Gone In 60 Nanoseconds – Hot Rod Particle Accelerators

Everything we know about reality, we learned from particle accelerators. But as reported on PhysicsWeb, current accelerators cannot keep pushing tiny pieces of matter to higher and higher levels of energies and so uncover deeper and deeper scientific secrets. Most accelerators use radio-frequency waves confined in metallic cavities to give particles a “kick” in energy each time they pass through the cavity. However, the acceleration gradients that these machines can achieve are limited, and the only way to reach higher energies is to build bigger accelerators with more cavities. Governments are beginning to balk at the taxpayer expense of such efforts, as the cancellation of the Superconducting Super Collider (SSC) on budgetary grounds shows. A new and possibly much cheaper alternative called a “laser wake field” accelerator would rely on exploiting the radiation pressure of an intense laser pulse to displace the electrons in a plasma, leaving a large electric field in its wake. Recent experimental results by Viktor Malka of the Ecole Polytechnique in France show that an electron at rest can be accelerated from zero to an energy of 200 MeV in a distance of just 1 mm. Any physics geek can just sit there in slack-jawed amazement at such a number; the rest of you will have to take our word for it: Wow. This is a terrestrial particle-acceleration record; at rates like this, the current high-energy particle frontier could be reached in an accelerator only one metre long compared to the current Fermilab’s mile-diameter underground accelerator ring. As exciting as these results are, they are really just the tip of the iceberg of what laser-wake-field accelerators could do. There is still a long way to go to realize all the requirements necessary for a working accelerator based on this new method, but Malka and others have made and continue to make significant steps towards making it a…reality.