LULI (Palaiseau, France)
Laboratoire pour l’Utilisation des Lasers Intenses, CNRS
LULI operates two multi-beam laser facilities: APOLLON, a Ti:Sapphire shot-per-minute facility offering an exceptional multi-PW peak power, and LULI2000, a highly energetic Nd-glass laser. APOLLON allows exploring high-field physics and generating extreme particle and radiation beams for applications. LULI2000 couples high-energy and high-power laser pulses onto a target together with external high-amplitude pulsed magnetic fields for high-energy-density physics investigation.
Research highlights
Fusion sciences
An unique platform allowing fusion-relevant plasma magnetization has been developed on LULI2000; it was used to study – in conditions relevant to indirectly- and directly-driven magnetized ICF – laser-plasma instabilities [Phys. Rev. Lett. 130, 265101 (2023)].
Laboratory astrophysics & planetology
LULI2000 allows reproducing the interaction between a molecular cloud and an external agent (e.g., a supernova remnant) and understanding how star formation can thus be triggered [Matter Radiat. Extrem. 7, 036903 (2022)]. It allows also determining the melting curve of key molecular systems (such as superionic ammonia) at planetary interior conditions [Nature Phys. 19, 1372 (2023)].
Secondary radiation & particle sources
The APOLLON parameters have particular advantages to generate brilliant sources of particles, e.g. of neutrons using a simple thin foil as a proton accelerator, followed by a high-Z neutron converter exploiting the spallation process [Matter Radiat. Extrem. 6, 64402 (2021) & 7, 24401 (2022)].
Expertise
Access to the APOLLON laser facility allows studying laser-matter interaction in the yet unexplored ultra-relativistic regime and developing applications, especially those of the energetic and ultra-short secondary sources produced at intensities up to 2 1022 W/cm2. Topics currently under investigation are electron acceleration, ion acceleration (exploring advanced schemes to break the 100 MeV limit or to produce neutron and positron sources, tackling warm dense matter physics and laboratory relativistic astrophysics), x-ray production (harmonics from solid targets, FEL-type or betatron sources) and high-field physics (to study QED effects in laser-plasma interaction). Experimental research is supported by numerical simulations using the SMILEI open-source PIC code.
The experiments conducted on LULI2000 are based on laser irradiation of solid or gaseous targets to produce high-energy density matter at extreme temperature and pressure conditions, often in out-of-equilibrium regimes. The versatility of the facility and the scientific expertise of the LULI host researchers allows covering many fields of research, from fundamental – magnetized or not – plasma physics to shock-loaded material investigation, inertial fusion sciences, laboratory astrophysics and planetology. Laser-based secondary sources of high-energy particles and radiation are commonly used for innovative diagnostic techniques or for warm dense matter production.
Equipment offered to external users
The facilities offer access to gas & solid target characterization laboratories, target alignment benches and a large palette of state-of-the-art instrumentation. Laser diagnostics are implemented on the whole set of laser beams.
APOLLON allows combining on target two fs pulses at ultra-high power (F1 and F2) and a low-energy fs probe beam (F4) (see key parameters on the table below). The fundamental wavelength is 0.8 µm. Alignment on target is done within one focal spot and 70% of the energy is enclosed in the diffraction spots. The laser repetition rate is one shot per minute over 5 hours per day and for a fixed campaign duration of 4 weeks (including 2 weeks for set-up). In the SFA experimental area, the F1 and F2 beams are focused by off-axis parabolas with short focal lengths – 1m (F1) and 42cm (F2) – to allow, thanks also to implementation of deformable mirrors, reaching the ultimate intensities; the interaction geometry with the target chamber is quite fully modular. In the LFA experimental area, F1 are F2 will be focused from 2026 inside separate target chambers thanks to long focal length optics (3m or 9m for F2, 8m or 20m for F1); F4 is not delivered to LFA.
| APOLLON | F1 | F2 | F3 | F4 |
| Max. energy | 60 J mid-2022 150 J ultimately |
20 J | up to 250 J, depending on the energy required by F1+F2 | 300 mJ |
| Duration | 20 fs 15 fs ultimately |
20 fs 15 fs ultimately |
1 ns | < 20 fs |
| Contrast | 10–12 | 10–12 |
On LULI2000, the S2002 experimental area is devoted to experiments requiring two kJ/ns laser chains (NORTH and SOUTH) and one probe beam (the BLUE beam, operated in the ns regime), while the radio-protected S2001 experimental area is operated with the NORTH chain, an high-energy CPA laser chain (PICO2000) and the BLUE probe beam (see key parameters on the table below). The fundamental laser wavelength is 1.06µm. Incidence angles on target are pre-determined. Upon request, the nanosecond pulses can be shaped with differentiated temporal profiles; the maximum energy delivered in the ns regime will thus depends on the pulse duration. All the chains are synchronized with ps jitters; they can be frequency-doubled and equipped with wavefront correction systems to deliver full-energy pulses every 90’ (4 to 6 shots per day). The BLUE probe beam can even be frequency-tripled. Focusing of the ns beams is ensured through HPP phase plates (of diameter 500µm and 800µm, plus 300µm in S2001 and 1300µm in S2002) while off-axis parabolas are used for the CPA beams (with, at best focus, a focal spot diameter of ~15µm).
An electromagnetic pulser, allowing production of external pulsed magnetic fields of ~30T, can be implemented close to the target chambers. Sophisticated laser-based diagnostics (FDI, VISAR, Thomson scattering, x-ray & proton radiography) can be activated.
| LULI2000 | Duration | Max. energy on target (at the fundamental wavelength) |
Beam diameter |
| NORTH | 0.5-15 ns | 800 J | 175 mm |
| SOUTH | 0.5-15 ns | 800 J | 175 mm |
| BLUE | 0.5-15 ns | 50 J | 70 mm |
| PICO2000 | 1-30 ps | 60 J | 175 mm |