Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Paving the way: an accelerator on a microchip

26.11.2018

Electrical engineers in the accelerator physics group at TU Darmstadt have developed a design for a laser-driven electron accelerator so small it could be produced on a silicon chip. It would be inexpensive and with multiple applications. The design, which has been published in Physical Review Letters, is now being realised as part of an international collaboration.

Particle accelerators are usually large and costly, but that will soon change if researchers have their way. The Accelerator on a Chip International Program (AChIP), funded by the Gordon and Betty Moore Foundation in the U.S., aims to create an electron accelerator on a silicon chip.


Accelerator chip on the tip of a finger, and an electron microscope image of the chip.

Hagen Schmidt / Andrew Ceballos

The fundamental idea is to replace accelerator parts made of metal with glass or silicon, and to use a laser instead of a microwave generator as an energy source.

Due to glass’s higher electric field load capacity, the acceleration rate can be increased and thus the same amount of energy can be transmitted to the particles within a shorter space, making the accelerator shorter by a factor of approximately 10 than traditional accelerators delivering the same energy.

One of the challenges here is that the vacuum channel for the electrons on a chip has to be made very small, which requires that the electron beam is extremely focused. The magnetic focusing channels used in conventional accelerators are much too weak for this. This means that an entirely new focusing method has to be developed if the accelerator on a chip is to become reality.

As part of TU Darmstadt’s Matter and Radiation Science profile area, the AChIP group in accelerator physics (Department of Electrical Engineering and Information Technology at TU Darmstadt), led by the junior scientist Dr. Uwe Niedermayer, recently proposed a decisive solution which calls for using the laser fields themselves to focus the electrons in a channel only 420 nanometres wide.

The concept is based on abrupt changes to the phase of the electrons relative to the laser, resulting in alternating focusing and de-focusing in the two directions in the plane of the chip surface. This creates stability in both directions.

The concept can be compared to a ball on a saddle – the ball will fall down, regardless of the direction in which the saddle tilts. However, turning the saddle continuously means the ball will remain stable on the saddle. The electrons in the channel on the chip do the same.

Perpendicular to the chip’s surface, weaker focusing is sufficient, and a single quadrupole magnet encompassing the entire chip can be used. This concept is similar to that of a conventional linear accelerator. However, for an accelerator on a chip, the electron dynamics have been changed to create a two-dimensional design which can be realised using lithographic techniques from the semiconductor industry.

Niedermayer is currently a visiting scientist at Stanford University; the American university is leading the AChIP programme along with University of Erlangen in Germany. At Stanford, he is collaborating with other AChIP scientists with the aim of creating an accelerator on a chip in an experimental chamber the size of a shoebox.

A commercially available system, adapted by means of complicated non-linear optics, is used as a laser source. The aim of the AChIP programme, which has funding until 2020, is to produce electrons with one mega-electron volt of energy from the chip.

This is approximately equal to the electrical voltage of one million batteries. An additional aim is to create ultra-short (<10^-15 seconds) electron pulses, as required by the design for a scalable accelerator on a chip developed in Darmstadt.

The possible applications for an accelerator such as this would be in industry and medicine. An important long-term goal is to create a compact coherent X-ray beam source for the characterisation of materials. One example of a medical application would be an accelerator-endoscope which could be used to irradiate tumours deep within the body with electrons.

A particular advantage of this new accelerator technology is that the chips could be produced inexpensively in large numbers, which would mean that the accelerator would be within reach of the man on the street and every university could afford its own accelerator laboratory. Additional opportunities would include the use of inexpensive coherent X-ray beam sources in photolithographic processes in the semiconductor industry, which would make a reduction in transistor size in computer processors possible, along with a greater degree of integration density.

Wissenschaftliche Ansprechpartner:

Dr.-Ing. Uwe Niedermayer
TU Darmstadt
TEMF Laboratory
Tel.: (+49) 6151-16 24039
Email: niedermayer@temf.tu-darmstadt.de

Originalpublikation:

Alternating-Phase Focusing for Dielectric-Laser Acceleration
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.214801

Silke Paradowski | idw - Informationsdienst Wissenschaft
Further information:
http://www.tu-darmstadt.de/

More articles from Power and Electrical Engineering:

nachricht New efficiency world record for organic solar modules
12.11.2019 | Forschungszentrum Juelich

nachricht Using mountains for long-term energy storage
12.11.2019 | International Institute for Applied Systems Analysis (IIASA)

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New Pitt research finds carbon nanotubes show a love/hate relationship with water

Carbon nanotubes (CNTs) are valuable for a wide variety of applications. Made of graphene sheets rolled into tubes 10,000 times smaller than a human hair, CNTs have an exceptional strength-to-mass ratio and excellent thermal and electrical properties. These features make them ideal for a range of applications, including supercapacitors, interconnects, adhesives, particle trapping and structural color.

New research reveals even more potential for CNTs: as a coating, they can both repel and hold water in place, a useful property for applications like printing,...

Im Focus: Magnets for the second dimension

If you've ever tried to put several really strong, small cube magnets right next to each other on a magnetic board, you'll know that you just can't do it. What happens is that the magnets always arrange themselves in a column sticking out vertically from the magnetic board. Moreover, it's almost impossible to join several rows of these magnets together to form a flat surface. That's because magnets are dipolar. Equal poles repel each other, with the north pole of one magnet always attaching itself to the south pole of another and vice versa. This explains why they form a column with all the magnets aligned the same way.

Now, scientists at ETH Zurich have managed to create magnetic building blocks in the shape of cubes that - for the first time ever - can be joined together to...

Im Focus: A new quantum data classification protocol brings us nearer to a future 'quantum internet'

The algorithm represents a first step in the automated learning of quantum information networks

Quantum-based communication and computation technologies promise unprecedented applications, such as unconditionally secure communications, ultra-precise...

Im Focus: Distorted Atoms

In two experiments performed at the free-electron laser FLASH in Hamburg a cooperation led by physicists from the Heidelberg Max Planck Institute for Nuclear physics (MPIK) demonstrated strongly-driven nonlinear interaction of ultrashort extreme-ultraviolet (XUV) laser pulses with atoms and ions. The powerful excitation of an electron pair in helium was found to compete with the ultrafast decay, which temporarily may even lead to population inversion. Resonant transitions in doubly charged neon ions were shifted in energy, and observed by XUV-XUV pump-probe transient absorption spectroscopy.

An international team led by physicists from the MPIK reports on new results for efficient two-electron excitations in helium driven by strong and ultrashort...

Im Focus: A Memory Effect at Single-Atom Level

An international research group has observed new quantum properties on an artificial giant atom and has now published its results in the high-ranking journal Nature Physics. The quantum system under investigation apparently has a memory - a new finding that could be used to build a quantum computer.

The research group, consisting of German, Swedish and Indian scientists, has investigated an artificial quantum system and found new properties.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

High entropy alloys for hot turbines and tireless metal-forming presses

05.11.2019 | Event News

Smart lasers open up new applications and are the “tool of choice” in digitalization

30.10.2019 | Event News

International Symposium on Functional Materials for Electrolysis, Fuel Cells and Metal-Air Batteries

02.10.2019 | Event News

 
Latest News

Magnetic tuning at the nanoscale

13.11.2019 | Physics and Astronomy

At future Mars landing spot, scientists spy mineral that could preserve signs of past life

13.11.2019 | Physics and Astronomy

Necessity is the mother of invention: Fraunhofer WKI tests utilization of low-value hardwood for wood fiberboard

13.11.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>