Historical research guide · 1012 · 1999

Foam target experiments with the PF-1000 plasma focus facility

L. Karpiński · M. Scholz · J. G. Linhart · A. Szydłowski

In one minute

A plasma focus normally makes its own target: the current sheath sweeps down a pair of coaxial electrodes, folds in on the axis and pinches the gas it is carrying. This paper asks the machine to do something else — to act as a driver, and squeeze a target somebody else put there. The target is a foam liner, a cylinder of plastic foam so light it is mostly empty space, and the machine is PF-1000 in Warsaw, one of the largest plasma-focus devices ever built. Karpiński, Scholz, Linhart and Szydłowski watched the collision with a streak camera, an instrument that trades a picture for a history by smearing one slit of the image across the film, so position and time are read off a single frame. What they report is the word that matters in any implosion: uniform. A thin foam liner can be imploded evenly by a plasma-focus current sheath, rather than being torn into fingers on the way in.

Connection

Chapter 9 treats the plasma focus as the working plasmoid machine of this whole subject, and this experiment shows it has a second job. It is not only a pinch that produces neutrons and beams; it is a megajoule driver that can compress a separately made target — which is how the plasma-focus line joins up with liner-implosion fusion rather than staying a curiosity of its own.

From the source

This was a first. The campaign is reported by the team as a foam-liner experiment performed for the first time with the PF-1000 large plasma focus facility — a use of the machine as a driver for an external target rather than as a self-contained pinch.Companion paper, Foam liner driven by a plasma focus current sheath, Physics Letters A 262, pages 453 to 456 (1999), abstract, first sentence
The measurement is optical and time-resolved. A streak camera was used to observe the interaction of a hydrogen plasma current sheath with a cylindrical foam target, which is the diagnostic that shows whether an implosion stays even or breaks up, because it records the shape of the front against time rather than a single instant.Abstract, second sentence
The result is uniformity. It is shown that a thin foam liner can be uniformly imploded by a plasma focus current sheath. Uniformity is the whole battle in any liner implosion — an implosion that goes in unevenly converts its energy into fingers and turbulence instead of compression — so this is the finding the paper exists to report.Abstract, third sentence
The physics under study was the coupling itself. The authors state that the interaction of the plasma-focus current sheath with the liner was the problem of main interest in the experiment: not how much yield came out, but whether a magnetically driven sheath can hand its momentum cleanly to a low-density solid target.Companion paper, Physics Letters A 262, page 453 (1999), abstract, second sentence
The liners were borrowed from a different fusion programme, and the aim was a new kind of driver. The foam liners were produced for the Angara liner-implosion programme at TRINITI, and the stated goal of the joint experiment was to elaborate a new method of plasma-liner production for compact implosion using a multiterawatt pulsed-power driver. What would settle that goal is a compact implosion actually driven this way, with the compression measured.Earlier report of the same collaboration, Plasma focus current shell implosion onto foam liner, DOI 10.1063/1.53882 (1997), abstract
The scale is what makes the result carry. PF-1000 at the Institute of Plasma Physics and Laser Microfusion in Warsaw is one of the largest plasma focus machines ever built, a megajoule capacitor bank discharged down a pair of coaxial electrodes — the top of a range that runs down through kilojoule and sub-kilojoule devices, all described by the same model.Review of Recent Experiments with the Megajoule PF-1000 Plasma Focus Device, on this site at /library/stm-ee0d3d807a; the range of machines the standard model covers is stated in Sing Lee’s review at /library/stm-a9cc428c6d

The way in

https://doi.org/10.1007/s100530050373

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

PUBLICATION. The European Physical Journal D, volume 7, issue 2, pages 255 to 259, dated 1 September 1999. The journal prints the authors by initial; the diacritics dropped by the Crossref deposit are restored from the OpenAlex record — Karpiński, Szydłowski. L. Karpiński and M. Scholz, the Marek Scholz who has his own page on this site, were at the Institute of Plasma Physics and Laser Microfusion in Warsaw, where PF-1000 stands; J. G. Linhart was at the University of Ferrara and A. Szydłowski at what is now the National Centre for Nuclear Research. LICENCE AND TEXT. Crossref registers only Springer’s text-and-data-mining licence, and Unpaywall and OpenAlex both report the record closed on 2026-09-08 with the only other listed location a dead SpringerLink full-text link, so nothing beyond the authors’ own abstract is reproduced here. WHAT WAS READ. The abstract below is the one the publisher deposited, retrieved on 2026-09-08 from the OpenAIRE publications API for this DOI. It runs to three sentences, so three of the claims below are located instead to the deposited abstracts of the same campaign’s two companion papers, each named in its locator: the team’s Physics Letters A report, Foam liner driven by a plasma focus current sheath, volume 262, pages 453 to 456 (1999), whose author list adds W. Stępniewski and the TRINITI group; and the earlier conference report, Plasma focus current shell implosion onto foam liner, DOI 10.1063/1.53882 (1997), which records where the foam liners came from and what the joint experiment was for. CHAPTERS. The skeleton carried none; this is a plasma focus driving a liner, so it is filed to chapter 9.

How to cite it

L. Karpiński, M. Scholz, J. G. Linhart, A. Szydłowski (1999) Foam target experiments with the PF-1000 plasma focus facility doi:10.1007/s100530050373

Where it sits in the curriculum

Fusion machines: pinches, focus devices and inertial drivers