Molecular machines and other adventures in nanomechanics
Solar flares are powered by an impulsive release of magnetic energy stored
in the solar atmosphere. The release of magnetic energy is heating coronal plasma, but as much as half of the released energy goes into particle acceleration. The acceleration mechanisms that provide these efficient conversions of magnetic energy into supra-thermal particles are currently not well understood.
In the past years however, significant progress has been made on the
observational side; thanks in particular to hard X-ray observations by Reuven Ramaty High Energy Spectroscopic Imager (RHESSI), a NASA small explorer mission. After an extensive introduction, I will review recent observational results obtained by RHESSI. Furthermore, I will briefly describe future
instrumentation such as the hard X-ray instrument STIX on board ESA’s Solar
Orbiter mission and a sounding rocket experiment called FOXSI that successfully
used hard X-ray focusing optics for solar observations.