Compact Gas Pedal Generates Tens Of Billions Of Electron Volts Of Energy By Letting Electrons Surf in The Laser's Wake

Particle gas pedals have great potential for semiconductor applications, medical imaging and therapy, and materials, energy and medical research. But traditional gas pedals require a large space to operate, are very expensive, and are available only in a few national laboratories and universities. According to the latest issue of the journal Matter and Radiation in Extreme Conditions, a team of researchers including the University of Texas at Austin has demonstrated a compact particle gas pedal less than 20 meters in length called the Advanced Laser Tail Field Accelerator, which produces an electron beam with an energy of 10 billion electron volts.
There are currently only two gas pedals in the U.S. that can reach such high electron energies, but both are 3 kilometers long. Now, researchers can achieve such high energies in a chamber within 10 centimeters.
Laser wake field gas pedals are based on the principle of shooting helium gas with an extremely powerful laser that heats it into a plasma and creates waves that knock electrons out of the gas, creating a high-energy electron beam. The concept has been widely publicized since it was proposed in 1979.
This time, the research team's key advance relies on nanoparticles. An auxiliary laser strikes a metal plate inside the gas chamber, which injects a stream of metallic nanoparticles that enhances the energy transferred from the wave to the electrons.
The laser, like a boat skimming the surface of a lake, leaves a wake, and the electrons ride this plasma wave like a wake surfer. The researchers compare this to the difficulty of a surfer getting into a wave uncontrolled, so typically a motorboat will drag the surfer into the wave. In the new gas pedal, the nanoparticles are the equivalent of a motorboat, releasing their electrons at the right point and at the right time, so they can all "surf" the tail wave.
In their experiments, the researchers used one of the world's most powerful pulsed lasers, the Texas Tile Laser, which emits an ultra-powerful pulse of light once an hour, but lasts only 150 femtoseconds.
The team is currently exploring the use of their gas pedal for a variety of purposes, such as testing the ability of space electronics to withstand radiation, photographing the 3D internals of chip designs, and even developing new cancer therapies and advanced medical imaging techniques.
The gas pedal could also be used to power an X-ray free-electron laser, a device that can take slow-motion movies of atomic- or molecular-scale events such as drug-cell interactions, changes inside a battery that cause a fire to start, chemical reactions inside a solar panel, and the way that viral proteins change shape as they infect a cell.