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I was reading this post from this website:

Turning Jupiter into a star

It basically talks about whether fusion can or does happen in the core of Jupiter. I know Jupiter cannot become a star, but I started to wonder if Jupiter is capable of sustaining some constant low levels of fusion. I then started to wonder if a reactor could be constructed to mimic such conditions.

Any answers/opinions to any/all the following questions are welcomed. My questions may be redundant only because I’m attempting to understand fusion from as many perspectives as possible.

1) Assuming there is a perfect mixture of Deuterium and Tritium in the core of Jupiter, would it be possible to achieve some low level of sustaining fusion, considering the core is only about 30,000 C?

2) Fusion requires millions of degrees to ignite. Are there any other criteria that can be met (density, element percent content, pressure, etc) that can drastically lower the temperature needed?

3) If I were to create a small scale of Jupiter in a lab, where its core was the size of a basketball and there were ideal concentrations of Deuterium and Tritium and all other conditions were identical, would some level of fusion occur? If not, what would need to change? Would I have to apply more pressure on the core (and how much)? Would I have to raise the temperature (and how much)?

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  • $\begingroup$ This is a neat question but it's awfully broad. I'd suggest tackling just the "does any fusion at all take place inside of Jupiter?" first and then in another question tackle the others. $\endgroup$ – Brandon Enright Nov 2 '14 at 8:29
  • $\begingroup$ Tritium has a 12.3 years of half-life. 100% tritium-oxide ("very heavy water") warms some 10-20 degree per minute because of its own radiation. A jupiter-sized tritium-deuterium mixture "planet" heated in same days to around some 100000K, and evaporated. It would be practically a little supernova. $\endgroup$ – peterh Nov 2 '14 at 18:17
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I will answer 3) as seen in this encyclopedic entry:

Practical efforts to harness fusion energy involve two basic approaches to containing a high-temperature plasma of elements that undergo nuclear fusion reactions: magnetic confinement and inertial confinement. A much less likely but nevertheless interesting approach is based on fusion catalyzed by muons; research on this topic is of intrinsic interest in nuclear physics.

In a star, the plasma confinement is provided by gravity and the enormous pressures it generates. In the lab they mimic that by what the above quote calls "inertial confinement".

Inertial confinement fusion (ICF) is a type of fusion energy research that attempts to initiate nuclear fusion reactions by heating and compressing a fuel target, typically in the form of a pellet that most often contains a mixture of deuterium and tritium.

To compress and heat the fuel, energy is delivered to the outer layer of the target using high-energy beams of laser light, electrons or ions, although for a variety of reasons, almost all ICF devices to date have used lasers. The heated outer layer explodes outward, producing a reaction force against the remainder of the target, accelerating it inwards, compressing the target. This process is designed to create shock waves that travel inward through the target. A sufficiently powerful set of shock waves can compress and heat the fuel at the center so much that fusion reactions occur.

This last link describes the history of the various projects. As with all controlled fusion attempts it is the failure to break even and give more energy than that needed to generate the initial fusion, that keeps progress in this direction.

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