Posts Tagged ‘argon’
Chip-Sized Particle Accelerators Could Lead to Cancer-Fighting Ray Guns
OK, so it can’t reach the energies produced at the LHC or Tevatron, but this is still pretty impressive. Engineers at a micro-electro mechanical systems conference last week unveiled this tiny cyclotron device, which can speed argon ions down a 5-millimeter accelerator track.
The ions have 1.5 kiloelectron volts of energy and pick up another 30 electronvolts when they whiz around a 90-degree turn, as IEEE Spectrum explains. That is peanuts compared to the 3.5 teraelectron volts currently experienced at the LHC, but hey, this chip is several orders of magnitude smaller than that massive series of tubes.
Unlike most other accelerators, this device skips magnets and instead uses an electrical field to accelerate and steer its particles through a pair of electrodes.
The goal is a suitcase-sized accelerator capable of producing 1 MeV, which would make it powerful enough for a wide range of uses, according to the chip’s creators at Cornell University. Such a device could be used to make smaller scanning electron microscopes or portable ray guns to fight cancer, rather than installing particle accelerators inside hospitals, for instance: “Think of a scalpel with a proton beam coming out of it,” said Amit Lal, who worked with chip-builder Yue Shi and leads Cornell’s SonicMEMS Laboratory.
A few hurdles remain, including a more efficient way to grab ions from the 75-micrometer-wide beam. Lots of ions are lost in the transition, Shi said. But the device at least proves the concept that you don’t need humongous frozen magnets and cavernous spaces to speed up some particles.
DARPA is funding the work, which is ongoing at Cornell.
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Giant Gravel Batteries Could Make Wind Power a Reliable Energy Option
The battery consists of two large silos filled with crushed rock. Electricity generated by the turbine heats and pressurizes argon gas and feeds it into the first silo. The gravel is heated to more than 900 degrees as the hot, pressurized argon passes through, though by the time the argon leaves the chamber it has cooled to ambient temperature.
The argon is then fed into the second silo where it returns to normal atmospheric pressure, initiating a cooling effect that chills the gas and rock to -256 degrees. Thus, the electricity is stored as a temperature difference between the two chambers. If the wind ceases to blow, the process is reversed, feeding the cold gas back into silo number one, powering a generator as it makes the transition back to hot from cold.
The process isn't a perfect closed energy loop, but Isentropic claims a complete trip through the cycle retains up to 80 percent of the original electricity. Even better, gravel is cheap; the cost per kilowatt-hour falls somewhere between $10 and $55, depending on the costs of other materials. Isentropic also claims the batteries are highly durable; according to the company's founder, a 164-foot tall silo with an equal diameter would retain half its energy even if left untouched for three years.
All that sounds pretty good, but Isentropic has yet to fully prove out the idea. The vast temperature differences generated by the argon sound quite drastic, and the director of the UK Energy Research Centre points out, gravel isn't the ideal material to have inside of machine with moving parts. As such, Isentropic is designing a pilot plant that could store 16 megawatt-hours in two silos just 23 feet tall by 23 feet in diameter. That's enough to cover a pretty big neighborhood during a long, windless stretch. The company is also in talks with an unnamed utility to build a larger demonstration facility.
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