CERN in a Shoebox? Tiny Particle Accelerators Are Coming

Scientists may soon make particle accelerators that can be the size of a shoebox, experts says.

The project, which is still in its early stage, will use lasers instead of microwaves, to accelerate particles to nearly speed of light.

Applying lasers, "you are able to accelerate particles through short distances to obtain  a higher energy," said Joel England, a researcher from SLAC National Accelerator Laboratory at Menlo Park, California, and one of the main researchers involved in the project.

The earliest type of this technology may probably be used in medical physics and experiments to observe atoms in real time, experts say.If the new method works-out, it may gradually be scaled up to size as that of the world's largest atom smashers, and further decentralize the field of particle physics.

Thinking big as well as small

When talking about particle accelerators,virtually all physicists think big. Giant underground rings that cover country borders. Left-over mineshafts and undergoung structures buried deep beneath the Earth. Tunnels with length long enough to measure from one end of Los Angeles to another. The effective physics needs higher energies, and higher energies need longer distances to ramp up speed.

Such ambitious moves are hugely expensive, and that means only a priviledge few are able to perform  particle-physics experiments. In real life,just around 30,000 accelerators are available worldwide, according to Symmetry Magazine. It sounds like a glut, but there's usually a long queue to use even lower-energy accelerators, England said.Even lower-energy particle accelerators still needs huge expanse of space — a luxury only handful universities can afford, he added.

That's because particle colliders recently rely on microwaves to boost particle energy, England said.Since microwaves have a long wavelength — between 0.04 inches and 39 inches (0.1 centimeters to 100 cm) — meaning they take a longer distance to boost a particle's energy.

Recent microwave amplifiers used in particle accelerators resemble a microwave oven in certain ways, England said.

It encloses a cavity within metal container that you pump microwave power into and it sets up a field in within, England said. "Rather cooking dinner, it produces a different type of field with an electric component placed along the axis so that particles passes through will receive a kick."

Laser accelerator

In recent times, laser technology has improved by leaps and bounds.Since lasers have a shorter wavelength (visible light has a wavelength that's between 400 nanometers and 700 nm), that means laser-driven accelerators could reduce in size significantly.

So, England and a huge group of experts have teamed up to make a laser-driven accelerator that can be mounted onto a microchip. [Infographic: How Do Lasers Work?]

"The main aim is to have all of the components needed to accelerate particles to useful energies,using the similar devices on a single silicon wafer," England told Live Science.

Lasers allow for higher field intensities,since they will not damage the metal cavities like microwaves would. In addition, microfabrication could allow researchers to fit hundreds of accelerators in series on a single wafer, England said.

The team proposes to make a working prototype in five years, and the project just received millions of dollars for funding from the Gordon and Betty Moore Foundation to make that come true. In the short run, the team proposes to generate smaller accelerator energies,similar to hospital radiation machines.

Eventually, the technology can be used to scale down the big colliders, such as the proposed International Linear Collider, a next-generation facility which may be built in Japan that would look for new forms of matter. It can also be used to repurpose existing accelerators, such as SLAC, said Robert Byer, an applied physicist at Stanford University involved in the project.

"If we have a smaller accelerator, we will be able to build a version of SLAC that's just 30 meters [98 feet] long, not 3 km [1.8 miles] long," Byer said. "You will save a lot of funds on tunnels and all civil construction."

Lots of obstacles

Although, reaching that point requires a lot of ingenuity.

As such,the team have not stumbled across source of particles that can be made using silicon wafer technology. This means the team will have to make one, possibly looking in the way of diamonds or silicon to emit electrons. Those electrons would then be ramped upto high speed by a focused laser beam, Byer said.

To such electrons within the highly focused beam required for particle acceleration will most likely need making tiny waveguides into the chip. The researchers also have to look for other ways to mount the laser to the other devices on the chip, Byer said.

New applications

One of the numerous possibilities is in the medical-treatment field, Byer said. Existing medical-radiation devices are enormously sized that may occupy an entire room, and radiation often strays to other parts of the body beyond the tumor.

If medical-radiation devices could be miniaturized to fit into a catheter, doctors could irradiate tumors with higher amount of radiation without damaging nearby tissue, Byer said. To do that, doctors could attach a catheter with a tiny accelerator into the body, and then destroy a tumor with electrons at a sufficiently low energy level that all the radiation would be stopped in the tumor tissue, Byer said.

Shoebox accelerators may also assist to reveal the mysterious inner details of the atom. Lasers can now accelerate bunches of electrons at the attosecond timescale, which is about "the same time it takes an electron to orbit the nucleus of an atom," Byer said.

Using such tiny time slices, "we'll be able to take movies of electrons in the orbits of atoms. We'll be able to watch electrons move to make the bonds."