Descrizione del progetto
Sondare l’elettrodinamica quantistica in campi laser ad alta intensità
L’elettrodinamica quantistica (QED, quantum electrodynamics) combina elettromagnetismo e meccanica quantistica per spiegare le modalità con cui la luce interagisce con la materia. Sebbene sia molto accurata, la teoria non si rivela del tutto precisa per quanto riguarda i campi di luce ad alta intensità. Finanziato dal Consiglio europeo della ricerca, il progetto EXAFIELD si prefigge di spingere il suo regime perturbativo in laboratorio utilizzando un laser ad alta intensità riflesso da uno specchio di plasma a velocità relativistiche. I ricercatori faranno quindi collidere questo «fascio Doppler potenziato» con fasci di elettroni ultracorti prodotti da generatori laser di plasma, consentendo l’esplorazione di aree della QED finora sconosciute. I risultati del progetto potrebbero permettere ai ricercatori di determinare i limiti dei modelli attuali e aprire nuove aree di ricerca nel regime non perturbativo della QED.
Obiettivo
Quantum Electrodynamics (QED) is the theory that unifies electromagnetism and quantum mechanics to describe how light and matter interact. Considered as one of the most accurately tested theories, it led Richard Feynman to call it “the jewel of physics”. Yet, in the strong-field (SF) regime, when the light fields are ultra-intense, this theory is only treated perturbatively and the non-perturbative regime of SF-QED remains a terra incognita as even no theory exists to predict the behaviour of nature.
The advent of multi-PW laser infrastructures now makes the SF-QED regime within experimental reach when considering the collision of relativistic electrons with such light pulses focused above 10^22W/cm2. Yet, all planned experiments to probe SF-QED with current technologies only propose to investigate its perturbative regime, expected to be well described by theory.
In the EXAFIELD project, I propose a new concept of experiments to exceed the perturbative limit of SF-QED in the lab. This will be achieved by reflecting an ultra-intense laser pulse off a plasma mirror at relativistic speed. The strong Doppler effect occurring upon reflection up-converts the near-infrared laser pulse down to the extreme ultraviolet range which enables both temporal compression to the attosecond timescale and spatial compression down to sub-micron size. This results in a considerable intensity boost at focus of more than three orders of magnitude up to a few-10^25W/cm2.
The collision of such a “Doppler-boosted beam” with ultrashort electron bunches generated from laser-plasma accelerators will allow us to access regimes where the SF-QED can no longer be treated perturbatively, producing very strong signatures in the lab. Characterizing how the observations deviate from the perturbative theory will enable us to determine the limits of validity of the perturbative models and will open to a new area of research toward the understanding of the non-perturbative regime of SF-QED.
Campo scientifico
Parole chiave
Programma(i)
- HORIZON.1.1 - European Research Council (ERC) Main Programme
Argomento(i)
Meccanismo di finanziamento
HORIZON-ERC - HORIZON ERC GrantsIstituzione ospitante
75794 Paris
Francia