The L4 Aton system architecture
The L4 laser system can operate in two main modes:
- All the energy can be used to generate a power of 10 PW in a single beam. By-pass of the compressor is possible in order to use the chirped nanosecond (ns) beam directly.
- The main amplifier can deliver almost 2 kJ in a narrowband ns beam with variable temporal shaping seeded by a separate front end. At the same time, the broadband front end can seed the first main amplifier and thus provide a 200 J-class PW pulse.
The L4 laser chain is composed of a broadband ultrafast oscillator, picosecond OPCPA preamplifier, nanosecond OPCPA stages, and two main amplifier stages based on Nd:glass-gain media pumped by flashlamps. The resulting nanosecond pulses are compressed in a dielectric grating compressor.
L4 beam line design parameters (main beam)
| Output pulse energy (main beam compressed) | >1,800 J in single aperture |
| Pulse duration (CPA regime) | <150 fs FWHM (adjustable to 100 ps) |
| Pulse duration (non-CPA regime) | 0.5–5 ns (temporal shaping adjustable in 150 ps steps) |
| Repetition rate | 1 shot per minute |
| Peak power | 10 PW |
| Pump laser technology | flashlamp-pumped Nd:glass amplifiers |
| Output laser pulse energy RMS stability | better than 10% rms |
| Output laser beam RMS pointing stability | <10 µrad |
| Laser control system | Labview and EPICS |
| Output pulse external synchronization relative to the facility clock | <20 ps to RF clock with any delay relative to facility clock |
| Beam format | rectangular superGaussian |
| Beam size of compressed beam | <550×550 mm |
L4 current parameters
Short Pulse beamline (CPA regime)
| Output pulse energy | >1,500 J |
| Pulse duration (CPA regime) | ~150 fs FWHM |
| Central wavelength | 1060 nm |
| Maximum Repetition rate | 1 shot per minute |
| Front-End Energy / repetition rate | 4.8 J / 5 Hz |
| Pump laser technology | flashlamp-pumped Nd:glass amplifiers |
| Output laser pulse energy RMS stability | better than 2.5% RMS |
| Output laser beam RMS pointing stability | <8 µrad |
| Laser control system | Labview and EPICS |
| Output pulse external synchronization relative to the facility clock | <20 ps to RF clock with any delay relative to facility clock |
| Beam format | square super-Gaussian |
| Clear Aperture of compressed beam | 650×650 mm |
L4 current parameters
Long Pulse beamline (Non-CPA regime)
| Design Output pulse energy | >1,900 J |
| Pulse duration (Non-CPA regime) | 150 ps to 10ns (pulse shaping with 150ps step and high double pulse contrast) |
| Central wavelength | 1053 nm |
| Maximum Repetition rate | 1 shot per minute |
| Front-End Energy / repetition rate | 30 J / 1 shot per minute |
| Pump laser technology | flashlamp-pumped Nd:glass amplifiers |
| Output laser pulse energy RMS stability | better than 2.5% RMS |
| Output laser beam RMS pointing stability | <8 µrad |
| Laser control system | Labview and EPICS |
| Output pulse external synchronization relative to the facility clock | <20 ps to RF clock with any delay relative to facility clock |
| Beam format | square super-Gaussian |
| Clear Aperture of output beam | 323×323 mm |
| Auxiliary CPA Beam Energy / Pulse Duration | 100 J / 150 fs |
Delivery of the system
The delivery of the L4 Aton laser system was contracted with the United States-Lithuanian consortium of National Energetics and EKSPLA in September 2014.
The main subcontractors are Schott and Lawrence Livermore National Laboratory.
ELI Beamlines staff is in charge of delivering for the following subsystems:
- Full diagnostics of the compressed 10 PW beam
- Design of the vacuum vessel for the 10 PW compressor
- Design and delivery of optomechanics for the 10 PW compressor
- Laser timing platform
- Contribution to the development of long pulse OPCPA amplifiers.
L4 ATON Compressor
Length: 18 m
Height 4,5 m
Width 3,6m
Weight 55 tons
L4 ATON video
Manufactured by Streicher, Czech republic
References: Bedrich Rus, bedrich.rus@eli-beams.eu
