Anyone want muzzle velocity?

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Preacherman

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The report below makes interesting reading. Converting to feet per second, this is more than 111,000 fps!!! :what:

I wonder if they can apply this technology to the emerging designs for rail guns and other electromagnetic-propulsion weapons?


From RedNova (http://www.rednova.com/news/display/?id=154480&source=r_technology):

Posted on: Tuesday, 7 June 2005, 18:05 CDT

The Fastest Gun in the West

ALBUQUERQUE, N.M. -- Sandia National Labs has accelerated a small plate from zero to 76,000 mph in less than a second.

The speed of the thrust was a new record for Sandia's Z Machine - sometimes referred to as the fastest gun in the West. Actually the fastest in the world, it is now able to propel small plates at 34 kilometers a second, faster than the 30 km/sec that Earth travels through space in its orbit about the sun, 50 times faster than a rifle bullet, and three times the velocity needed to escape Earth's gravitational field.

Sandia is a National Nuclear Security Administration lab.

The immediate purpose of these very rapid flights is to help understand the extreme conditions found within the interiors of the giant planets Saturn and Jupiter, hasten the achievement of virtually unlimited energy through peacetime atomic fusion, and provide more information about the condition of the U.S. nuclear stockpile without having to explode a nuclear weapon.

"This is one of the few ways on earth to get hard information on problems at the outer reaches of science, rather than having to rely on complex speculations that may or may not be correct," says Marcus Knudson, lead scientist on the effort.

Z's hurled plates strike a target after traveling only five millimeters. The impact generates a shock wave - in some cases, reaching 15 million times atmospheric pressure - that passes through the target material. The waves are so powerful that they turn solids into liquids, liquids into gases, and gases into plasmas in the same way that heat melts ice to water or boils water into steam.

The difference is that the process takes place at far higher temperatures and in much shorter times than the kitchen stove could ever approach. The pressures produce states of materials rarely seen or measured in the laboratory. Says Yogi Gupta, a professor known for his work in shock physics at the Washington State University in Pullman, "If you had asked me a few years ago if we could send something this fast, I would have said you were joking. But mankind is always trying to create conditions in the laboratory that imitate extreme conditions [found elsewhere]."

When shock waves penetrate a capsule containing deuterium (an isotope of hydrogen), researchers learn more about how hydrogen behaves under extreme conditions, providing more information for humanity's effort to eventually achieve controlled nuclear fusion, the process that drives the sun. Harnessed in a power plant, this potentially low-environmental-impact method could achieve virtually unlimited energy from sea water.

By creating states of matter extremely difficult to achieve on Earth, the flyer plates also provide hard data to astrophysicists speculating on the structure and even the formation of planets like Jupiter and Saturn. Says Didier Saumon, an astrophysicist at Los Alamos National Laboratory, "The internal structures of Jupiter and Saturn are composed mostly of hydrogen, so knowing its equation of state [how hydrogen and its isotopes behave at pressures from one to 50 million atmospheres] is highly relevant to how we infer the interior properties of these planets. Z gave us hard data."

A paper on the flyer plate results, first presented in a technical talk to the American Physical Society, has been submitted to the Journal of Applied Physics.

More technical information

The plates are small - only 30 mm by 15 mm in cross-section, and 850 microns thick. The trick in accelerating the fragile aluminum plates at 10-to-the-10th Gs (force of Earth's gravity) without vaporizing them lies in the finer control now achievable of the magnetic field pulse driving the flight.

The arrival of energy at the target is staggered over three hundred nanoseconds, so that the amperage arrives less like a brick wall that would vaporize the plate and more in controllable increments.

This requirement was better achieved by a recent upgrade that removed a single laser formerly used to trigger current in Z's thirty-six cables simultaneously. In its place, 36 laser switches were installed - one for each cable. This change permits researchers to shape the electrical pulse that arrives at the target, with a corresponding modulation in the magnetic field driving the plate.

An upgrade of Z planned for next year is expected to achieve plate velocities of 45 to 50 km/sec, says Marcus, driving targeted materials further into their plasma regime.

Z's former record in propelling plates was 21 km/sec, set two years ago.
 
heh heh, i wonder what the felt recoil on that thing is like....

edit: well, i just read this near the bottom of the article:

"The plates are small - only 30 mm by 15 mm in cross-section, and 850 microns thick."

i'm guessing that's a really really light weight plate. plus electro magnetic stuff...well i guess that kinda kills any recoil?
 
he impact generates a shock wave - in some cases, reaching 15 million times atmospheric pressure - that passes through the target material. The waves are so powerful that they turn solids into liquids, liquids into gases, and gases into plasmas

So very cool.

-James
 
Looks cool.

Their idea of CQB is a little close for me, though.

"Z's hurled plates strike a target after traveling only five millimeters".

I'd want to be a little farther away than that from something that "turn solids into liquids, liquids into gases, and gases into plasmas"!
 
Look, the range on this thing is horrible, I mean....what if your target is, say, TEN millimeters away....what's the impact energy then? And...and...can we be sure these plates achieve localized fusion EVERY time they hit? What if the guy's wearing a thick jacket?
 
:( I interviewed for a job as a technician working on that beast! It was called PBFA2 at the time. I would have had to take scuba training to work on it! Someone else got the job, darnit. :banghead:

z_30.jpg


Article on the Z machine
 
Sandia’s Z Pinch is a further refined device used to dabble in fusion and understanding developing planetoids and stars, not really a weapon persay. However it’s pretty darn impressive. They basically explode an array of very thin wires with pulsed power, turn it into an ionized gas, and compress it with the resultant magnetic field until things heat up to millions of degrees.

Whereas in everyday life you see energy radiated as luminescent light (ie lightbulb), the intensity of the radiated energy from the Z Pinch is in the electromagnetic wavelength of X-rays.

The peak pulsed power last I read was approaching 300 terawatts (trillion watts) which is something on the order of 80x the electrical output of the world combined.

You can find images of the Z Pinch firing. The most famous one is a wide-angle photo showing electrical discharges and dielectric crawl on the surface of the water-insulated transmission cables leading to the firing chamber. (warning, mondo image: http://www.sandia.gov/media/images/jpg/Z02.jpg)

If you want the really cool futuristic stuff, look into railguns, linear coil guns, and electromagnetic launchers as a bit more practical to develop into weaponry with advancing power storage technologies and material sciences. Capacitors are getting better and UT-CEM have been working on developing pulsed compensated alternators.

I’ve seen a 3m railgun (not in person) fire a 1gram polycarbonate projectile at 7km/s and blow apart a 1” plate of aluminum which is pretty impressive. There is another facility at ISL that is approaching 40% efficiency (which is really incredible!) I built a crude one myself back in college but it was nowhere near the budget, efficiency, or spectacular as government funded projects. If there are any electrical engineers here, IEEE Transactions on Magnetics has hundreds of papers on railguns. Most of the weapon-oriented ones are hurling 1-2 pound sabot projectiles objects at a couple miles per second. There are a lot of neat pictures of destroyed targets, the actual railgun, projectiles, and of course, lots of details and graphs for the technical-minded.

Who says science isn’t fun?

*edit oops someone beat me to the punch on the image
 
Sandia's Z machine isn't very concealable for CCW...unless you're a warehouse...

I've seen that photo of the electrical discharges tracing over the water. Awesome.

One thing that is really futuristic? Compact toroid generators...the directed-energy-weapon kind...
 
Whats a directed energy toroiodal generator?

The only energetic donut-shaped, high-tech thing I can think of are those experimental Tokamak or stellarator fusion reactors :confused:

You can make a concealable coilgun that'll fire small ferromagnetic projectiles like nails with little more than a disposable camera's flashtube charging circuit and some magnet wire. It might scare a cat and poke a hole in a pop can but it won't take down a badguy...good science project for the kids.
 
"peak pulsed power last I read was approaching 300 terawatts (trillion watts)"

How many AA batteries does that translate into? :what: :neener:
 
Toroid is a different way to set up the magnets. They twist around the donut instead of being perpendicular to them. They require less power than Tokomaks, but don't produce as much pressure and such.
 
Going off machine specs itself, it claims to release over 2MJ (million joules) in radiated (X-ray) energy alone. A Physics News paper I hunted down states the stored energy amounts to a 12MJ capacitor bank so I'll use this figure

Assuming I get all the decimals right (and I'll stick numbers here if anyone wants to verify), the 15mmx30mmx.85mm object has a volume of .3825cc. Al has a density of .26989g/cc according to MatWeb so the aluminum disk weighs 1.032g

I get 11933 joules of kinetic energy using the standard Ek=1/2mv^2 formula. It sounds like the correct magnitude since the mass is very minimal.

So, the efficiency of this device, taking the assumption it's main design goal is to accelerate this projectile, is .099% :D
 
Not that kind of compact toroid, this kind:

DEGNAN, J., R. PETERKIN, et al. (1993). “COMPACT TOROID FORMATION, COMPRESSION, AND ACCELERATION.” PHYSICS OF FLUIDS B-PLASMA PHYSICS 5(8): 2938-2958.

Research on forming, compressing, and accelerating milligram-range compact toroids using a meter diameter, two-stage, puffed gas, magnetic field embedded coaxial plasma gun is described. The compact toroids that are studied are similar to spheromaks, but they are threaded by an inner conductor. This research effort, named MARAUDER (Magnetically Accelerated Ring to Achieve Ultra-high Directed Energy and Radiation), is not a magnetic confinement fusion program like most spheromak efforts. Rather, the ultimate goal of the present program is to compress toroids to high mass density and magnetic field intensity, and to accelerate the toroids to high speed. There are a variety of applications for compressed, accelerated toroids including fast opening switches, x-radiation production, radio frequency (rf) compression, as well as charge-neutral ion beam and inertial confinement fusion studies. Experiments performed to date to form and accelerate toroids have been diagnosed with magnetic probe arrays, laser interferometry, time and space resolved optical spectroscopy, and fast photography. Parts of the experiment have been designed by, and experimental results are interpreted with, the help of two-dimensional (2-D), time-dependent magnetohydrodynamic (MHD) numerical simulations. When not driven by a second discharge, the toroids relax to a Woltjer-Taylor equilibrium state that compares favorably to the results of 2-D equilibrium calculations and to 2-D time-dependent MHD simulations. Current, voltage, and magnetic probe data from toroids that are driven by an acceleration discharge are compared to 2-D MHD and to circuit solver/slug model predictions. Results suggest that compact toroids are formed in 7-15 musec, and can be accelerated intact with material species the same as injected gas species and entrained mass greater-than-or-equal-to 1/2 the injected mass.

I did some reading on the MARAUDER program once. The toroid is self-propagating (sort of like a magnetic smoke ring) and carries considerable kinetic energy. One discharge broke some pretty thick bolts securing the target, as I recall.
 
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