Navigation Links
Plasma as a fast optical switch
Date:11/8/2010

Just like an electrical switch allows the flow of electricity into electrical circuits, relativistic transparency in plasma can act like a fast optical switch allowing the flow of light through otherwise opaque plasma. Modern day lasers, such as the Trident laser in Los Alamos National Laboratory delivers a 200 terawatt power pulse (roughly 400 times the average electrical consumption of the United States) in half a trillionth of a second (picosecond) time. As shown in Fig. 1, when the laser power reaches a threshold limit, relativistic transparency in plasma turns the initially opaque plasma transparent in less than a tenth of a picosecond.

Powerful lasers are used to drive plasmas in next-generation particle accelerators and x-ray beams. One shortcoming of these beams is that they typically have a range of energy, caused by the gradual rise of laser power from zero to its maximum level. Using an optical switch, this ramp up time can be reduced to less than a tenth of a picosecond, delivering peak laser power to the plasma on a faster time scale.

So, how does this relativistic transparency happen inside plasma? When a laser beam is incident on (or strikes) plasma, electrons in the plasma react to the laser to cancel its presence inside the plasma. But when the laser is powerful enough to accelerate electrons close to the speed of light, the mass of the electrons increases, making them "heavier." These heavier electrons cannot react quickly enough; hence the laser beam propagates through the plasma.

Now, for the first time, scientists at Los Alamos National Laboratory and Ludwig-Maximilian Universitt (LMU) in Germany have been able to make a direct observation of relativistic transparency in thin plasmas using a Frequency-Resolved Optical Gating (FROG) device. The discovery was made possible by two key capabilities: the ability to fabricate carbon foils a few nanometers thick to produce thin plasma, and the elimination of optical noise preceding the Trident laser pulse on a few picosecond timescale.

Initially, the researchers observed pulse shortening due to relativistic transparency and consistent spectral broadening. Later, they also measured the shape of the laser pulses incident on and transmitted through the plasma to directly observe the transparency as shown in figure 2. The transmitted laser pulse is roughly half the duration of the incident laser pulse, with a transparency turn on time around a fifth of a picosecond. The experimental results are well consistent with that of computer simulation, except the loss of fast turn-on time due to propagation effects arising from diffraction. Efforts are currently underway to eliminate diffraction limitations to observe the true turn-on time.


'/>"/>

Contact: Saralyn Stewart
stewart@physics.utexas.edu
512-694-2320
American Physical Society
Source:Eurekalert

Related medicine news :

1. Restrictions on female plasma may not be warranted
2. Restrictions on Plasma From Female Donors May Need Revisiting
3. Inappropriate uses of frozen plasma
4. New York Sports Medicine Offers Platelet Rich Plasma Therapy For Treatment of Injury
5. After Teeth Are Pulled, Platelet-Rich Plasma May Speed Healing
6. Plasma protein appears to be associated with development and severity of Alzheimers disease
7. Researcher find fats galore in human plasma
8. Transitions Optical Partners With Dr. Aliza Through VidaySalud.com to Improve Visual Quality for Hispanics
9. First Virtual Optical Store Serves Military Personnel
10. Shamir Optical Industry Reports Fourth Quarter and Year-End 2009 Results
11. Mass. General Hospital to create registry for coronary optical coherence tomography
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/8/2016)... ... 2016 , ... The Compretta Insurance Agency, a family owned insurance and financial ... Hancock County area, is announcing the launch of a charity effort aimed at raising ... Food Pantry has worked for more than 30 years to meet the food needs ...
(Date:12/7/2016)... ... December 07, 2016 , ... DrugDev again demonstrated its ... is one of the early adopters completing EU-U.S. Privacy Shield Certification from the U.S. ... companies on both sides of the Atlantic with a mechanism to comply with EU ...
(Date:12/7/2016)... Kenosha, Wisconsin (PRWEB) , ... December 07, 2016 , ... ... the extraordinary new MedMaster™ MPCNGX . The MPCNGX is a multi-function, sealed, LED ... the right amount of light where and when it’s needed. , A ...
(Date:12/7/2016)... ... December 07, 2016 , ... Wavelink, an industry ... Control through a new partnership with Splashtop Inc. This remote control for Android ... to help businesses maximize their uptime and productivity. , Wavelink offers powerful enterprise ...
(Date:12/7/2016)... ... December 07, 2016 , ... In the early morning of October 30, ... medical call when he lost control of his patrol car. The vehicle overturned into ... he was transported to Atlanta Medical Center, where he later succumbed to his injuries. ...
Breaking Medicine News(10 mins):
(Date:12/8/2016)... , Dec. 8, 2016  EIP Pharma, LLC ... obtained proof-of-mechanism for neflamapimod (previously code named VX-745), ... 2a clinical trials that demonstrated significant Alzheimer,s disease ... (12-week treatment) and Study 303 (6-week treatment) are ... in Alzheimer,s Disease (CTAD) scientific conference in ...
(Date:12/8/2016)... 2016 Dignitana, a world leader in medical ... Technology, creator of the award-winning, patented Boa® system, to ... the DigniCap® scalp cooling system. DigniCap® was cleared by ... and is the first medical scalp cooling device to ... system features a patented tight-fitting silicone cooling cap that ...
(Date:12/8/2016)... SAN DIEGO , Dec. 8, 2016 /PRNewswire/ ... dedicated to improving cancer patient care from diagnosis ... the company,s recently completed Phase 1b study in ... at the San Antonio Breast Cancer Symposium. ... Cancer Center at UC San Diego Health, delivered ...
Breaking Medicine Technology: