Berkeley Lab's particle accelerator set a new record

Researchers at the Lawrence Berkeley National Laboratory of the US Department of Energy have just announced that they have found a way to accelerate subatomic particles to the highest known energy level ever. for a small accelerator. By using a laser to bombard hot plasma in a desktop-plasma laser accelerator , the scientists created accelerated energy to 4.25 giga-electron volts (GeV).

Take, for example, the Large Hardon Collider (LHC) particle accelerator at CERN, which has a circumference of 27km and accelerates the particle by sequentially modulating electromagnetic fields in a metal cavity. This condition allows acceleration to an energy level of about 100 MeV / m before exceeding the safety threshold and the metal cavity can be destroyed. Compared to the Berkeley lab table accelerator, it set a world record when accelerating electrons inside a plasma-containing tube only 9cm long to the speed that a conventional particle accelerator would It takes a lot of miles to reach the same speed.

However, to be fair, we need to understand that laser-plasma accelerators use a different acceleration method than traditional accelerators to achieve extremely high energy levels. In this case, the experiment was done with the help of one of the world's most powerful lasers called BELLA (Berkeley Lab Laser Accelerator) . This laser system produces a beam of light equivalent to 1 million million (10 ^ 15) Watt (1 Petawatt) and is used by Berkeley researchers in very small tubes containing plasma of particle accelerators. . However, in this initial experiment, the laser beam was limited to a capacity of 300,000 Gigawatt.

Computer model of wakefield acceleration region of plasma along the channel length (9cm distance).

Laser systems currently used for other laser-plasma particle accelerators, such as Stanford's SLAC system can only produce a fraction of the capacity compared to BELLA (about 1 Terawatt) to create 300 MeV acceleration energy. Thereby it is possible to see the enormous energy that the new Berkeley Lab system can create when used in a potential part of the system.

Dr Wim Leemans, director of accelerator and application technology at Berkeley, said: "This result requires the ability to control laser and plasma beam sophistication, which is what we did when Forcing this laser beam into a small hole of only 500 microns in diameter, which is 14 meters away, the BELLA laser system gives the beam a high enough and stable performance so that we can use it for experiments. "

When activated, the laser energy from the BELLA shoots into a channel through the plasma and creates many waves of capture energy and accelerates free electrons in the plasma environment to a higher energy state. Researchers compared this process like when a surfer uses a speeding board from the top of a wave and glides down to the sea.

However, from the electron aspect, of course, they do not have any "boards" , waves (here are energy waves) that collide at millions of miles per hour and wave height for the main electron. is a plasma idea. Proportional to the size of the electron, this wall is thousands of feet tall.

When conducting high energy experiments, the researchers also determined that the success rate would be very low and with a small deviation calculation, the result could be a disaster. They looked for ways to model many parameters and test hypotheses to be ready for possible effects when experimenting in practice. And finally, the research team asked the help of the National Energy Research Scientific Computing Center (NERSC) to perform simulation work on computers before conducting a real experiment.

"The smallest changes in setup can also create a disturbance. We are aiming for many operating conditions and the best methods to control the accelerator," Eric Esarey - scientific advisor for the Berkeley Lab, leader of the hypothetical development team.

Dr. Leemans believes that the team's future work will require the creation and approval of a new technique for shaping and controlling plasma channels. More specifically, the team's goal is to create an accelerating energy equivalent to 10 GeV, more than double the current milestone. To accelerate electrons to such an enormous energy level, the researchers will need to ensure more precise control of the plasma density contained in the tube, where the laser beam will pass.

The results of the study were published in Physical Review Letters.

Reference: Berkeley Lab.