The interaction of high-energy and high-power laser pulses with matter produces broadband particle and electromagnetic radiation. In particular, a significant portion of the incoming laser energy is transformed to powerful transient electromagnetic pulses (EMPs) in a broad range of radiofrequencies, microwaves and THz radiation. Such fields depend on laser energy and intensity and can easily exceed the MV/m magnitude – strong enough to represent a significant danger for any electronic device placed inside or outside the experimental vacuum chamber. This has been observed worldwide in experiments with high power lasers.

EMPs pose a very important limitation on the performance of high-power laser facilities for applications as diverse as inertial confinement fusion and laser–plasma acceleration. More severe issues are expected for the upcoming PW-scale lasers. The increase of the repetition rate needed to transition processes such as laser acceleration from scientific proof of principle to “real world” applications, e.g. for hadron therapy, also creates the need for more reliable and efficient EMP protection and mitigation techniques.

Understanding the origin of EMP and the complex temporal and spatial distribution of these electromagnetic fields is of key importance for the development of suitable EMP mitigation schemes for safe facility operation, and also for their potential use for many promising applications, such as laser-driven ion beam acceleration/conditioning. This is constrained by the development of quantitative EMP diagnostic methods and devices that are capable of operating in the harsh conditions of high-power laser experiments.

The members of the present expert group have strong common research interests and extensive expertise on the research activities of laser-generated electromagnetic pulses in the whole RF-μw-THz band, including modeling, diagnostics, mitigation and applications. This will be of direct applicability to all modern laser plasma facilities and importantly to future laser-plasma acceleration and inertial-confinement-fusion plants, and potentially to next generation laser-driven hadron therapy systems. The expert group will promote and focus the activities of each institution to define mutual collaborations and prepare joint experimental campaigns.

For additional information on the Expert Group please contact Fabrizio Consoli (ENEA).

• CELIA, Centre Lasers Intenses et Applications, University of Bordeaux, CNRS, Bordeaux, France
• CESTA, Centre d’Etudes Scientifiques et Techniques d’Aquitaine, CEA, Le Barp, France
• CLF, Central Laser Facility, Rutherford Appleton Laboratory, STFC, Oxfordshire, United Kingdom
• CLPU, Centro de Laseres Pulsados, Salamanca, Spain
• ENEA-ABC, ENEA – Centro Ricerche Frascati, ABC Facility, Frascati, Italy
• GSI, GSI Helmholtzzentrum für Schwerionenforschung Darmstadt, Germany
• HIJ, Helmholtz Institute Jena, Germany
• HILASE, Hilase, Dolni Břežany, Czech Republic
• HZDR, Helmholtz-Zentrum Dresden Rossendorf, Germany
• INFLPR, National Institute for Laser, Plasma and Radiation Physics, Bucharest, Romania
• IPPLM, Institute of Plasma Physics and Laser Microfusion, Warsaw, Poland
• Laserlab DK, Danish Center for Laser Infrastructure, Aarhus Universitet, Denmark
• LENS, Laboratorio Europeo di Spettroscopie Non Lineari, Sesto Fiorentino (Florence), Italy
• LLC, Lund Laser Centre, Lunds Universitet, Sweden
• LULI, Laboratoire pour l’Utilisation des Lasers Intenses, CNRS, Palaiseau, France
• ORION, Orion, Aldermaston, Reading, UK
• PALS, Prague Asterix Laser System, Institute of Plasma Physics, Prague, Czech Republic
• STRATH, University of Strathclyde, Glasgow, United Kingdom