Charge resolved electrostatic diagnostic of colliding copper laser plasma plumes

Yeates, P.D.; Fallon, C.; Kennedy, E. T.; Costello, J. T.

doi:10.1063/1.3633486

Cited by 28 publications

(20 citation statements)

References 86 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Related studies include counter-streaming laser-produced plasmas supporting hohlraum design for indirect-drive inertial confinement fusion [17][18][19] and for studying astrophysically relevant shocks, [20][21][22][23][24] colliding plasmas using wire-array Z pinches, 25,26 and applications such as pulsed laser deposition 27 and laser-induced breakdown spectroscopy. 28 Primary issues of interest in these studies include the identification of shock formation, the formation of a stagnation layer [29][30][31] between colliding plasmas, and the possible role of two-fluid and kinetic effects on plasma interpenetration. [32][33][34][35] In this paper we present detailed measurements of the stagnation layer that forms between two obliquely merging supersonic plasma jets in a semi-to fully collisional a) Electronic mail: emerritt@lanl.gov b) Electronic mail: scotthsu@lanl.gov regime.…”

Section: Introductionmentioning

confidence: 99%

Experimental evidence for collisional shock formation via two obliquely merging supersonic plasma jets

et al. 2014

View full text Add to dashboard Cite

We report spatially resolved measurements of the oblique merging of two supersonic laboratory plasma jets. The jets are formed and launched by pulsed-power-driven railguns using injected argon, and have electron density ∼ 10 14 cm −3 , electron temperature ≈ 1.4 eV, ionization fraction near unity, and velocity ≈ 40 km/s just prior to merging. The jet merging produces a few-cm-thick stagnation layer, as observed in both fastframing camera images and multi-chord interferometer data, consistent with collisional shock formation [E. C. Merritt et al., Phys. Rev. Lett. 111, 085003 (2013)].

show abstract

Section: Introductionmentioning

confidence: 99%

Experimental evidence for collisional shock formation via two obliquely merging supersonic plasma jets

et al. 2014

View full text Add to dashboard Cite

show abstract

“…23 Briefly, laser plasmas were reproducibly created with Nd:yttrium aluminium garnet (Nd:YAG) Q-switched laser pulses (k ¼ 1.06 lm, s ¼ 6 ns, and E L ¼ 50-500 mJ). Focused beams were achieved with the aid of a 28 cm focal length convex-planar lens.…”

Section: Methodsmentioning

confidence: 99%

“…[17][18][19][20][21][22] Only a small number of studies of colliding laser plasma plumes have been performed with the aid of electrostatic diagnostics. [23][24][25] In previous work, 23 we used a retarding field analyzer (RFA) to carry out measurements on colliding Cu plumes as a function of laser fluence. Charge yields, time dependent current traces, and kinetic energy measurements of Cu þ to Cu 5þ ions revealed interesting results in comparison to those from a single seed plasma.…”

Section: Introductionmentioning

confidence: 99%

Atomic mass dependent electrostatic diagnostics of colliding laser plasma plumes

Yeates¹,

Fallon²,

Kennedy³

et al. 2013

Physics of Plasmas

Self Cite

View full text Add to dashboard Cite

The behaviours of colliding laser plasma plumes (C p ) compared with single plasma plumes (S p ) are investigated for 14 different atomic mass targets. A Faraday cup, situated at the end of a drift tube (L ¼ 0.99 m), is employed to record the time-of-flight (TOF) current traces for all elements and both plume configurations, for a fixed laser intensity of I p ¼ 4.2 Â 10 10 W cm À2 (F ¼ 0.25 kJ cm À2 ). The ratio of the peak current from the C p relative to twice that from the S p is designated as the peak current ratio while the ratio of the integrated charge yield from the C p relative to twice that from the S p is designated as the charge yield ratio. Variation of the position of the Faraday cup within the drift tube (L ¼ 0.33, 0.55, and 0.99 m) in conjunction with a lower laser fluence (F ¼ 0.14 kJ cm À2 ) facilitated direct comparison of the changing TOF traces from both plasma configurations for the five lightest elements studied (C, Al, Si, Ti, and Mn). The results are discussed in the frame of laser plasma hydrodynamic modelling to approximate the critical recombination distance L CR . The dynamics of colliding laser plasma plumes and the atomic mass dependence trends observed are presented and discussed. V C 2013 AIP Publishing LLC.

show abstract

“…Physics issues arising in these studies include plasma interpenetration [11][12][13][14][15][16], shock formation [17], and the formation and dynamics of a stagnation layer [18][19][20]. In this work, we present experimental results on two obliquely merging supersonic plasma jets, which are in a different and more collisional parameter regime than many of the colliding plasma examples mentioned above.…”

mentioning

confidence: 92%

Experimental Characterization of the Stagnation Layer between Two Obliquely Merging Supersonic Plasma Jets

Merritt

Hsu

et al. 2013

Phys. Rev. Lett.

View full text Add to dashboard Cite

We present spatially resolved measurements characterizing the stagnation layer between two obliquely merging supersonic plasma jets. Intra-jet collisionality is very high (λii ≪ 1 mm), but the inter-jet ion-ion mean free paths are on the same order as the stagnation layer thickness (a few cm). Fast-framing camera images show a double-peaked emission profile transverse to the stagnation layer, with the central emission dip consistent with a density dip observed in the interferometer data. We demonstrate that our observations are consistent with collisional oblique shocks.Colliding plasmas have been studied in a variety of contexts, e.g., counterstreaming laser-produced plasmas supporting hohlraum design for indirect-drive inertial confinement fusion [1][2][3], forming and studying astrophysically relevant shocks [4][5][6][7][8], and for applications such as pulsed laser deposition [9] and laser-induced breakdown spectroscopy [10]. Physics issues arising in these studies include plasma interpenetration [11][12][13][14][15][16], shock formation [17], and the formation and dynamics of a stagnation layer [18][19][20]. In this work, we present experimental results on two obliquely merging supersonic plasma jets, which are in a different and more collisional parameter regime than many of the colliding plasma examples mentioned above. Ours and other recent jet-merging experiments [21,22] were conducted to explore the feasibility of forming imploding spherical plasma liners via an array of merging plasma jets [23][24][25][26][27], which could have applications in forming cm-, µs-, and Mbar-scale plasmas for fundamental high-energy-density-physics studies [28] and as a standoff driver for magnetoinertial fusion [23,[29][30][31][32]. Prior experiments studying the stagnation layer between colliding laser-produced or wire-array z-pinch [33] plasmas were on smaller spatial scales (mm or smaller) that could not be fully resolved by measurements. New results in the present work are the experimental identification and characterization of a few-cm thick stagnation layer between colliding plasmas, and the demonstration that our observations are consistent with hydrodynamic oblique shock theory [34].Experiments reported here are conducted on the Plasma Liner Experiment (PLX) [35], in which two supersonic argon plasma jets are formed and launched by plasma railguns [36]. Plasma jet parameters at the exit of the railgun nozzle (peak n e ≈ 2 × 10 16 cm −3 , peak T e ≈ 1.4 eV, V jet ≈ 30 km/s, Mach number M ≡ V jet /C s,jet ≈ 14, diameter = 5 cm, and length ≈ 20 cm) and their evolution during subsequent jet propagation have been characterized in detail [35]. The jet magnetic field inside the railgun is ∼3 T, but the classical magnetic diffusion time is a few µs [35], and thus • apart, two merging plasma jets, R-Z coordinates used in the paper, approximate interferometer/spectrometer linesof-sight (Z ≈ 84 cm), and CCD camera field-of-view.we ignore the effects of a magnetic field by the time of jet merging (> 20 µs). Experimental data ...

show abstract

Charge resolved electrostatic diagnostic of colliding copper laser plasma plumes

Abstract: The collision of two laser generated plasma plumes can result, under appropriate

Cited by 28 publications

References 86 publications

Experimental evidence for collisional shock formation via two obliquely merging supersonic plasma jets

Experimental evidence for collisional shock formation via two obliquely merging supersonic plasma jets

Atomic mass dependent electrostatic diagnostics of colliding laser plasma plumes

Experimental Characterization of the Stagnation Layer between Two Obliquely Merging Supersonic Plasma Jets

Contact Info

Product

Resources

About