 Bussard calculated that a polywell reactor with a radius of 1.5 meters would produce net power fusing deuterium.Other studies disproved some of the assumptions made by Rider and Nevins, arguing the real fusion rate and the associated recirculating power (needed to overcome the thermalizing effect and sustain the non-Maxwellian ion profile) could be estimated only with a self-consistent collisional treatment of the ion distribution function, lacking in Rider's work.It has been proposed that energy may be extracted from polywells using heat capture or, in the case of aneutronic fusion like D-3He or "p"-11B, direct energy conversion, though that scheme faces challenges.