Speaker
Description
Chirped pulse amplification (CPA) laser systems, exemplified by the Advanced Titanium-Sapphire Laser (ATLAS) operated in the Centre for Advanced Laser Applications (CALA) at the Ludwig-Maximilians-University (LMU) Munich, are capable of generating laser pulses with Petawatt peak power and ~30 fs duration. When focused tightly onto targets, typically (sub-)micrometer thin foils, these pulses ionize and subsequently induce relativistic electron motion which separates electrons from ions. The emerging rectified fields of order ~MV/µm results in rapid acceleration of dense ion bunches.
This presentation will explain the physical processes involved and elucidate the characteristics of ion sources, in particular the accessible energy distributions using current technology [1]. The ultrashort pulse enables acceleration within less than one picosecond, ensuring a similar precise synchronization of the bunch with the laser – a pivotal aspect for new application possibilities. Notably, this synchronization allows for time-resolved investigations of post-proton energy deposition processes within targets such as water [2]. The intense plasma fields also facilitate ionization of heavy ions into high charge states. Recent observations include the acceleration of Neon-like gold to MeV/u kinetic energies, along with initial indications of fission within the microscopic plasma [3].
At CALA, our active focus lies in pushing the boundaries of technology to leverage the potential applications of laser-plasma acceleration. Our efforts encompass the development of instrumentation capable of characterizing the spatial and energy distributions of individual, intense ion bunches using ultrasound pulses [4]. We are now working on providing fresh laser-ion converters, known as targets, with the repetition rate of 1 Hz dictated by the PW-laser. These advancements mark a significant step towards practical implementation, aiming to spark curiosity and stimulate engaging discussions.
[1] Schreiber, J., Bolton, P. R. & Parodi, K. Invited Review Article: "Hands-on" laser-driven ion acceleration: A primer for laser-driven source development and potential applications. Rev Sci Instrum 87, 071101, doi:10.1063/1.4959198 (2016).
[2] Prasselsperger, A. et al. Real-Time Electron Solvation Induced by Bursts of Laser-Accelerated Protons in Liquid Water. Phys Rev Lett 127, 186001, doi:10.1103/PhysRevLett.127.186001 (2021).
[3] Lindner, F. H. et al. Charge-state resolved laser acceleration of gold ions to beyond 7 MeV/u. Sci Rep 12, 4784, doi:10.1038/s41598-022-08556-8 (2022).
[4] Gerlach, S. et al. Three-dimensional acoustic monitoring of laser-accelerated protons in the focus of a pulsed-power solenoid lens. High Power Laser Science and Engineering 11, doi:10.1017/hpl.2023.16 (2023).
