Particle accelerators have long been used for a variety of applications, including semiconductor research, medical imaging and therapies, and material and energy research. However, traditional particle accelerators are massive structures that require kilometers of space, making them expensive to build and limiting their availability to only a few national laboratories and universities.
In an exciting development, researchers from the University of Texas at Austin, in collaboration with several national laboratories, European universities, and TAU Systems Inc., have achieved a major breakthrough in accelerator technology. They have successfully demonstrated a compact particle accelerator that is less than 20 meters long but capable of producing an electron beam with an energy of 10 billion electron volts (10 GeV). This achievement is remarkable considering that there are currently only two other accelerators operating in the United States that can reach such high electronic energies, both of which are approximately 3 kilometers long.
The compact accelerator, known as the advanced wakefield laser accelerator, opens up new possibilities for various scientific applications. The team led by Bjorn “Manuel” Hegelich at UT Austin is exploring the use of this accelerator for testing space electronics’ resilience to radiation, imaging 3D internal structures of semiconductor chip designs, developing cancer therapies and advanced medical imaging techniques.
Moreover, this type of accelerator has the potential to power another device called an X-ray free electron laser. This could enable scientists to capture slow-motion movies of atomic or molecular processes such as drug interactions with cells, changes within batteries that could lead to fires, chemical reactions within solar panels, and viral proteins changing shape upon infecting cells.
The concept behind Wakefield laser accelerators was first described in 1979. It involves using an extremely powerful laser to impact helium gas and create plasma waves that eject electrons from the gas in a high-energy electron beam. Over the past few decades, several research groups have developed more powerful versions of this technology. The key advance made by Hegelich’s team is based on nanoparticles – an auxiliary laser hits a metal plate inside the gas cell to inject metal nanoparticles into the plasma wave. These nanoparticles significantly increase the energy delivered to the electrons by the waves.
Hegelich describes this process using an analogy: “It’s like surfers riding plasma waves created by our boat sailing across a lake.” The introduction of nanoparticles ensures that more electrons can be directed into the wave at specific times and locations rather than being distributed statistically throughout the interaction.
For their experiment, researchers used one of the most powerful pulsed lasers in the world –the Texas Petawatt Laser located at UT Austin– which fires ultra-intense pulses every hour. Their long-term goal is to develop a table-sized laser capable of firing thousands of times per second so as to make their entire accelerator much more compact and usable in larger environments than conventional accelerators.
The study was co-authored by Constantin Aniculaesei (now at Heinrich Heine University) and Thanh Ha (a doctoral student at UT), among others. Hegelich’s laboratory also birthed TAU Systems Inc., which holds an exclusive license from UT for their fundamental patent related to generating nanoparticles in a gas cell.
This groundbreaking research was supported by various organizations including US Air Force Office of Scientific Research, US Department of Energy UK Engineering & Physical Sciences Research Council Horizon 2020 program funded by European Union
According to sourcethese findings represent a significant step forward towards realizing compact particle accelerators with immense potential for various scientific applications.