Induced Gamma Emission
There's research ongoing into a relatively unknown form of nuclear power, called "Induced Gamma Emission" (IGE). There are rumors/innuendo that research potentially could be towards a new form of fusion bomb, or a new radiological weapon. It also might create the world's best battery.
Induced Gamma Emission first forces nuclei into an excited state via very precisely tuned photon projectiles. Falling back to ground state releases the nuclei' extra energy in the form of gamma rays and X-rays. It resembles electrical emission in higher-energy electron orbitals, but it's in the nucleus, involving the residual strong force.
If the higher energy state is stable, and requires a second photon to go to ground, this makes the nucleus like a rechargeable battery.
But these dual-state-stable isotopes are very rare. There are very rare isotopes that are known as "metastable isotopes". Metastable isotopes' nuclei are stuck in a higher-energy state than they might otherwise be in. It's possible on a handful of metastable isotopes to excite the "stuck" stable state into an even higher unstable state, which then falls to the lowest stable energy state. So it pumps out more energy than it receives.
Then with a few, you can then "pump" the atom back up to the original metastable isotope state. And thereby create, in essence, a very-high-capacity rechargeable battery.
The list of promising, "safe" metastable isotopes that do not involve cycles with isotopes that decay quickly is tantalum-180m, osmium-187m, platinum-186m, hafnium-178m2 and zinc-66m. Only the tantalum occurs naturally.
Much like fusion and fission, the energies involved are enormous. For fission of U-235, it's 202.5 MeV per atom, for fission of Pu-239, it's 207.1 MeV/atom, for fusion of deuterium-tritium fuel, it's 17.6 MeV/fusion, and for Hf-178-m2, it's ~2.4MeV per IGE.
If this can be "tamed" and engineered, there are several readily apparent potential applications:
1) Most obviously, this is a gamma ray emitter, and a highly tunable one at that. Gamma rays have many potential medical uses (CT scans, radiation therapy) and security uses (performing gamma ray scans).
2) Tantalizingly, this might lead to an extremely high energy-density battery, if the right isotopes are found, and the right engineering environment for cycling the isotopes is made.
3) If one can cause a large mass of metastable isotopes to emit at once, a huge amount of energy would result. One potential use of this is compressing fusion fuel, and thus creating a fusion bomb explosion.
4) Similarly, if you just had a large mass of IGE go off all at once, you'd have a potent radiological bomb, akin to a neutron bomb.
#3, using it as a fusion trigger, is very worrying, because it's not covered by the Nuclear Non-Proliferation Treaty. Worse, the controls on nuclear proliferation all involve the fission component. IGE would remove that.
It's unclear to me, as a layman, how truly effective and engineerable any of this is. There is a lot of controversy swirling around IGE, thanks to it scary weapons implications. One of the most non-neutral Wikipedia articles I've seen, weird politicized statements from scientists, and the involvement of DARPA, don't help me gain clarity on the prospects.
By the way, the metastable isotope of tantalum is literally the rarest naturally-occurring isotope in the Universe. And the ore in which we find it on Earth, coltan, is ripping apart areas of Central Africa.
Induced Gamma Emission first forces nuclei into an excited state via very precisely tuned photon projectiles. Falling back to ground state releases the nuclei' extra energy in the form of gamma rays and X-rays. It resembles electrical emission in higher-energy electron orbitals, but it's in the nucleus, involving the residual strong force.
If the higher energy state is stable, and requires a second photon to go to ground, this makes the nucleus like a rechargeable battery.
But these dual-state-stable isotopes are very rare. There are very rare isotopes that are known as "metastable isotopes". Metastable isotopes' nuclei are stuck in a higher-energy state than they might otherwise be in. It's possible on a handful of metastable isotopes to excite the "stuck" stable state into an even higher unstable state, which then falls to the lowest stable energy state. So it pumps out more energy than it receives.
Then with a few, you can then "pump" the atom back up to the original metastable isotope state. And thereby create, in essence, a very-high-capacity rechargeable battery.
The list of promising, "safe" metastable isotopes that do not involve cycles with isotopes that decay quickly is tantalum-180m, osmium-187m, platinum-186m, hafnium-178m2 and zinc-66m. Only the tantalum occurs naturally.
Much like fusion and fission, the energies involved are enormous. For fission of U-235, it's 202.5 MeV per atom, for fission of Pu-239, it's 207.1 MeV/atom, for fusion of deuterium-tritium fuel, it's 17.6 MeV/fusion, and for Hf-178-m2, it's ~2.4MeV per IGE.
If this can be "tamed" and engineered, there are several readily apparent potential applications:
1) Most obviously, this is a gamma ray emitter, and a highly tunable one at that. Gamma rays have many potential medical uses (CT scans, radiation therapy) and security uses (performing gamma ray scans).
2) Tantalizingly, this might lead to an extremely high energy-density battery, if the right isotopes are found, and the right engineering environment for cycling the isotopes is made.
3) If one can cause a large mass of metastable isotopes to emit at once, a huge amount of energy would result. One potential use of this is compressing fusion fuel, and thus creating a fusion bomb explosion.
4) Similarly, if you just had a large mass of IGE go off all at once, you'd have a potent radiological bomb, akin to a neutron bomb.
#3, using it as a fusion trigger, is very worrying, because it's not covered by the Nuclear Non-Proliferation Treaty. Worse, the controls on nuclear proliferation all involve the fission component. IGE would remove that.
It's unclear to me, as a layman, how truly effective and engineerable any of this is. There is a lot of controversy swirling around IGE, thanks to it scary weapons implications. One of the most non-neutral Wikipedia articles I've seen, weird politicized statements from scientists, and the involvement of DARPA, don't help me gain clarity on the prospects.
By the way, the metastable isotope of tantalum is literally the rarest naturally-occurring isotope in the Universe. And the ore in which we find it on Earth, coltan, is ripping apart areas of Central Africa.