Laser-plasma acceleration of ions – the opportunities and riddles of water
The Nobel-prize winning Chirped Pulse Amplification technique has enabled the generation of femtosecond laser pulses with peak powers exceeding one Peta-Watt. When tightly focused, the intensity exceeds the plasma formation threshold in any material by orders of magnitude. This results in free electrons oscillating at velocities close to the speed of light, with the radiation pressure becoming much larger than the transverse electric force. Such relativistic laser-plasmas enable novel approaches to accelerating electrons and ions, offering exciting possibilities for compact particle accelerators with applications in fields such as physics, material sciences, and medicine.
However, this technique represents more than just a technological advancement – it opens up new experimental opportunities that were previously inaccessible or difficult to achieve with conventional (non-laser driven) machines, some of which have just been forgotten. At the LMU Munich, our group is working to develop laser-driven ion (LION) acceleration using the Petawatt Advanced Ti:Sa LASer (ATLAS) at the Centre for Advanced Laser Applications (CALA). Our ultimate goal is to contribute to medical physics research, particularly in the field of ion-beam tumor therapy. This journey is a long one that requires significant advances in laser technology, plasma targets, and instrumentation such as detectors and beamlines. In this talk, I will explain the core principles of laser-plasma acceleration, highlight the associated challenges and possibilities for applications, and uncover the mystery surrounding the role of water in our research.