Plasma Accelerator

29 Apr 2021

Tony Haynes would have liked this one. At ... an intense laser pulse in an ionised gas drives a bubble shaped plasma wave consisting of electrons. A bunch of electrons ride the wave like a surfer as it accelerates to high energies over a short distance. Plasma is coming of age as a source of cheap energy, it would seem. Scientists from the University of Hamburg used an accelerator to test a technique that allows energy distribution to be kept to a narrow band, and therefore potentially controllable. The results of the experiment appear in two paper in Physical Review Letters - see for example ...

At ... explaining electric fields in sand storms. One lesser known aspect of sand storms is that they can generate high magnitude electrical fields. Experiments have shown they pick up static electricity through collisions between sand and the ground - but once airborne, the electrified sand seems to show sand grains spontaneously separate. They think they know how. Do they?

At ... campfires may offer a clue to the solar heating mystery. The outer atmosphere of the sun is very hot. How does that occur. The 'Solar Orbiter Extreme Ultraviolet Imager' is proving a useful tool - even in the short period after its launch. It has revealed hundreds of small flickering lightenings on the surface of the sun  which have been christened campfires. They last between 10 and 200 seconds.