Laser Acceleration
Posted by on Wednesday, October 9, 2013
There has been a lot of news coverage over the last few years of the Large Hadron Collider, and discussions about how it is setting records for the highest energy accelerator, the high costs and the engineering advances. However last week a team of scientists from Max Planck Institute of Quantum Optics in Garching published results of experiments on a more affordable and compact method of accelerating subatomic particles. If successful, future accelerators could be made an order of magnitude smaller and cheaper.
In traditional accelerators, particles travel through tunnels surrounded by large superconducting electromagnets. The magnetic fields cause the charged particles to accelerate, until they reach the energies required. However there are limits to the size of the magnetic fields that can be used before the metal and other materials are damaged by the intense electromagnetic fields.
This new method removes the magnets entirely and relies on laser pulses. Through the use of a specially prepared piece of glass, the laser pulses can be made to travel parallel to the surface for long distances. When charged particles are sent across the same surface, they can get caught in the light waves and effectively 'surf' along. Since the waves are travelling at the speed of light, the particles could in theory be accelerated to any speed (although in practice defects in materials and other technical issues would stop the acceleration before it reached relativistic energies)
The team from MPI are claiming to have accelerated electrons at the same rate as traditional particle accelerators. However there experiment had limited length and has yet to match the final energy and flux of regular accelerators, and much more work is required to develop this latest proof-of-concept experiment into a fully functioning and usable scientific tool.
So perhaps the next generation of particle accelerator will not be the proposed and very expensive Very Large Hadron Collider, but rather a more economical laser based accelerator. It will be interesting to see how this new method develops.
In traditional accelerators, particles travel through tunnels surrounded by large superconducting electromagnets. The magnetic fields cause the charged particles to accelerate, until they reach the energies required. However there are limits to the size of the magnetic fields that can be used before the metal and other materials are damaged by the intense electromagnetic fields.
This new method removes the magnets entirely and relies on laser pulses. Through the use of a specially prepared piece of glass, the laser pulses can be made to travel parallel to the surface for long distances. When charged particles are sent across the same surface, they can get caught in the light waves and effectively 'surf' along. Since the waves are travelling at the speed of light, the particles could in theory be accelerated to any speed (although in practice defects in materials and other technical issues would stop the acceleration before it reached relativistic energies)
The team from MPI are claiming to have accelerated electrons at the same rate as traditional particle accelerators. However there experiment had limited length and has yet to match the final energy and flux of regular accelerators, and much more work is required to develop this latest proof-of-concept experiment into a fully functioning and usable scientific tool.
So perhaps the next generation of particle accelerator will not be the proposed and very expensive Very Large Hadron Collider, but rather a more economical laser based accelerator. It will be interesting to see how this new method develops.
I am a theoretical physicist & mathematician, with training in electronics, programming, robotics, and a number of other related fields.
