Steady-state radiation ablation in the wire-array Z pinch
Edmund P. Yu · Bryan V. Oliver · Daniel B. Sinars · Thomas A. Mehlhorn · Michael E. Cuneo · Pavel V. Sasorov · Malcolm G. Haines · Sergey V. Lebedev
Abstract and summary · read the original at the source · none found
In one page
A wire-array Z pinch begins as a cage of hair-fine wires strung around a common axis. Millions of amps are pushed through the cage, and before anything implodes each wire spends most of the shot quietly boiling: a cold dense core survives while plasma streams off it toward the axis. How fast that boiling runs — the mass ablation rate — sets what happens next. Edmund Yu and his Sandia colleagues, with Pavel Sasorov in Moscow and Malcolm Haines and Sergey Lebedev at Imperial College London, treat the boiling as a steady state and simulate it in the plane cut across the array. By naming the mechanisms that actually carry energy to the wire, they derive a simple scaling law tying the ablation rate to the drive current, for the case where radiation rather than conduction delivers the heat. They then strip the problem to an analytical model — a wire core sitting in a heat bath, ablating because it is irradiated — to find how the rate depends on core size, and put model, simulation and experiment side by side.
Why it matters hereChapter 9 is about plasma that organises itself into current-carrying structures, and the ablation phase is where a wire array decides what structure it will implode as; chapter 12 depends on the same machines, because wire arrays drive the largest laboratory X-ray sources built for fusion, and the mass ablation rate is the number every one of those designs is built on.
What it claims
01The mass ablation phase of a wire-array Z pinch can be treated as a steady state and studied that way: the paper investigates it using steady-state simulations in the (r,θ) plane, the plane cut across the array rather than along its axis.Abstract, first sentence
Published and peer-reviewed02The ablation process is governed by a small set of dominant physical mechanisms, and identifying them is what makes the problem tractable — the paper’s scaling result follows from that identification rather than from a fit to data.Abstract, second sentence
Published and peer-reviewed03A simple scaling relation is derived linking the mass ablation rate ṁ to the drive current I, for the case where radiation is the primary energy transport mechanism carrying heat to the wire core.Abstract, second sentence
Published and peer-reviewed04The dependence of the ablation rate on the size of the surviving wire core is investigated with a simplified analytical model — a wire core placed in a heat bath and ablating because it is being irradiated — rather than by simulation alone.Abstract, third sentence
Published and peer-reviewed05The three lines of evidence are put against one another: results of the model, the simulation and the experiment are compared, so the analytical scaling is tested rather than asserted.Abstract, closing sentence
Published and peer-reviewed06What to watch is the boundary of the radiation-dominated case the scaling is derived for. The measurement that would settle where it ends is an ablation-rate campaign that walks the drive current and the wire material across the point at which conduction, rather than radiation, becomes the channel carrying energy to the core, and shows whether the current scaling bends there.Abstract, second sentence, read against its own stated condition
What to watch
Read it · abstract
Abstract
The mass ablation phase of a wire-array Z pinch is investigated using steady-state (r,θ) simulations. By identifying the dominant physical mechanisms governing the ablation process, a simple scaling relation is derived for the mass ablation rate ṁ with drive current I, in the case where radiation is the primary energy transport mechanism to the wire core. In order to investigate the dependence of ṁ on wire core size, a simplified analytical model is developed involving a wire core placed in a heat bath and ablating due to radiation. Results of the model, simulation, and experiment are compared.
Edmund P. Yu, B. V. Oliver, D. B. Sinars, T. A. Mehlhorn, M. E. Cuneo, P. V. Sasorov, M. G. Haines and S. V. Lebedev, Steady-state radiation ablation in the wire-array Z pinch, Physics of Plasmas 14, 022705 (2007). The published article is at doi.org/10.1063/1.2435332.
(Abstract only, and the full article was not reachable — see the rights note above.)
On this site, the analytic model of what a whole array does once the ablated plasma has been laid down is at /library/stm-fbf26262c6; the smallest version of the same experiment, two wires and nothing else, is at /library/stm-704d7be815; what changes when the wire is aluminium rather than tungsten is at /library/stm-02af410435; and the crossed-wire X-pinch, where the ablated corona is measured directly at the point of strongest squeeze, is at /library/stm-9032278077.
The way in
https://doi.org/10.1063/1.2435332STATUS RAISED FROM SUMMARY-ONLY TO ABSTRACT-ONLY, AND WHY. The article is held closed by AIP Publishing as Physics of Plasmas volume 14, issue 2, article 022705, February 2007. Crossref carries no licence statement of any kind for this identifier, and Unpaywall and OpenAlex both report it closed with no repository copy, so no text of the paper is reproduced here. The authors’ own complete abstract, however, is carried by the AIP deposit through Crossref and independently by the United States Department of Energy at OSTI record 20976597, and the two agree word for word; that abstract is what appears below, and the summary and every claim on this page are written from it. Each locator therefore names a sentence of the abstract, because the abstract is what was read. FULL TEXT HUNTED AND NOT REACHED, 2026-09-08. The work was done at Sandia National Laboratories, so the Department of Energy catalogue was the first place looked: OSTI holds record 20976597 as a bibliographic entry with the abstract and no full-text link, and an author search across Edmund Yu’s twenty indexed Sandia records returns no report version of this paper. A phrase search of the OSTI full-text index returns nothing matching. Imperial College London’s Spiral repository, where Malcolm Haines and Sergey Lebedev deposited, does not hold it. CORE redirects without a match, and the Internet Archive’s index of the AIP article pages timed out on repeated requests. TEXT FIDELITY. The publisher’s deposit writes the mass ablation rate as the letter m carrying a combining dot above; it is rendered below with the single precomposed character ṁ, which is the same symbol, and nothing else in the abstract is altered. AUTHORS AND AFFILIATIONS as deposited: Edmund P. Yu, B. V. Oliver, D. B. Sinars, T. A. Mehlhorn and M. E. Cuneo at Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico; P. V. Sasorov at the Institute of Theoretical and Experimental Physics, Moscow; M. G. Haines and S. V. Lebedev at the Blackett Laboratory, Imperial College London. The given names of the first four Sandia authors and of the two Imperial authors are expanded here from the published initials; the byline itself gives initials.
How to cite it
Edmund P. Yu, Bryan V. Oliver, Daniel B. Sinars, Thomas A. Mehlhorn, Michael E. Cuneo, Pavel V. Sasorov, Malcolm G. Haines, Sergey V. Lebedev (2007) Steady-state radiation ablation in the wire-array Z pinch. doi:10.1063/1.2435332
Where it sits in the curriculum
Fusion machines: pinches, focus devices and inertial drivers