Featured Research

from universities, journals, and other organizations

Smaller accelerators for particle physics?

Date:
May 27, 2014
Source:
American Institute of Physics
Summary:
It took every inch of the Large Hadron Collider's 17-mile length to accelerate particles to energies high enough to discover the Higgs boson. Now, imagine an accelerator that could do the same thing in, say, the length of a football field. Or less. That is the promise of laser-plasma accelerators. Scientists have grappled with building these devices for two decades, and a new theoretical study predicts that this may be easier than previously thought.

Snapshots of the laser energy density at the beginning of the simulation for the array of laser pulse (left plot), and after some propagation distance of the beamlets in the plasma (right plot), where the laser field exhibits a clear incoherent pattern.
Credit: Carlo Benedetti/LBL

It took every inch of the Large Hadron Collider's 17-mile length to accelerate particles to energies high enough to discover the Higgs boson. Now, imagine an accelerator that could do the same thing in, say, the length of a football field. Or less.

That is the promise of laser-plasma accelerators, which use lasers instead of high-power radio-frequency waves to energize electrons in very short distances. Scientists have grappled with building these devices for two decades, and a new theoretical study predicts that this may be easier than previously thought.

The authors are Carlo Benedetti, Carl Schroeder, Eric Esarey, and Wim Leemans, physicists at Lawrence Berkeley National Laboratory's Berkeley Lab Laser Accelerator (BELLA) Center. Their paper, "Plasma wakefields driven by an incoherent combination of laser pulses: A path towards high-average power laser-plasma accelerators," appears in the May Special Issue of Physics of Plasmas, from AIP Publishing.

If their models prove correct, they could help lower the cost of high-energy physics research -- the Large Hadron Collider cost $9 billion -- as well as many other industrial and medical applications of accelerators.

Laser-plasma accelerators work by blasting a powerful laser beam into a plasma, a cloud of unattached electrons and ions.

"The effect is like the wake of boat speeding down a lake. If the wake was big enough, a surfer could ride it," Leemans, who heads the BELLA Center, explained.

"Imagine that the plasma is the lake and the laser is the motorboat. When the laser plows through the plasma, the pressure created by its photons pushes the electrons out of the way. They wind up surfing the wake, or wakefield, created by the laser as it moves down the accelerator," he said.

The fast moving electrons leave the heavy ions behind. As they separate, they create gigantic electric fields, 100 to 1,000 times larger than those in conventional accelerators.

This is how they accelerate electrons so rapidly. For example, Stanford's Linear Accelerator Center takes two miles to drive an electron to 50 billion electron volts (GeV). Leemans' experimental laser-plasma accelerator takes electrons to more than 1 GeV in slightly more than 1 inch.

It takes a lot of laser power to generate a wakefield. For example, BELLA's petawatt (1 quadrillion watts) laser has a 10 meter x 10 meter footprint. It generates 400 times more power than all the world's power plants combined, though only for 40 femtoseconds (40 quadrillionths of a second).

Unfortunately, it takes BELLA's laser a full second to recharge and send a second pulse. High-energy physics research requires tens of thousands of pulses per second. Many other applications would benefit from multiple pulses per second.

BELLA's laser has the highest repetition rate of any petawatt laser in the world. Building a faster petawatt laser would require a heroic feat of engineering.

Several European researchers have suggested using an array of smaller lasers to produce one enormous pulse. Since less powerful lasers recharge faster, they could produce hundreds or even thousands of pulses per second and sustain a wakefield over many meters.

The hurdle they needed to overcome was how to synchronize hundreds of lasers so they all pulsed within less than a femtosecond of one another.

Such precision would be expensive and presents serious technical problems. But the concept of combining lasers got Leemans' team thinking.

What if the beam was not perfect? What if it were just good enough to rapidly raise the photon pressure on the electrons? Could we get away with it, they wondered.

According to the model presented in Physics of Plasmas, they could. Leemans compares it to pushing a swing.

"Instead of one big push, we would give it many smaller pushes at roughly the same time. It's not quite perfect, but the swing doesn't really care. It averages over all these little pushes and up it goes."

Laxer timing would make larger and more sustainable accelerators practical. Leemans hopes to power them with a new technology based on highly-efficient fiber lasers. The power that off-the-shelf welding lasers offer demonstrates multi-kW capabilities but much work is needed to pack the power into ultrashort pulses needed for laser plasma accelerators. The paper offers an approach that gets us a step closer.

The new accelerators would offer new options to physicists trying to unravel how the universe is put together. It could lower the cost of industrial uses, and make high-energy accelerators more affordable for hospitals.

Just think of it as dreaming big by thinking small.


Story Source:

The above story is based on materials provided by American Institute of Physics. The original article was written by Jason Bardi. Note: Materials may be edited for content and length.


Journal Reference:

  1. C. Benedetti, C. B. Schroeder, E. Esarey, and W. P. Leemans. Plasma wakefields driven by an incoherent combination of laser pulses: a path towards high-average power laser-plasma accelerators. Physics of Plasmas, May 27, 2014 DOI: 10.1063/1.4878620

Cite This Page:

American Institute of Physics. "Smaller accelerators for particle physics?." ScienceDaily. ScienceDaily, 27 May 2014. <www.sciencedaily.com/releases/2014/05/140527114302.htm>.
American Institute of Physics. (2014, May 27). Smaller accelerators for particle physics?. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2014/05/140527114302.htm
American Institute of Physics. "Smaller accelerators for particle physics?." ScienceDaily. www.sciencedaily.com/releases/2014/05/140527114302.htm (accessed July 28, 2014).

Share This




More Matter & Energy News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

More Coverage


A Path Toward More Powerful Tabletop Accelerators

May 28, 2014 Making a tabletop particle accelerator just got easier. A new study shows that certain requirements for the lasers used in an emerging type of small-area particle accelerator can be significantly ... read more
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins