Featured Research

from universities, journals, and other organizations

A path toward more powerful tabletop accelerators

Date:
May 28, 2014
Source:
DOE/Lawrence Berkeley National Laboratory
Summary:
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 relaxed. Researchers hope the finding could bring about a new era of accelerators that would need just a few meters to bring particles to great speeds, rather than the many kilometers required of traditional accelerators.

3D Map of the longitudinal wakefield generated by the incoherent combination of 208 low-energy laser beamlets. In the region behind the driver, the wakefield is regular.
Credit: Carlo Benedetti, Berkeley Lab

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 relaxed. Researchers hope the finding could bring about a new era of accelerators that would need just a few meters to bring particles to great speeds, rather than the many kilometers required of traditional accelerators. The research, from scientists at the U.S. Department of Energy's (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab), is presented as the cover story in the May special issue of Physics of Plasmas.

Traditional accelerators, like the Large Hadron Collider where the Higgs boson was recently discovered, rely on high-power radio-frequency waves to energize electrons. The new type of accelerator, known as a laser-plasma accelerator, uses pulses of laser light that blast through a soup of charged particles known as a plasma; the resulting plasma motion, which resemble waves in water, accelerates electrons riding atop the waves to high speeds.

3D Map of the longitudinal wakefield generated by the incoherent combination of 208 low-energy laser beamlets. In the region behind the driver, the wakefield is regular. Credit: Carlo Benedetti, Berkeley Lab

The problem, however, is creating a laser pulse that's powerful enough to compete with the big accelerators. In particular, lasers need to have the capability to fire a high-energy pulse thousands of times a second. Today's lasers can only manage one pulse per second at the needed energy levels.

"If you want to make a device that's of use for particle physics, of use for medical applications, of use for light source applications, you need repetition rate," explains Wim Leemans, physicist at Berkeley Lab. In January of 2013, the DOE held a workshop on laser technology for accelerators. At the time, says Leemans, the big question was how to get from the current technology to the scaled up version.

Conventional wisdom holds that many smaller lasers, combined in a particular way, could essentially create one ultra powerful pulse. In theory, this sounds fine, but the practical requirements to build such a system have seemed daunting. For instance, it was believed that the light from the smaller lasers would need to be precisely matched in color, phase, and other properties in order to produce the electron-accelerating motion within the plasma. "We thought this was really challenging," says Leemans, "We thought, you need this nice laser pulse, and everything needs to be done properly to control the laser pulse."

But the new Berkeley Lab study has found this isn't the case. Paper co-authors Carlo Benedetti, Carl Schroeder, Eric Esarey and Leemans wanted to see what an erratic laser pulse would actually do inside a plasma. Guided by theory and using computer simulations to test various scenarios, the researchers looked at how beams of various colors and phases -- basically a hodgepodge of laser light -- affected the plasma. They soon discovered, no matter the beam, the plasma didn't care.

"The plasma is a medium that responds to a laser, but it doesn't respond immediately," says Benedetti, a physicist at Berkeley Lab. The light is just operating on a faster time scale and a smaller length scale, he explains. All of the various interference patterns and various electromagnetic fields average out in the slow-responding plasma medium. In other words, once laser light gets inside the plasma, many of the problems disappear.

"As an experimentalist for all these years we're trying to make these perfect laser pulses, and maybe we didn't need to worry so much," says Leemans. "I think this will have a big impact on the laser community and laser builders because all of a sudden, they'll think of approaches where before hand all of us said, 'No, no, no. You can't do that.' This new result says, well maybe you don't have to be all that careful."

Leemans says the ball is back in the experimentalists' and laser builders' court to prove that the idea can work. In 2006, he and his team demonstrated a three-centimeter long plasma accelerator. Where a traditional accelerator can take kilometers to drive an electron to 50 giga-electron volts (GeV), Leemans and team showed that a mini-laser plasma accelerator could get electrons to 1 GeV in just three centimeters with a laser pulse of about 40 terawatt. To go to higher electron energies, in 2012, a larger more powerful laser was installed at the Berkeley Lab Laser Accelerator (BELLA) facility with a petawatt pulse (1 quadrillion watts) that lasts 40 femtoseconds, which is now being used in experiments that aim at generating a 10 GeV beam.

Still, the goal of a high-repetition rate, 10-GeV laser-plasma accelerator that fires a thousand pulses or more per second, is at least five to ten years away, says Leemans. But a new project called k-BELLA (k is for kilohertz) is in the works that will use the principles of combined, messy laser light sources to produce fast, more powerful laser pulses. "Once we synthesize a pulse at higher repetition rates," says Leemans, "we will be on our way towards a kilohertz GeV laser plasma accelerator."

This work was supported by the DOE Office of Science and used the facilities of the National Energy Research Scientific Computing Center (NERSC) located at Berkeley Lab.


Story Source:

The above story is based on materials provided by DOE/Lawrence Berkeley National Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. C. Benedetti, C. B. Schroeder, E. Esarey, W. P. Leemans. Plasma wakefields driven by an incoherent combination of laser pulses: A path towards high-average power laser-plasma acceleratorsa). Physics of Plasmas, 2014; 21 (5): 056706 DOI: 10.1063/1.4878620

Cite This Page:

DOE/Lawrence Berkeley National Laboratory. "A path toward more powerful tabletop accelerators." ScienceDaily. ScienceDaily, 28 May 2014. <www.sciencedaily.com/releases/2014/05/140528133153.htm>.
DOE/Lawrence Berkeley National Laboratory. (2014, May 28). A path toward more powerful tabletop accelerators. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2014/05/140528133153.htm
DOE/Lawrence Berkeley National Laboratory. "A path toward more powerful tabletop accelerators." ScienceDaily. www.sciencedaily.com/releases/2014/05/140528133153.htm (accessed July 23, 2014).

Share This




More Matter & Energy News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. 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


Smaller Accelerators for Particle Physics?

May 27, 2014 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 ... 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