The objective of this application to access the infrastructure APOLLON, long focal area (LFA), is to perform the first experiment at PW-level of a laser-plasma electron accelerator with a hybrid solid-gas approach that we have recently demonstrated at TW-level at the Laboratory of Applied Optics (LOA) that aims at enhancing the electron charge per laser shot.
The hybrid approach associates the strengths of high density plasma mirrors (PMs) to the ones of laser wakefield accelerators (LWFAs): by positioning a gas jet at the front of a solid target, the ultrahigh intensity (UHI) laser can reflect onto the PM and eject a very high charge from this solid-like density plasma into the LWFA resulting from the propagation of the reflected laser into the gas. This high charge injection into the LWFA occurs with a very localized manner – at the very surface of the PM – which enables to accelerate all the injected electron bunch over the same distance and to obtain high charge electron bunches with a low-energy spread below 10%.
In 2022, we have performed at LOA the first proof-of-concept at 13TW-level measuring 18pC / 200MeV electron bunches with 7% energy spread. From our PIC simulations, we can expect at the APOLLON beamline electron bunches of more than 500pC with energies peaked between 0.5 and 1GeV with an energy spread below 5%. The objective of the proposed experiment is to generate and characterize such electron bunches.
This application takes place in a larger project which has received an ANR 2022 funding in collaboration with LOA and CEA Saclay that aims at producing high charge / high quality electron beams to demonstrate their use for biomedical applications such as FLASH radiography.