Featured Research

from universities, journals, and other organizations

Laser heating: New light cast on electrons heated to several billion degrees

Date:
December 5, 2011
Source:
Helmholtz Association of German Research Centres
Summary:
A new class of high power lasers can effectively accelerate particles like electrons and ions with very intense, short laser pulses. Physicists have developed a new theoretical model for predicting the density and temperature of hot electrons which surpasses existing models in accurately describing experimental results and simulations.

When a very intense laser pulse hits ion electron plasma (ions: orange, electrons: blue), electrons are heated to a couple of billion degrees. This initiates an explosive expansion of plasma ions which are then accelerated to very high energies. The distribution of the electron temperature during radiation bombardment is depicted in the background.
Credit: Image courtesy of Helmholtz Association of German Research Centres

A new class of high power lasers can effectively accelerate particles like electrons and ions with very intense, short laser pulses. This has attracted the interest of researchers around the globe, working out the details of the acceleration process which occurs when a laser beam impinges on a thin foil to accelerate ions from the foil's rear surface to high energies. The electrons in the foil are heated by the laser pulse, thereby gaining energy. These electrons in turn give part of their energy to the ions, thereby converting laser pulse energy to ion energy.

Physicists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) have developed a new theoretical model for predicting the density and temperature of these hot electrons which surpasses existing models in accurately describing experimental results and simulations.

Particle acceleration by short, intense pulses of light is a modern technology which exhibits considerable advantages over conventional techniques: The distance needed for acceleration is much shorter and the costs for such systems are potentially much lower. The potentials of the new ion acceleration technology will be explored by a laser system which is currently under construction for use at the University Hospital in Dresden. It will be jointly used by the partners HZDR, the University Hospital, and TU Dresden for cancer research and therapy. For the first time ever, a prototype high performance laser will be used in addition to a conventional ion accelerator for radiation tumor therapy.

High power lasers like the DRACO laser at the Helmholtz-Zentrum Dresden-Rossendorf are about ten to a hundred times more intense than their predecessors for which theoretical estimates of electron temperature and density were more or less accurate. For the new generation of lasers, though, experimental findings considerably differ from predictions. Thomas Kluge, physicist in the Laser Particle Acceleration Division at the HZDR, together with his colleagues has developed a new theoretical model of laser electron interaction. Hot electrons serve as intermediaries in laser ion acceleration by transferring energy from the laser to the ions. Hence, precise information on the energy of hot electrons is vital for future laser-driven cancer therapy facilities.

Existing models have not been able to accurately predict the properties of hot electrons specifically at very high intensity -- like the electrons generated by the high power laser DRACO and the petawatt laser PENELOPE which is currently under construction at the HZDR. The Dresden researchers have developed an equation that allows precisely calculating the hot electron energy by taking into account the distribution of laser accelerated electrons as well as their dynamics according to the theory of special relativity.

"These new insights surpass models that have been around for decades; thus, permitting, on the one hand, an explanation of previous measurements while, on the other hand, allowing for predicting and optimizing future experiments with great precision," notes Michael Bussmann, Head of the HZDR's Junior Research Group "Computational Radiation Physics." The results were published in the scientific journal Physical Review Letters and are currently being applied to additional acceleration scenarios by the Dresden researchers in order to permit the future use of laser accelerators for medical use.


Story Source:

The above story is based on materials provided by Helmholtz Association of German Research Centres. Note: Materials may be edited for content and length.


Journal Reference:

  1. T. Kluge, T. Cowan, A. Debus, U. Schramm, K. Zeil, M. Bussmann. Electron Temperature Scaling in Laser Interaction with Solids. Physical Review Letters, 2011; 107 (20) DOI: 10.1103/PhysRevLett.107.205003

Cite This Page:

Helmholtz Association of German Research Centres. "Laser heating: New light cast on electrons heated to several billion degrees." ScienceDaily. ScienceDaily, 5 December 2011. <www.sciencedaily.com/releases/2011/11/111121104054.htm>.
Helmholtz Association of German Research Centres. (2011, December 5). Laser heating: New light cast on electrons heated to several billion degrees. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2011/11/111121104054.htm
Helmholtz Association of German Research Centres. "Laser heating: New light cast on electrons heated to several billion degrees." ScienceDaily. www.sciencedaily.com/releases/2011/11/111121104054.htm (accessed July 22, 2014).

Share This




More Matter & Energy News

Tuesday, July 22, 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:
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