Electron accelerator
Can you influence the orbit of electrons with a magnet? The stand has been created in collaboration with the Department of Physics and Astronomy.
What do we see on the stand?
When charged particles (here electrons) collide with atoms, the atoms can emit light to get rid of the energy from the collision - this is how we can see the trace of the electrons in the glass ball. Similarly, charged particles from the Sun create the aurora in the Earth's magnetic field. The electrons from a filament travel first straight in one direction and then in a circle. You can influence the trajectory by changing the strength of the magnetic field created by moving charges, in this case the current passing through the coils on the sides of the glass ball.
What is Uppsala University doing in this area?
The Department of Physics and Astronomy studies methods for building accelerators that can produce beams of photons and other particles. What we show here is a small particle accelerator for electrons where we can influence the trajectory with a magnetic field. Charged particles from the Sun colliding with molecules and atoms in our atmosphere give rise to the Northern Lights. The light emitted from this process also tells us which molecule emitted it, which can provide clues to the structure of the atmospheres of distant planets and stars. Light and accelerated particles are also used in experimental materials research to study the composition and electronic structure of different material systems.
How is this used in society?
The interaction between particles and light is fundamental to much of modern physics. The light from distant stars and galaxies helps us understand the history of the universe and also the interactions between the smallest components of matter. Light (and ionising electromagnetic radiation, such as X-rays) can be used to study the constituents of different materials (and processes within them), which can be used to create better and more efficient technologies. The physics that describes the interaction between electrons and photons (light particles) is the most accurate model of reality that has been tested experimentally.