energy release from hafnium-178m, but it later turned out he was full of shit.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×