The relationship between exploding wire expansion rates and wire material properties near the boiling temperature

Chandler, K. M.; Hammer, D. A.; Sinars, Daniel Brian; Pikuz, S. A.; Shelkovenko, T. A.

doi:10.1109/tps.2002.1024292

Cited by 50 publications

(24 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3. This value compares well with previous measurements of the velocity of expansion of Al wires of similar diameter obtained with hard X-ray radiographs and 532 nm shadowgraphy techniques [16,21]. During the onset of the recorded expansion, the central part of the vaporized wire, which contains a large density of neutral and singly ionized atoms that can be photo-ionized by the 26.5 eV photons of the probe laser, completely absorbs the probe beam.…”

supporting

confidence: 89%

“…1b. The different phases of the wire explosion as it is heated have been previously studied in correlation to the variations in the current and voltage pulses [15,16]. As the wire is heated its resistance increases, causing a drop in the rate of current increase.…”

Section: Methodsmentioning

confidence: 99%

“…Maximization of the X-ray yield requires an understanding of all phases of the plasma. The new success at Sandia National Laboratories Z-machine in the production of thermonuclear neutrons [11] driven by such X-ray burst further encourages the study of thin wire explosions.Several recent studies of the dynamics of single wire explosions conducted utilizing hard X-ray shadowgraphy and optical laser techniques [13][14][15][16][17][18][19][20][21][22] have significantly increased the understanding of single wire explosions. The probing of exploding wire plasmas with soft X-ray lasers can potentially provide complementary information on the initial stages of the explosion, where the density is high.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Soft X-ray laser diagnostics of exploding aluminum wire plasmas

Hammarsten

Szapiro

Jankowska

et al. 2004

Applied Physics B: Lasers and Optics

View full text Add to dashboard Cite

The evolution of current-driven thin single Al wire plasmas was studied with soft X-ray shadowgraphy and interferometry using a very compact capillary discharge-driven λ = 46.9 nm laser probe. Wires of 25 µm diameter excited by current pulses with a 78 A/ns increase rate were observed to expand uniformly at a rate of 3.5 µm/ns. In contrast, an increase in the rate of energy deposited per unit mass was observed to give rise to significant early plasma instabilities. The results illustrate the use of table-top soft X-ray lasers as a new tool for the diagnostics of dense pulse power driven plasmas.PACS 52.70.Kz; 52.59.Qy; 52.25.Vy; 52.50.Nr IntroductionInterferometry with optical lasers has been used for decades to obtain multi-dimensional maps of the electron density in a large variety of plasmas [1]. However, free-free absorption and refraction of the probe beam limit the maximum electron density, plasma size, and plasma density gradient that can be probed [2]. More recently, laboratory-size soft X-ray lasers have been used to extend the limits of plasma interferometry to larger plasma-scale lengths and higher plasma densities. A 15.5 nm Ne-like Y laser pumped by the Nova laser has successfully probed dense laser-created plasmas produced at Lawrence Livermore National Laboratory [2]. Due to limitations in the repetition rate of the X-ray laser, the experiments were limited to a few shots per day [2,3]. Recently, the use of compact saturated soft X-ray lasers [4][5][6] and the development of more robust interferometers [7] have advanced soft X-ray laser diagnostics as a practical tool for the study of high density plasmas [4][5][6][7]. Results of the study of the dynamics of several different laser-created plasmas have been recently reported [5][6][7]. Extremely compact capillary discharge soft-X-ray lasers [8,9], which are portable and have spectral brightness similar to or higher than that of their laboratory-size predecessors, produce laser pulses of about 1 ns duration that are particularly well suited for the diagnostics of dense pulse-power driven plasmas. Herein we report the results of the study of the evolution of current-induced u Fax: +1-970/491-8671, E-mail: rocca@engr.colostate.edu explosions of thin wires using a capillary discharge 46.9 nm laser in combination with a Mach-Zehnder interferometer in which diffraction gratings are used as beam splitters.The dynamics of thin exploding metal wire plasmas is of significant interest for the efficient generation of incoherent X-ray pulses of extremely high energy [10][11][12]. Fast Z-pinch implosions of cylindrical wire arrays have been shown to generate high energy density plasmas that emit very intense bursts of incoherent X-ray radiation capable of driving inertial confinement fusion targets [11]. In those experiments the main implosion phase, driven by multi-mega ampere currents, is preceded by a phase in which the heating, vaporization, and ionization of the wires in the array causes an expansion and merging of the individual plasmas into a co...

show abstract

supporting

confidence: 89%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Soft X-ray laser diagnostics of exploding aluminum wire plasmas

Hammarsten

Szapiro

Jankowska

et al. 2004

Applied Physics B: Lasers and Optics

View full text Add to dashboard Cite

show abstract

“…1. Since copper has been often used in the experiments such as exploding wires (3) (4) and fiber pinches, it is easy to discuss the discharge characteristics of copper. The particles are spherical and their diameters are almost the same.…”

Section: Methodsmentioning

confidence: 99%

Early Stage of Pulsed High Current Discharge with Copper Powder

et al. 2004

View full text Add to dashboard Cite

Early phase of powder plasmas powered by a pulsed high current discharge was examined by use of high-speed cameras and a laser shadowgraph and schlieren techniques. Initial electrons created by a pre-ionization discharge collide with both an anode and powder particles, of which surfaces evaporate after then. Evaporation of the particle by electron collision initially occured in the hemisphere surface which is close to cathode side. Since vaporization of the anode far exceeds that of the particles, discharge characteristics is almost similar to that of vacuum sparks in which expanding anode plasmas are observed. In order to suppress the developpment of the anode plasma, reduction of the effective anode area by varying the anode shape was examined.

show abstract

“…The plasma is highly conductive and carries the bulk of the current for the remainder of the pulse. This model has been proposed and studied by various groups over the years, and provides a good qualitative picture of the breakdown process [6,7,8,9,10]. The details of this model, including various subtleties due to different wire materials, contaminants, and current drive (initial energy deposition in the wire) make this a complex problem still under investigation [11].…”

Section: Modelmentioning

confidence: 99%

Volumetric plasma source development and characterization.

Crain

Maron

Oliver

et al. 2008

View full text Add to dashboard Cite

The development of plasma sources with densities and temperatures in the 10 15 -10 17 cm -3 and 1-10eV ranges which are slowly varying over several hundreds of nanoseconds within several cubic centimeter volumes is of interest for applications such as intense electron beam focusing as part of the x-ray radiography program. In particular, theoretical work [1,2] suggests that replacing neutral gas in electron beam focusing cells with highly conductive, pre-ionized plasma increases the time-averaged e-beam intensity on target, resulting in brighter x-ray sources. This LDRD project was an attempt to generate such a plasma source from fine metal wires. A high voltage (20-60kV), high current (12-45kA) capacitive discharge was sent through a 100μm diameter aluminum wire forming a plasma. The plasma's expansion was measured in time and space using spectroscopic techniques. Lineshapes and intensities from various plasma species were used to determine electron and ion densities and temperatures. Electron densities from the mid-10 15 to mid-10 16 cm -3 were generated with corresponding electron temperatures of between 1 and 10eV. These parameters were measured at distances of up to 1.85 cm from the wire surface at times in excess of 1μs from the initial wire breakdown event. In addition, a hydrocarbon plasma from surface contaminants on the wire was also measured. Control of these contaminants by judicious choice of wire material, size, and/or surface coating allows for the ability to generate plasmas with similar density and temperature to those given above, but with lower atomic masses.

show abstract

The relationship between exploding wire expansion rates and wire material properties near the boiling temperature

Cited by 50 publications

References 18 publications

Soft X-ray laser diagnostics of exploding aluminum wire plasmas

Soft X-ray laser diagnostics of exploding aluminum wire plasmas

Early Stage of Pulsed High Current Discharge with Copper Powder

Volumetric plasma source development and characterization.

Contact Info

Product

Resources

About