Scientists create tiny particle accelerator on a chip.

Researchers from Friedrich-Alexander University (FAU) have successfully accelerated electrons using a nanodevice, marking a significant step toward an accelerator on a chip. This development could lead to smaller, less expensive particle accelerators, crucial tools in various sectors, including industry, research, and medicine. The team used a method known as dielectric laser acceleration, or nanophotonic acceleration, to speed up the electrons within a photonic nanostructure. The structures used are as small as a computer chip, with the channel the electrons are accelerated through being only roughly 225 nanometers in width.

The researchers aim to increase the energy gain and electron current to a level that would make the particle accelerator on a chip sufficient for medical applications, such as administering radiotherapy directly at the affected area within the body. This breakthrough was achieved almost simultaneously by a team at Stanford University in the United States. Both teams are part of a project funded by the Gordon and Betty Moore Foundation, aimed at realizing the “Accelerator on a chip”.

Researchers at Friedrich-Alexander University (FAU) and Stanford University have successfully accelerated electrons using a nanodevice, marking a significant step towards creating a particle accelerator on a chip. The team, led by Prof. Dr. Peter Hommelhoff and including Dr. Tomáš Chlouba, Dr. Roy Shiloh, Stefanie Kraus, Leon Brückner, and Julian Litzel, used lasers to accelerate electrons within a photonic nanostructure. This could potentially reduce the size and cost of particle accelerators, which are crucial in industry, research, and medicine. The findings were published in the journal “Nature”. The project was funded by the Gordon and Betty Moore Foundation.

Breakthrough in Electron Acceleration Using Nanodevices

For the first time, researchers from Friedrich-Alexander University (FAU) have successfully accelerated electrons using a nanodevice. Particle accelerators are essential tools in various sectors, including industry, research, and medicine. However, these machines often require significant space, ranging from a few square meters to large research centres. The use of lasers to accelerate electrons within a photonic nanostructure presents a microscopic alternative that could potentially reduce costs and make devices less bulky. Until now, no substantial energy gains were demonstrated, but the FAU team has now successfully demonstrated the first nanophotonic electron accelerator.

The Potential of Nanophotonic Accelerators

When people think of particle accelerators, they often envision large structures like the Large Hadron Collider in Geneva. However, these huge particle accelerators are not the norm. More commonly, we encounter them in medical imaging procedures or during radiation to treat tumours. Even then, the devices are several meters in size and rather bulky. To improve and decrease the size of existing devices, physicists worldwide are working on dielectric laser acceleration, also known as nanophotonic accelerators. These structures are only 0.5 millimeters in length, and the channel through which the electrons are accelerated is roughly 225 nanometers in width, making these accelerators as small as a computer chip.

The Dream Application of Nanophotonic Accelerators

The ultimate goal would be to place a particle accelerator on an endoscope to administer radiotherapy directly at the affected area within the body. This dream may still be far beyond the reach of the FAU team, but they have now taken a significant step in the right direction by demonstrating the nanophotonic electron accelerator. For the first time, we can speak about a particle accelerator on a chip.

The Process of Accelerating Particles

Just over two years ago, the team made their first major breakthrough: they succeeded in using the alternating phase focusing (APF) method to control the flow of electrons in a vacuum channel over long distances. This was the first major step towards building a particle accelerator. Now, all that was needed to gain major amounts of energy was acceleration. Using this technique, they have now succeeded not only in guiding electrons but also in accelerating them in these nano-fabricated structures over a length of half a millimeter. This might not sound like much of an achievement to many, but it is a huge success for the field of accelerator physics.

The Future of Nanophotonic Accelerators

This demonstration is just the beginning. The aim now is to increase the gain in energy and electron current to such an extent that the particle accelerator on a chip is sufficient for applications in medicine. For this to be the case, the gain in energy would have to be increased by a factor of approximately 100. To achieve higher electron currents at higher energies at the output of the structure, the structures will have to be expanded or several channels placed next to each other. This is the next step for the FAU laser physicists.

Summary

“Researchers have successfully accelerated electrons using a nano device, marking a significant step towards creating a particle accelerator on a chip. This breakthrough could lead to more compact and cost-effective particle accelerators, potentially revolutionising applications in medicine, industry, and research.”

• Researchers from Friedrich-Alexander University (FAU) and Stanford University have successfully accelerated electrons using a nanophotonic device, marking a significant step towards creating a particle accelerator on a chip.
• Particle accelerators, typically large and costly, are crucial in various sectors including industry, research, and medicine. The new nanophotonic accelerator could potentially reduce costs and size of these devices.
• The FAU team, led by Prof. Dr. Peter Hommelhoff and including Dr. Tomáš Chlouba, Dr. Roy Shiloh, Stefanie Kraus, Leon Brückner and Julian Litzel, used ultrashort laser pulses to accelerate particles in nanostructures.
• The team managed to gain energy of 12 kiloelectron volts, a 43% increase, over a length of half a millimeter. This is a significant achievement in the field of accelerator physics.
• The ultimate goal is to increase the energy gain and electron current to a level that would make the particle accelerator on a chip viable for medical applications. This would require an energy gain increase by a factor of approximately 100.
• The research was funded by the Gordon and Betty Moore Foundation and the findings were published in the journal “Nature”.