Historical research guide · 0887 · 2018

Neutron Emission from the Plasma Focus PF-24 Device Under Different Ar Doping in Ar+D2 Mixtures — Experiments and Simulations

Łukasz Marciniak · Agnieszka Kulińska · Marek Scholz · Mohamad Akel · Sing Lee · Hans-Joachim Kunze · Sor Heoh Saw

In one minute

The PF-24 is a plasma focus at the Institute of Nuclear Physics in Kraków: a machine that dumps a capacitor bank into a gas and lets the current sheet collapse onto itself, squeezing a pencil of plasma hard enough that deuterium nuclei fuse. Łukasz Marciniak and colleagues fired it at 16.8 kilojoules and asked a direct question — what happens if you mix argon into the deuterium? Argon is heavier and radiates strongly, and there was reason to hope the extra radiation would help the column collapse harder. They ran the machine on pure deuterium, on pure argon, and on mixtures from three to sixty percent argon at constant total pressure, recording the current, its rate of change, and the neutron count on every shot. The neutron yield fell away sharply as argon went in. Every discharge was then reproduced in the Lee model code, and the computed yields matched the measured ones. A newly installed four-frame camera photographed the pinch in ultraviolet and soft X-ray light.

Connection

Chapter 9 is about self-organised plasma structures — the pinch, the plasmoid, the column that holds itself together long enough to do nuclear work — and this is one of the clean, fully instrumented tests of what makes such a structure collapse well and what spoils it, with the current trace, the neutron count and a simulation of every single shot.

From the source

A Mather-type dense plasma focus, a dynamic Z-pinch, fired at 16.8 kilojoules of stored energy in deuterium produces deuterium-deuterium fusion neutrons from a self-organised plasma pinch, measured shot by shot with a beryllium activation counter alongside a Rogowski coil and a magnetic probe.ICOPS 2018 abstract, experimental description
Neutron yield per discharge decreased rapidly as argon was added to the deuterium, across a doping range of three to sixty percent argon at constant total gas pressure. In the team’s full-length treatment of the same campaign the conclusion is stated flatly: there is no neutron yield enhancement with argon seeding, and a scaling law of neutron yield against argon fraction is deduced from it.ICOPS 2018 abstract, results; companion paper abstract, DOI 10.1109/tps.2019.2932182
Every discharge was simulated and fitted with the five-phase Lee model code, extended here to handle gas mixtures, by matching the computed total discharge current waveform to the measured one. The computed neutron yields and electro-kinetic plasma parameters agree with the measured values.ICOPS 2018 abstract, simulation section
The neutron yield in that model is computed from a plasma diode action together with a beam-target interaction mechanism — deuterons accelerated by the collapsing pinch striking the surrounding gas — rather than from a thermal plasma held at fusion temperature.ICOPS 2018 abstract, on the yield equation implemented in the code
A newly installed four-frame high-speed imaging system recorded two-dimensional cross-sections of the plasma pinch in vacuum-ultraviolet and soft X-ray light during several of the discharges, giving direct pictures of the compressed column alongside the electrical and neutron diagnostics.ICOPS 2018 abstract, stated purpose and diagnostics
The campaign behind the full-length paper ran 103 discharges — 34 in pure deuterium and 69 in deuterium with argon fractions of 3, 5, 10, 15, 22, 25, 30, 45 and 60 percent — over four sessions at a constant optimum total initial pressure of about 2.2 torr, and concludes that the PF-24 configuration is optimised for deuterium-deuterium fusion neutron emission.Companion paper abstract, DOI 10.1109/tps.2019.2932182

The way in

https://doi.org/10.1109/icops35962.2018.9575871

Historical source-access record. This guide links to the original; it does not reproduce the paper text.

A conference contribution to the 2018 IEEE International Conference on Plasma Science, ICOPS, dated 24 June 2018. The first three authors are at the Institute of Nuclear Physics of the Polish Academy of Sciences in Kraków, where the PF-24 machine stands; the others are at the Atomic Energy Commission of Syria, INTI International University and the University of Malaya, the Ruhr University Bochum, and Nilai University. LICENCE AND TEXT. The record is closed at IEEE, with no open repository copy reported by Unpaywall or OpenAlex, so this page reproduces no text. SOURCE FOR THE CLAIMS. The authors’ own deposited abstract for this DOI was recovered in full from the OpenAlex and Crossref records and read on 2026-09-08, and the claims and locators below are written from it together with the deposited abstract of the team’s full-length treatment of the same campaign, ‘Investigation of the Measured and Computed Neutron Yield From the PF-24 Device Operated With D2-x per cent Ar Admixture’, IEEE Transactions on Plasma Science, DOI 10.1109/tps.2019.2932182, which supplies the shot counts, the pressure and the conclusion on argon seeding. Neither full text was reachable; the locators say which of the two abstracts each claim rests on. The device description in the group’s open-access Nukleonika paper, DOI 10.1515/nuka-2016-0068, records that PF-24 can run to 93 kilojoules and 40 kilovolts. CHAPTERS. The skeleton carried chapter 9 and chapter 12; this is a dense plasma focus pinch rather than a loaded lattice, so it is filed to chapter 9.

How to cite it

Łukasz Marciniak, Agnieszka Kulińska, Marek Scholz, Mohamad Akel, Sing Lee, Hans-Joachim Kunze, Sor Heoh Saw (2018) Neutron Emission from the Plasma Focus PF-24 Device Under Different Ar Doping in Ar+D2 Mixtures — Experiments and Simulations doi:10.1109/icops35962.2018.9575871

Where it sits in the curriculum

Fusion machines: pinches, focus devices and inertial drivers