NRL materials testing facility

Meger, R. A.; Huhman, B. M.; Neri, J. M.; Brintlinger, Todd; Jones, H.N.; Cairns, Richard L.; Douglass, S.R.; Lockner, T.R.; Sprague, J.A.

doi:10.1109/eml.2012.6325174

Cited by 4 publications

(3 citation statements)

References 4 publications

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“…The NRL Materials Testing Facility (MTF) houses a 6-m, 1.5 MA, 40x50 mm 2 cross section bore; hypersonic launcher used primarily to study bore life issues [1]. The launcher utilizes a 304 stainless steel containment structure supported by a non-conducting platform.…”

Section: Methodsmentioning

confidence: 99%

EM gun bore life experiments at the Naval Research Laboratory

Meger

Cairns

Douglass

et al. 2012

2012 16th International Symposium on Electromagnetic Launch Technology

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The Naval Research Laboratory (NRL) performs basic and applied research on high power railguns as part of the US Navy EM Launcher program. The understanding of damage mechanisms as a function of armature and barrel materials, launch parameters, and bore geometry is of primary interest to the development of a viable high power railgun. Research is performed on a 6m, 1.5 MJ railgun located at NRL. Barrel studies utilize in situ diagnostics coupled with detailed ex situ analysis of rail materials to provide clues to the conditions present during launch. Results are compared with coupled 3-D electromagnetic and mechanical Finite Element Analysis (FEA) models of railgun operation. Results of several experiments on rail wear will be discussed.

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Section: Methodsmentioning

confidence: 99%

EM gun bore life experiments at the Naval Research Laboratory

Meger

Cairns

Douglass

et al. 2012

2012 16th International Symposium on Electromagnetic Launch Technology

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“…The Material Test Facility (MTF) [8] is a 6.1-m long (240 in) railgun that is designed to test various rail and armature materials under high-stress launch conditions. To facilitate testing of these materials, the MTF uses six 1-m (40 in) 0093-3813 © 2015 IEEE.…”

Section: Mtf Descriptionmentioning

confidence: 99%

Diagnostics for Kinematics on MTF at NRL

Douglass

Reid

Meger

et al. 2015

IEEE Trans. Plasma Sci.

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The Material Test Facility (MTF) houses a medium-caliber electromagnetic (EM) railgun that is designed for ease of access. As such, it is ideal for developing diagnostics for measuring the performance of EM launchers. Multiple in situ diagnostics have been fielded on the MTF railgun including field sensors for position location and thermal sensors. Kinematics of the launch package are of particular interest. B-dot loops are the usual method, but many such B-dots are required to obtain a detailed evolution of position and velocity. This requires many channels and consumes data acquisition resources. Naval Research Lab (NRL) has developed several versions of a flux ladder diagnostic, which include many pick-up loops on one data channel. Some versions have multiple flux ladders interleaved to maintain pulse separation in a single channel, but which increase the overall spatial resolution. A typical MTF configuration has 58 positions monitored in just three channels. Careful processing has yielded velocity and even acceleration. NRL is also developing a flux loop diagnostic that has the potential for continuous kinematics with the time resolution of the digital sampling rate. However, flux loops are more sensitive to spurious signal sources. Preliminary flux loop results are presented.

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“…Since relatively a large PPS is needed to deliver such a current waveform, experimental studies on the electromagnetic launcher are being done only in a few countries [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

Electromagnetic launch experiments using a 4.8 MJ pulsed power supply

Yang

Kim

Lee

et al. 2014

2014 17th International Symposium on Electromagnetic Launch Technology

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After preliminary tests using a small 25 mm-caliber electromagnetic launcher, a larger mid-caliber launcher has been designed and fabricated. The launcher has a rectangular bore of 40 mm x 50 mm where the rails are separated by 50 mm each other and are 5.6 m long. To deliver an electrical current to the launcher, a new 4.8 MJ pulsed power supply (PPS) consisting of eight 600 kJ segments has been constructed. The 600 kJ segment is a basic building block of PPS operated independently. It contains a controller, a charger, a safety circuit, and six 100 kJ unit modules. Each unit module in the segment is composed of a 100 kJ capacitor bank, a thyristor switch, a crowbar diode, and a pulse-forming inductor. The modules in a segment are charged to the same voltage, but they are designed to have different triggering times to make a flexible shape of current waveform. Electrical parameters of the PPS were determined through the discharges of the unit modules, and those of the rails were done by launch experiments or short circuit tests at the ends of the rails. Launch experiments have been done using several current waveforms. The current of 1 MA in a few ms made the armatures of several hundred grams in mass accelerate to velocities near 2 km/s. In this paper, the design and basic performance of the constructed PPS and the electromagnetic launcher are presented.

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NRL materials testing facility

Cited by 4 publications

References 4 publications

EM gun bore life experiments at the Naval Research Laboratory

EM gun bore life experiments at the Naval Research Laboratory

Diagnostics for Kinematics on MTF at NRL

Electromagnetic launch experiments using a 4.8 MJ pulsed power supply

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