The polywell is an interesting concept, but it is extremely different from every other confinement mechanism, so it&#x27;s hard to see how the ideas could be incorporated. To be precise, there are two &quot;shapes&quot; of &quot;electromagnetic fields&quot;: curl-free (electric (unless magnetic monopoles exist)) and divergence-free (magnetic or electric), and each kind of field lends itself to a different kind of degree of symmetry in a confinement mechanism. Specifically, a divergence-free field cannot admit a spherical confinement because of Green&#x27;s theorem, whereas a curl-free field requires a very unrealistic charge configuration to generate a toroidal confinement.<p>Tokamaks use a combination of divergence-free magnetic fields and divergence-free electric fields to make a donut. Stellarators use only magnetic fields to make a twisted donut. The polywell uses curl-free electric fields generated by an electron gun to make a sphere. There are other variants of inertial electrostatic confinement fusion, including that currently under development by Lockheed Martin, but it&#x27;s generally received less attention.