Dynamics and Density Measurements in a Small Plasma Focus of Tens-of-Joules-Emitting Neutrons
Ariel Tarifeño-Saldivia · Cristian Pavez · José Moreno · Leopoldo Soto
Summary and citation · read the original at the source
In one page
A plasma focus fires a capacitor bank into two coaxial electrodes; the current sheet sweeps down the barrel, folds over the end and collapses onto the axis, squeezing a tiny knot of plasma dense and hot enough to fuse deuterium. Ariel Tarifeño-Saldivia, Cristian Pavez, José Moreno and Leopoldo Soto ran that experiment on PF-50J, a machine storing only tens of joules and driving only tens of kiloamperes, and looked inside it with interferometry — reading how much the plasma bends a laser beam to recover the electron density and the shape of the collapse, shot by shot. They tracked the radial phase, measured the conditions in the pinch itself, and recorded the neutrons from the same shots. The finding is the one that matters for anyone who wants fusion-relevant plasma on a bench: the dynamics, the pinch conditions and the electron densities that large plasma-focus machines produce are all present in a device operating at tens of joules.
Why it matters hereChapter 12 needs evidence that the plasma conditions for fusion do not require a hall-sized machine, and this is the direct density measurement that says so; chapter 9 studies self-organising, self-compressing plasma structures, and the pinch is the cleanest laboratory example of one.
What it claims
01Interferometry was used to study the dynamics of the radial phase and the plasma conditions in the pinch phase of PF-50J, a plasma focus operating in the range of tens of joules stored in the capacitor bank and tens of kiloamperes of current.Abstract, sentence 1; IEEE Transactions on Plasma Science 39, 756 (2011)
Published and peer-reviewed02The experiments used deuterium as the filling gas, and neutron production was measured simultaneously with the interferometry, so the plasma conditions and the fusion signal come from the same shots rather than from separate campaigns.Abstract, sentence 2; title
Published and peer-reviewed03The result is that the typical dynamics, the pinch conditions and the electron density observed in much larger machines are also present in a device operated at only tens of joules.Abstract, final sentence
Published and peer-reviewed04This raises the standard of evidence for the small plasma focus: the same group’s earlier work established the pinch at tens of joules from electrical signatures alone, while here the density and the collapse are measured directly by an optical method and are accompanied by neutrons.Title and abstract, read against Silva, Soto, Kies and Moreno, Plasma Sources Science and Technology 13, 329 (2004)
Published and peer-reviewed05What to watch: the scaling question this line of work opens is how neutron yield per joule behaves as the device shrinks further, and whether the emission in these very small devices is dominated by beam-target or thermonuclear processes — the measurement is a yield-and-spectrum campaign across the group’s progressively smaller machines.Abstract, final sentence; the device series described in the same authors’ subsequent work
What to watch
The way in
https://doi.org/10.1109/tps.2010.2091111SOURCE NOT REACHED IN FULL. The article is held closed by IEEE; Unpaywall and OpenAlex both report no open version, the publisher page returned nothing to an ordinary request on 2026-09-08, and the two repository records OpenAlex lists — a DSpace entry at the Universidad de Talca and a CiteSeerX summary — were unreachable the same day. So no text of the article is reproduced here, and the summary and claims are written from the authors’ own published abstract as indexed by OpenAlex and from the Crossref record: IEEE Transactions on Plasma Science, volume 39, issue 2, pages 756 to 760, February 2011. Locators therefore point to the abstract and title rather than to numbered sections. The authors work at the Comisión Chilena de Energía Nuclear in Santiago, with Pavez and Soto also associated with the Center for Research and Applications in Plasma Physics and Pulsed Power and Universidad Andres Bello; device parameters for the PF-50J family are cited on this site from the group’s own 2004 paper rather than from this one.
How to cite it
Ariel Tarifeño-Saldivia, Cristian Pavez, José Moreno, Leopoldo Soto (2011) Dynamics and Density Measurements in a Small Plasma Focus of Tens-of-Joules-Emitting Neutrons. doi:10.1109/tps.2010.2091111
Where it sits in the curriculum
Plasmoids, charge clusters and the orbsLattice confinement fusion