The little beam that could

February 01, 2006

Scientists at Los Alamos National Laboratory, in collaboration with researchers from the University of Nevada, Reno, Ludwig-Maximilian-University in Germany, and the Max-Planck-Institute for Quantum Optics in Germany, have developed a new method for using a laser beam to accelerate ions. The novel method may enable important advances in compact ion accelerators, medical physics and inertial confinement fusion.

In a paper published in a recent issue of the scientific journal Nature, a team led by Los Alamos scientist Manuel Hegelich describe their method for the laser acceleration of a monoenergetic ion beam. The carbon ion beam researchers created using the Trident laser facility at Los Alamos had an energy level of 3 Megaelectronvolt (MeV) per nucleon, or 36 MeV.

Scientists have known about laser-driven ion beams with energies in the MeV range for several years, but the Los Alamos team's experiment was the first to establish the basis for laser-driven acceleration of monoenergetic ion beams using specifically designed and treated targets. While the energy spread of laser-driven ion beams is still substantially larger than in conventional accelerators, in several respects they surpass conventional beams.

According to Hegelich, "Typically you need a very large accelerator, the kind that only fits in a research hall, and that accelerates particles over distances of around a hundred meters, to accelerate

an ion beam to the energies reported in our paper. Even then, the resulting ion pulses are longer and have weaker currents (milli- or even microamps versus kiloamps). Because conventional accelerators are currently pushing the limits in size and cost, laser acceleration is a potential solution to these challenges. The laser-driven ion accelerator we've developed fits in a typical-sized laboratory and the accelerate ions over a distance of roughly 10 microns."

Because of its compact device size and unique beam characteristics, laser-accelerated ions have potential in the treatment of certain types of brain tumors, in lieu of conventional x-rays or protons. German medical researchers have already developed methods for using carbon ions to place almost all of the beam's energy in a tumor. Conventional tumor treatment methods typically deposit large amounts of radiation in the tumor as well as in surrounding healthy tissue. Producing the ion beams, however, has required large accelerator devices in the several hundred million-dollar range. The laser acceleration method has the potential to shrink both the size and cost of the required accelerator devices.

Laser acceleration also shows potential for use as a "sparkplug" in inertial confinement fusion (ICF). In conventional ICF, a fusion fuel is simultaneously compressed and heated by a laser driver until it reaches in its core the conditions needed for ignition. In an ICF concept called "fast ignition," the compression and ignition parts are separate and the long-pulse laser is first used to compress the fuel. Then, at the moment of maximum compression, the laser-driven ion beam is used as a "sparkplug" to ignite fusion. With very short pulse durations, laser-produced ions might possess the energy needed to ignite fusion at maximum compression.
-end-
Los Alamos National Laboratory is operated by the University of California for the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy and works in partnership with NNSA's Sandia and Lawrence Livermore national laboratories to support NNSA in its mission.

Los Alamos develops and applies science and technology to ensure the safety and reliability of the U.S. nuclear deterrent; reduce the threat of weapons of mass destruction, proliferation and terrorism; and solve national problems in defense, energy, environment and infrastructure.

For more Los Alamos news releases, visit World Wide Web site http://www.lanl.gov/news/index.php?fuseaction=nr.subject

DOE/Los Alamos National Laboratory

Related Laser Articles from Brightsurf:

Laser technology: New trick for infrared laser pulses
For a long time, scientists have been looking for simple methods to produce infrared laser pulses.

Sensors get a laser shape up
Laser writing breathes life into high-performance sensing platforms.

Laser-powered nanomotors chart their own course
The University of Tokyo introduced a system of gold nanorods that acts like a tiny light-driven motor, with its direction of motion is determined by the orientation of the motors.

What laser color do you like?
Researchers at the National Institute of Standards and Technology (NIST) and the University of Maryland have developed a microchip technology that can convert invisible near-infrared laser light into any one of a panoply of visible laser colors, including red, orange, yellow and green.

Laser technology: The Turbulence and the Comb
While the light of an ordinary laser only has one single, well-defined wavelength, a so-called ''frequency comb'' consists of different light frequencies, which are precisely arranged at regular distances, much like the teeth of a comb.

A laser for penetrating waves
The 'Landau-level laser' is an exciting concept for an unusual radiation source.

Laser light detects tumors
A team of researchers from Jena presents a groundbreaking new method for the rapid, gentle and reliable detection of tumors with laser light.

The first laser radio transmitter
For the first time, researchers at Harvard School of Engineering have used a laser as a radio transmitter and receiver, paving the way for towards ultra-high-speed Wi-Fi and new types of hybrid electronic-photonic devices.

The random anti-laser
Scientists at TU Wien have found a way to build the 'opposite' of a laser -- a device that absorbs a specific light wave perfectly.

Laser 'drill' sets a new world record in laser-driven electron acceleration
Combining a first laser pulse to heat up and 'drill' through a plasma, and another to accelerate electrons to incredibly high energies in just tens of centimeters, scientists have nearly doubled the previous record for laser-driven particle acceleration at Berkeley Lab's BELLA Center.

Read More: Laser News and Laser Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.