Diagnostic and Power Feed Upgrades to the MAIZE Facility

Campbell, P. C.; Woolstrum, J. M.; Antoulinakis, Foivos; Jones, Trevor; Yager-Elorriaga, D. A.; Miller, Stephanie M.; Jordan, Nicholas M.; Lau, Y. Y.; Gilgenbach, R. M.; McBride, R. D.

doi:10.1109/tps.2018.2858796

Cited by 10 publications

(5 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A curved, dome-shaped transmission line would provide the least possible induction for this kind of path [28]. However, given that a conical power feed is not far from the optimal inductance and is much simpler in design and fabrication, it still represents a good solution for small-and medium-scale laboratory environments [29].…”

Section: Vacuum Power Feedmentioning

confidence: 99%

“…The discrepancy between measured and model current waveforms at later times (t ≥ 220 ns), when the B-dot current trace becomes nearly flat instead of following the LC oscillation, is likely due to the formation of plasma in the vacuum feed. Plasma in the feed region could shunt the driver current upstream of the B-dot location (for example, as a result of flashover at the surface of the vacuum insulator), or it could surround the probe [29]. In both cases, the magnetic flux change seen by the probe would be greatly reduced.…”

Section: Circuit Model and Machine Short-circuit Testsmentioning

confidence: 99%

“…In both cases, the magnetic flux change seen by the probe would be greatly reduced. After the current peak, the energy flux and E × B drift velocity reverse direction and point outward (power reversal) [9,29], which can cause plasma to be emitted by the feed electrodes via the inverse skin effect and propagate upstream toward larger radii. This phenomenon is not expected to affect experiments on the CESZAR driver, which will largely be limited to a timescale ≤220 ns, in order to achieve high-energy coupling given the machine rise time.…”

Section: Circuit Model and Machine Short-circuit Testsmentioning

confidence: 99%

See 2 more Smart Citations

MA-class linear transformer driver for Z -pinch research

Conti

Valenzuela

Fadeev

et al. 2020

Phys. Rev. Accel. Beams

View full text Add to dashboard Cite

A linear transformer driver (LTD) generator capable of delivering up to 0.9 MA current pulses with 160 ns rise time has been assembled and commissioned at University of California San Diego. The machine is an upgrade of the LTD-III pulser from Sandia National Laboratories, consisting of 40 capacitors and 20 spark gap switches, arranged in a 20-brick configuration. The driver was modified with the addition of a new trigger system, active premagnetization of the inductive cores, a vacuum chamber with multiple diagnostic ports, and a vacuum power feed to couple the driver to plasma loads. The new machine is called compact experimental system for Z-pinch and ablation research (CESZAR). The driver has a maximum bipolar charge voltage of AE100 kV, but for reliability and testing, and to reduce the risk of damage to components, the machine was operated at AE60 kV, producing 550 kA peak currents with a rise time of 170 ns on a 3.5 nH short circuit. While the peak current is scaled down due to the reduced charge voltage, the pulse shape and circuit parameters are close to the results of the cavity and power feed models but suggest a slightly higher inductance than predicted. The machine was then used to drive wire array Z-pinch and gas puff Z-pinch experiments as initial dynamic plasma loads. The evolution of the wire array Z pinch is consistent with the general knowledge of this kind of experiment, featuring wire ablation and stagnation of the precursor plasma on axis. The gas puff Z pinches were configured as a single, hollow argon gas shell, in preparation for more structured gas puff targets such as multispecies, multishell implosions. The implosion dynamics agree generally with 1D magnetohydrodynamics simulation results, but large zippering and magneto-Rayleigh-Taylor instabilities are observed. The CESZAR load region was designed to accommodate many load types to be driven by the machine, which makes it a versatile platform for studying Z-pinch plasmas. The completion of the CESZAR driver allows plasma experiments on energy coupling from LTD machines to plasma loads, instability mitigation techniques and magnetic field distributions in Z pinches, and interface dynamics in multispecies implosions.

show abstract

Section: Vacuum Power Feedmentioning

confidence: 99%

Section: Circuit Model and Machine Short-circuit Testsmentioning

confidence: 99%

Section: Circuit Model and Machine Short-circuit Testsmentioning

confidence: 99%

See 1 more Smart Citation

MA-class linear transformer driver for Z -pinch research

Conti

Valenzuela

Fadeev

et al. 2020

Phys. Rev. Accel. Beams

View full text Add to dashboard Cite

show abstract

“…Optimized power feeds are often evaluated while simultaneously considering several other design constraints (e.g., avoiding other experimental equipment and/or diagnostics). More often than not, though, a simple conical power feed is not far from the optimum and in fact works quite well in practice [66].…”

Section: Systemmentioning

confidence: 99%

A Primer on Pulsed Power and Linear Transformer Drivers for High Energy Density Physics Applications

McBride

Stygar

Cuneo

et al. 2018

IEEE Trans. Plasma Sci.

Self Cite

View full text Add to dashboard Cite

“…Such experiments can be used to study the initial plasma formation and ablation dynamics and different kinds of perturbation development for the exploding liner in vacuum which are important factors in the quality of the final implosion. Campbell et al have investigated magnetohydrodynamic (MHD) instabilities on the Michigan Accelerator for Inductive Z-Pinch Experiments (MAIZE) [7,8]. Rousskikh et al studied the initial corecorona structure in exploding foils [9,10].…”

Section: Introductionmentioning

confidence: 99%

Ablated precursor plasma and evolution of magnetic field of exploding cylindrical thin liner

Zhang¹,

Wu²,

Chen³

et al. 2021

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

The formation of precursor plasma and ablation dynamics of Al thin liner explosion are investigated in this manuscript. The size of 12 mm in diameter, 10 μm in thickness Al liners are exploded on the Qin-1 facility (about 450 ns, 450 kA). An axial laser shadowgraphy and interferometry platform is set up to observe the plasma dynamics inside the liner. To solve the problem that the inside plasma density of the liner cannot be absolutely calibrated due to the lack of a zero plasma density area, we have established a CW laser interference system using a streak camera which can trace the interference lines over time. Low-density (10−7−10−6 g cm−3) precursor plasma is generated from the interior wall and flows towards the center with a velocity of about 150–200 km s−1, thus forming a column with high electron density by accumulation. Simultaneously, a high-density plasma layer flows toward the center at about 10 km s−1. The electron density of the central plasma column rises up rapidly after the precursor reaches the center and achieves 2.5 × 1018 cm−3 at 280 ns after the current starts. To fully understand the process, we have used the resistive magnetohydrodynamic code FLASH to realize a simulation to study interior precursor dynamics. We compared these simulation results with our experiments. Finally, we measured the voltage for the whole process and derived the inductance change and effective current radius. We compared the simulated current density distribution with the experimental result which proves that a considerable amount of current flows through the center plasma column, making the effective radius of current become smaller over time.

show abstract

Diagnostic and Power Feed Upgrades to the MAIZE Facility

Cited by 10 publications

References 24 publications

MA-class linear transformer driver for Z -pinch research

MA-class linear transformer driver for Z -pinch research

A Primer on Pulsed Power and Linear Transformer Drivers for High Energy Density Physics Applications

Ablated precursor plasma and evolution of magnetic field of exploding cylindrical thin liner

Contact Info

Product

Resources

About