STM-D-1006Paper2004Published and peer-reviewed

Plasma dynamics during the evolution of two wire Z-pinch

F. N. Beg · J. Ruiz-Camacho · M. G. Haines · A. E. Dangor

Abstract and summary · read the original at the source · none found

In one page

A Z-pinch is a wire vaporised by an enormous current pulse, with the current’s own magnetic field crushing the resulting plasma inward. The big machines use arrays of hundreds of wires, and how neighbouring wires affect each other decides how the implosion goes. Beg, Ruiz-Camacho, Haines and Dangor at Imperial College strip that question to its smallest version: two parallel wires, a peak current of 160,000 amps delivered in about 65 billionths of a second, aluminium or tungsten, at three different spacings. What they report is that two wires do not simply become two plasmas. A third plasma column appears in the gap between them, well before the wires themselves implode, and the vapour boiling off each wire expands lopsidedly rather than in a neat cylinder. All three plasmas go unstable, in different ways: the wires develop sausage-like necking, in step with one another, while the central column kinks sideways in the plane that contains both wires. That middle instability tells the authors current has moved off the wires into the plasma they made.

Why it matters hereChapter 9 follows plasma that organises itself into structures that hold together and carry current, and this is the smallest clean laboratory case of it: two current-carrying filaments spontaneously build a third column between them and hand it part of their current. It is also the physics that governs every wire-array driver used for pinch fusion, so it sits directly upstream of the machines chapter 12 depends on.

What it claims

01Two parallel wires driven together do not stay two plasmas. Besides the plasma at each wire and its surrounding corona, a distinct plasma column forms centred in the gap between the wires, and it forms well before the wires themselves implode.Abstract
Published and peer-reviewed
02The corona around each wire expands asymmetrically rather than in a cylindrically symmetric shell, so the presence of the neighbouring wire shapes the ablation flow from the start.Abstract
Published and peer-reviewed
03All three plasmas become unstable, and the mode depends on which plasma it is: the wire plasmas show the characteristic m equals zero sausage perturbation, while the central column shows predominantly the m equals one kink.Abstract
Published and peer-reviewed
04The instabilities are organised by the geometry rather than random: the m equals zero perturbations on the two wires are spatially correlated with each other, and the m equals one perturbations of the central plasma develop in the plane that contains the two wires.Abstract
Published and peer-reviewed
05The growth of instability in the central column implies that some of the current has transferred from the wires into that column, so the plasma the wires create takes over part of the drive current before implosion.Abstract
Published and peer-reviewed
06The experiment is run at a scale where the geometry can be varied deliberately: a pulsed-power source of 160 kiloamps peak with a 65 nanosecond rise time from 10 to 90 percent, aluminium wires of 15 micrometres and tungsten wires of 7.5 micrometres, at wire separations of 0.3, 0.6 and 1.5 millimetres.Abstract
Published and peer-reviewed

Read it · abstract

Abstract

Experiments on a two parallel wire Z-pinch are reported. The pinch was driven by a 160 kA peak current, 65 ns 10–90% rise time pulsed power source. Aluminium (15 µm) and tungsten (7.5 µm) wires with varying separations (0.3, 0.6 and 1.5 mm) were used. In addition to the plasma at each wire and its associated corona, a plasma column centred between the wires is formed, well before implosion of the wires. The expansion of the coronal plasma around each wire is asymmetric. Both the wire plasmas and the central plasma develop instabilities — characteristic m = 0 in the wire plasmas and predominantly m = 1 in the central plasma; the m = 0 perturbations in the wires are spatially correlated; the m = 1 perturbations in the central plasma are in the plane containing the wires. The development of instability in the central plasma implies a transfer of some current from the wires to the central plasma.

F. N. Beg, J. Ruiz-Camacho, M. G. Haines and A. E. Dangor, Plasma dynamics during the evolution of two wire Z-pinch, Plasma Physics and Controlled Fusion 46, 1 (2004), published online 27 November 2003, from the Plasma Physics Group of the Blackett Laboratory, Imperial College London.

(Abstract only, and the full text was not reachable — see the rights note above. On this site, the same laboratory’s wire-array implosion experiments are at /library/stm-33d8266a67, what the discreteness of the wires does to an implosion is at /library/stm-bb03ac17ef, the steady-state ablation that feeds the corona is at /library/stm-a2345abd6a, Sandia’s microfabricated arrays built to control exactly this geometry are at /library/stm-98d874080d, and the same group’s prepulse experiment on a fibre Z-pinch is at /library/stm-06c1a40035.)

The way in

https://doi.org/10.1088/0741-3335/46/1/001SOURCE NOT REACHED IN FULL. The article is held by IOP Publishing as Plasma Physics and Controlled Fusion volume 46, issue 1, pages 1 to 10, and its full text is closed to automated retrieval: the publisher’s own PDF address, which Unpaywall and OpenAlex both list as the only open location and label bronze, returns the publisher’s bot page rather than the file. Checked on 2026-09-08 against Crossref, OpenAlex, Unpaywall, OpenAIRE, Semantic Scholar, CORE and the Imperial College Spiral repository, none of which holds a repository copy or an author preprint, and the authors posted none to arXiv. No text of the paper beyond the abstract is reproduced here, and the summary and the claims below are written from the authors’ own complete abstract together with the bibliographic record; every locator therefore says Abstract, because the abstract is what was read. YEAR. The registry record carried 2003, the date the article appeared online, 27 November 2003; the issue itself is dated January 2004 and the paper is cited as volume 46, page 1, 2004, which is the year given here. AUTHORS. Initials are left unexpanded because no publisher record consulted gives the authors’ given names. The work is from the Plasma Physics Group of the Blackett Laboratory at Imperial College London.

How to cite it

F. N. Beg, J. Ruiz-Camacho, M. G. Haines, A. E. Dangor (2004) Plasma dynamics during the evolution of two wire Z-pinch. doi:10.1088/0741-3335/46/1/001

Where it sits in the curriculum

Plasmoids, charge clusters and the orbs