- Researchers are planning to develop 100 petawatts laser that can rip apart empty space to produce antimatter and matter.
- It can target spot targets with a precision of 3 micrometers.
- It’s a demonstration of new methods to accelerate particles for use in high-energy physics and medicine.
Chinese Physicists are working on a laser technique that can produce the most powerful light pulses the world has ever witnessed. The ultimate goal is to develop 100 petawatts (million billion watts) laser that is capable enough to rip apart vacuum to produce antimatter and matter.
The laser, named Shanghai Superintense Ultrafast Laser Facility (SULF), is made of titanium-doped sapphire in a small cylindrical structure. The system distills light into pulses of astonishing power after kindling it in the crystal shunting it through a setup of mirrors and lenses.
These powerful pulses could target precise spots measuring 3 micrometers across, which is about 2,000 times less than the thickness of a pencil. They have already created a laser that can produce 5.3 petawatts of power. The intensity of light doesn’t reduce each time the laser fires. However, they last for a very short duration – less than a trillionth of a second.
Ambitions
Now the team is enhancing their laser to beat their own record by the end of 2018 with 10 petawatts. To put that into context, it would have over 1,000 times the power of all electrical grids in the world combined.
The plan doesn’t end here. Soon, they will start developing a 100 petawatts laser called Station of Extreme Light (SEL). By the end of 2023 (as planned), the laser could generate powerful pulses into a 20 meters underground chamber, subjecting targets to enormous pressure and temperature.
Utilization
Now coming to the most important question – how this will be helpful. It would be capable enough to tear electrons as well as their antimatter counterparts, positrons in vacuum (also referred as “breaking the vacuum”).
Laser in Shanghai sets a new record in power | Credit: Kan Zhan
It’s a demonstration of new methods to accelerate particles for use in high-energy physics and medicine. It would also strike illustration that energy and matter are interchangeable, as one of the most famous equations in physics E=mc2 states. Although nuclear weapons convert matter into massive amounts of light and heat, the reverse conversion is not an easy task.
Reference: Sciencemag | doi:10.1126/science.aat0939
Competition
In coming years, 10 petawatts instruments should switch on in the Czech Republic and Romania as part of Extreme Light Infrastructure in Europe. Recently, the project revealed its ambitions for developing a 100-petawatts-scale instrument.
In fact, Russian physicists came up with a blueprint of 180 petawatts laser called Exawatt Center for Extreme Light Studies (XCELS), while scientists in Japan have proposed a 30 petawatts device.
University of Rochester in New York is also planning to build a 75 petawatts device, known as Optical Parametric Amplifier Line (OPAL). It would utilize the most powerful lasers in the country, OMEGA-EP.
Achieving Higher Powers
One of the best ways to reach higher powers is to pack the pulse energy into shorter durations. This can be done by intensifying the light in titanium-doped sapphire crystals. These pulses bounce back and forth in a mirrored laser chamber.
By configuring the setup, one can make individual frequency components to cancel each other out over most of their pulse-length, while strengthening each other in a very short (femtoseconds) fleeting pulse. Integrating those pulses with an additional energy of a few hundred joules, a maximum of 10 petawatts of power can be obtained.
The overall setup can be installed in a large room under tens of millions of dollars, compared to $3.5 billion National Ignition Facility’s system that generates only 1 petawatt pulses, but for longer durations.
Increasing the power of pulse by another magnitude order, from 10 petawatts to 100 petawatts would require more efforts. A simple way is to raise the energy of the pulse from hundred-order joules to thousand-order joules. However, there is one big problem, i.e. the titanium-doped sapphire cannot support such energies.
Therefore, the researchers have diverted their focus to parametric amplifiers, which transmit the pulse (from optical grating) into an artificial nonlinear crystal. If you re-compress the resulting powerful pulse, you would be able to generate more energy.
Read: An UltraThin Mirror Whose Reflectivity Can Be Controlled With Voltage
In the future, high-repetition petawatt pulses accelerating electrons could cut the cost of machine – successor of the Large Hadron Collider, a 30-Km-long electron-positron collider. Moreover, a system based on 100 petawatts could be 10 times cheaper and shorter than the current $10 billion machine.
