102. Bowden-Reid, Richard (7 June 2019). An Experimental Study of Gridded and Virtual Cathode Inertial Electrostatic Confinement Fusion Systems (Technical report). University of Sydney.In June 2019, the results of long-running experiments at the University of Sydney (USyd) were published in PhD thesis form by Richard Bowden-Reid. Using an experimental machine built at the University, the team probed the formation of the virtual electrodes.
Their work demonstrated that little or no trace of virtual electrode formation could be found. This left a mystery; both their machine and previous experiments showed clear and consistent evidence of the formation of a potential well that was trapping ions, which was previously ascribed to the formation of the electrodes. Exploring this problem, Bowden-Reid developed new field equations for the device that explained the potential well without electrode formation, and demonstrated that this matched both their results and those of previous experiments.
Further, exploring the overall mechanism of the virtual electrode concept demonstrated that its interactions with the ions and itself would make it "leak" at a furious rate. Assuming plasma densities and energies required for net energy production, it was calculated that new electrons would have to be supplied at a rate of 200,000 Amps. This is essentially unfeasible.
The paper sums up the results this way:
Initial results indicate negligible charge trapping with little to no potential well formation. Further, it is shown that the existence of potential wells reported in previous publications can be explained without the requirement of a virtual cathode produced by trapped electrons. Moreover, it is shown that potential wells, which produce electron conﬁnement and heating from virtual cathodes, no longer exist with increasing plasma density.
The results were so convincing that it has been described as a "final nail in the coffin for polywells." However, Bowden-Reid's research admitted that it had little insight into what EMC2's research and development program entailed due to the lack of published articles and intellectual property restrictions, recommended upgrades to the SDyd machine, and concluded by stating, "Continued development of MCVC-0 is required in order to properly rule out the possibility of charge induced potential well formation. Owing to the poor confinement properties of the biconic cusp when compared with the Polywell configuration, it is possible that the observed behaviour is an artefact of insufficient electron injection current... It is hoped that the above upgrades will result in a machine that is capable of generating measurable deuterium-deuterium fusion".:149
EMC2's last known publication was on the discovery of an electron gyroradius scale current layer and its relevance to magnetic fusion energy, the Earth's magnetosphere, and sunspots.
103. "Is the polywell fusion approach still under active development anywhere?". I spoke to Joe Khachan (head of the USyd lab) about the results and he described the results as a "final nail in the coffin for polywells.
104. Park, Jaeyoung; Lapenta, Giovanni; Gonzalez-Herrero, Diego; Krall, Nicholas A. (2019-12-13). "Discovery of an Electron Gyroradius Scale Current Layer: Its Relevance to Magnetic Fusion Energy, Earth's Magnetosphere, and Sunspots". Frontiers in Astronomy and Space Sciences. 6: 74. arXiv:1901.08041. Bibcode:2019FrASS...6...74P. doi:10.3389/fspas.2019.00074. ISSN 2296-987X. S2CID 119411012.