David Kirtley

We are not limited now to having a very skinny top.

We can actually make it much bigger.

So the good analogy here is if you have a coin and you know you're spinning that coin, if you spin it faster and faster, it'll stay spinning longer.

However, eventually it'll slow down and fall over.

But if you had a roll of duct tape, if you had something thicker and heavier and longer...

and it's spinning around that same axis, it'll stay spinning even longer, both because of the inertia and because of the geometry.

And so we have this parameter called S star over E. S star is the hybrid kinetic parameter, which tells you how stable it is from that top point of view, and the E, which is the elongation of how long it is.

And so maybe fortuitously, thank you nature, gave us a win here, which is that how we make these in these long solenoids is naturally very, very long.

And so we can build these with very long lengths.

And if we can drive them fast enough and hard enough and drive the ions

to move at very high velocities, we can stabilize against those instabilities and hold them stable.

And so we now know we can design with a given S star over E parameter, we can design these for very long lives.

The theory of the systems we make say that they should last for a few microseconds at most.

us and others in the field have been able to make them last for thousands of microseconds, thousands of times what the stability, the basic criteria would tell you.

And so we know now how to do this.

And so we just designed them with this built into them.

It's a great question.

So it is a requirement of the system is that you must design it with this parameter in mind.

The hard part is you have to design it with S star over E being satisfied the whole time.

And here's the extra trick here.