So a twice larger device on half pressure would have a similar discharge. One can even make a nice glow discharge even on atmospheric pressures that's several mm long if you can choose the right series resistance.

So if you

**keep the voltage constant and the product pd constant**in a fusor. How does other numbers change?

Is there a

**sweet spot in size**that maximizes the efficiency for a given input power?

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While I did my 45 minute walk into work I thought about this.

So if you build a 2 times larger device you'll have 8 times larger volume 2 times smaller pressure and density, thus 4 (=8/2) times more particles.

Due to the smaller number density, collisions 2 times less likely, thus 2 times less chance for fusion, but there are 4 times more particles, so I'd expect 2 (=4/2) times more fusion. Since there are 4 times more particles the electric field is potentially moving 4 times more charge carriers so the current is 4 times higher. 4 times more power consumption (since we assumed voltage is constant) for 2 times more gains, 2 times worse. So this would suggest that a tiny device would be better...

But I don't want to go too far, as my train of thought could be downright wrong... I'm curious what are your thoughts on this.