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Plasma expansion in a negative-polarity rod-pinch diode

IEEE Transactions on Plasma Science

Leckbee, Joshua; Johnston, Mark D.; Oliver, Bryan V.

The negative-polarity rod-pinch diode is being developed and tested on the RITS-6 accelerator to expand radiographic capabilities. High current densities at the tip of the rod anode generate a plasma which expands at a rate of 2-4 cm μs. Images of visible light captured with a high-speed intensified charge-coupled device camera show the development and expansion of the plasma. © 2006 IEEE.

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TYPE Journal Article YEAR 2011
OSTIScopus

Option study of an orthogonal X-ray radiography axis for pRad at LANSCE area C, Los Alamos

Oliver, Bryan V.; Leckbee, Joshua

We report on an option study of two potential x-ray systems for orthogonal radiography at Area C in the LANSCE facility at Los Alamos National Laboratory. The systems assessed are expected to be near equivalent systems to the presently existing Cygnus capability at the Nevada Test Site. Nominal dose and radiographic resolution of 4 rad (measured at one meter) and 1 mm spot are desired. Both a system study and qualitative design are presented as well as estimated cost and schedule. Each x-ray system analyzed is designed to drive a rod-pinch electron beam diode capable of producing the nominal dose and spot.

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TYPE SAND Report YEAR 2010
DOIOSTI

Load line evaluation of a 1-MV linear transformer driver (LTD)

Proceedings of the 2008 IEEE International Power Modulators and High Voltage Conference, PMHVC

Leckbee, Joshua; Cordova, Steve R.; Oliver, Bryan V.; Johnson, David L.; Toury, Martial; Rosol, Rodolphe; Bui, Bill

A seven cavity LTD system has been assembled and tested in a voltage adder configuration capable of producing approximately 1-MV into a 7-Ω, critically damped load. Individual cavities have been tested with a resistive load. The seven cavity adder has been tested with a large area electron beam diode. The output pulse when tested into a resistive load is that of an RLC circuit. When tested with a dynamic load impedance, the output voltages of the cavities have an added oscillation. The oscillation affects the output pulse shape but is not harmful to the cavity components. © 2008 IEEE.

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TYPE Conference YEAR 2008
ScopusOSTI

Design of a 7-MV Linear Transformer Driver (LTD) for down-hole flash x-ray radiography

Leckbee, Joshua; Oliver, Bryan V.

Pulsed power driven flash x-ray radiography is a valuable diagnostic for subcritical experiments at the Nevada Test Site. The existing dual-axis Cygnus system produces images using a 2.25 MV electron beam diode to produce intense x-rays from a small source. Future hydrodynamic experiments will likely use objects with higher areal mass, requiring increased x-ray dose and higher voltages while maintaining small source spot size. A linear transformer driver (LTD) is a compact pulsed power technology with applications ranging from pulsed power flash x-ray radiography to high current Z-pinch accelerators. This report describes the design of a 7-MV dual-axis system that occupies the same lab space as the Cygnus accelerators. The work builds on a design proposed in a previous report [1]. This new design provides increased diode voltage from a lower impedance accelerator to improve coupling to low impedance diodes such as the self magnetic pinch (SMP) diode. The design also improves the predicted reliability by operating at a lower charge voltage and removing components that have proven vulnerable to failure. Simulations of the new design and experimental results of the 1-MV prototype are presented.

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TYPE SAND Report YEAR 2008
DOIOSTI
Results 51–75 of 89
Results 51–75 of 89