Study on discharge plasma in a cylindrical inertial electrostatic confinement fusion device
N. Buzarbaruah · N.J. Dutta · D. Borgohain · S.R. Mohanty · H. Bailung
Abstract and summary · read the original at the source · none found
In one page
A cylindrical inertial electrostatic confinement device is about the simplest fusion machine anyone builds: a vacuum chamber holding a little deuterium, with a see-through cylindrical wire cage down the middle held at a large negative voltage. Ions formed in the gas fall towards the cage, shoot through the gaps, and keep recirculating through the centre. Buzarbaruah, Dutta, Borgohain, Mohanty and Bailung ran their machine two ways — with a heated filament supplying electrons, and without one — and read the plasma with an electrostatic probe. The two modes trade against each other. The cold-cathode discharge makes the hotter plasma, about ten electron volts; the hot-cathode discharge makes a cooler one, about three electron volts, but two orders of magnitude denser. The same probe caught something the device does on its own: ions sloshing back and forth in the negative potential well that forms between the cage and the chamber wall, oscillating spontaneously, and doing so at harmonics of the fundamental as well.
Why it matters hereChapter 9 is about plasma that organises itself — and here a benchtop machine with one voltage knob produces a potential well that rings on its own, harmonics included. Chapter 12 keeps the ledger of fusion routes, and this is the measurement that tells a builder which discharge mode buys density and which buys temperature in the cheapest confinement geometry there is.
What it claims
01Deuterium plasma was produced in a cylindrical inertial electrostatic confinement fusion device in two distinct ways — a hot cathode discharge and a cold cathode discharge — and the plasma parameters of each were determined with an electrostatic probe.Abstract, sentence 1; Physics Letters A 381, 2391 (2017)
Published and peer-reviewed02At optimum experimental conditions the plasma temperature is about 3 electron volts in the hot cathode discharge and about 10 electron volts in the cold cathode discharge, so the mode that needs no filament is the one that makes the hotter plasma.Abstract, sentence 2
Published and peer-reviewed03The trade runs the other way for density: the plasma density measured in the hot cathode discharge is two orders of magnitude greater than in the cold cathode discharge, which is the figure of merit that matters for reaction rate in a device of this kind.Abstract, sentence 3
Published and peer-reviewed04A negative potential well forms in the space between the cathode grid and the chamber wall acting as anode, and the probe was used to observe ions oscillating inside that well — the recirculating motion that defines the inertial electrostatic concept, seen directly rather than inferred.Abstract, sentence 4
Published and peer-reviewed05The oscillation is spontaneous rather than driven, and it appears together with its harmonics, so the discharge is self-organising a resonance and not merely following the applied voltage.Abstract, final sentence
Published and peer-reviewed06What to watch: the same group later modelled this machine particle by particle and matched the probe measurements, finding a core ion density around ten to the sixteenth per cubic metre, a virtual anode built from trapped ion charge, and grid transparency as the design parameter that sets core density — so the open question this paper leaves, which discharge mode and which grid geometry give the best neutron yield per watt, now has a validated simulation to answer it.Read against the same group’s Physical Review E 102, 063205 (2020), held on this site at stm-0b806244cb
What to watch
Read it · abstract
Abstract
Deuterium plasma has been produced in a cylindrical inertial electrostatic confinement fusion device using hot and cold cathode discharges and the plasma parameters are determined by employing an electrostatic probe. The plasma temperature and density are estimated at optimum experimental conditions and it is noted that the plasma temperature is 3 eV in the case of hot cathode discharge whereas 10 eV in the case of the cold cathode discharge. The plasma density as determined is two orders more in the case of the hot cathode discharge than the other. The probe is also used to observe the ion oscillation in the negative potential well that is formed in between the cathode grid and chamber (anode). The observation of spontaneous oscillation along with the harmonics has been reported.
N. Buzarbaruah, N. J. Dutta, D. Borgohain, S. R. Mohanty and H. Bailung, Study on discharge plasma in a cylindrical inertial electrostatic confinement fusion device, Physics Letters A 381, issue 30, pages 2391 to 2396, August 2017. The published article is at doi.org/10.1016/j.physleta.2017.05.029.
(Abstract only — no other text of the article is reproduced here; see the rights note above. On this site, the same group’s particle-in-cell study of this machine is at /library/stm-0b806244cb, space-charge neutralisation in inertial electrostatic plasmas is at /library/stm-5c07c85688, deuterium anions in these devices are at /library/stm-27b0684846, the neutron production rate of spherically convergent beam fusion is at /library/stm-e386fdbf31, the Defense Intelligence Reference Document on the approach is at /library/stm-cac9786426, and Philo Farnsworth’s founding patent is at /library/stm-3a226d4c01.)
The way in
https://doi.org/10.1016/j.physleta.2017.05.029SOURCE NOT REACHED IN FULL. The article is held closed by Elsevier; Unpaywall and OpenAlex both report no open version on 2026-09-08, and a search of arXiv by title and by author on the same day surfaced only this group’s later particle-in-cell paper, not this one. What is reproduced below is the authors’ own abstract exactly as the publisher deposited it, carried independently by OpenAIRE and by colab.ws; the bibliographic record is Crossref’s — Physics Letters A volume 381, issue 30, pages 2391 to 2396, August 2017. Locators therefore point to sentences of the abstract rather than to numbered sections, and no other text of the article is reproduced. The device and the group are the ones described in the companion study this site holds at stm-0b806244cb, the Centre of Plasma Physics in Assam.
How to cite it
N. Buzarbaruah, N.J. Dutta, D. Borgohain, S.R. Mohanty, H. Bailung (2017) Study on discharge plasma in a cylindrical inertial electrostatic confinement fusion device. doi:10.1016/j.physleta.2017.05.029
Where it sits in the curriculum
Plasmoids, charge clusters and the orbsLattice confinement fusion