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Jupiter Laser Facility

Titan, Janus, and COMET Laser Platforms

  • Lawrence Livermore National Laboratory

Located in the Tri-Valley area to the east of the San Francisco, Livermore, California is one of California’s oldest wine regions and home to the world-renowned Lawrence Livermore National Laboratory, dedicated to ensuring the safety, security, and reliability of the nation’s nuclear deterrent for more than 60 years.

Capabilities

Robert Cauble

Robert Cauble

Phone: +19254224724

Email: cauble@llnl.gov

Read Bio

Overview

JLF is an intermediate-scale, open laser facility dedicated to high-energy density science, with three operating laser systems and target areas: Titan, Janus, and COMET. JLF is the 5th highest energy laser in the US. In scale and operation, JLF is similar to lasers at the Central Laser Facility at Rutherford- Appleton Laboratory in the UK and the Laboratoire pour l’Utilisation des Lasers Intenses (LULI) located at École Polytechnique in France. Access to JLF is obtained through an annual call for proposals, and a fraction of the user time at JLF will be accessible through LaserNetUS. More than 100 Ph.D.’s have been granted that included thesis work at JLF, and the facility has been acknowledged in over 200 peer-reviewed publications. The JLF facility at LLNL provides 50% of beamtime to LaserNetUS and the other 50% is administered by LLNL through JLF annual call. These beamtime allocations are separate and duplicate proposals are discouraged. The goal of LaserNetUS is to provide complementary opportunities and not meant to replace or duplicate the annual JLF call.

Janus and Titan

After more than 10 years of operation, Janus and Titan are presently undergoing extensive refurbishment, with an expected return-to-full-operations date of March 2022. Janus and Titan refer to the target areas and to the operational mode: long-pulse (Janus) or short-pulse (Titan). They will make use of three high-energy beamlines, one of which is shared between the two target areas. All three beams employ glass amplifiers and have a 30-minute duty cycle. All experiments are hands-on for users.

Titan will have a dedicated ps beam, 0.4 to 20 ps, with energies up to 300 J at fundamental (1053 nm) into a 2-m-diam chamber; the option of full-aperture conversion to 2ω (up to 100 J) will follow later in the year. (Beam energy is limited to 120 J until new pulse-compression gratings have been qualified.) The Titan short-pulse beam uses an f/3 final optic, but f/10 can be arranged. The focal spot is < 10 μm with a strehl > 0.6. The prepulse level is better than 10-7 (10-14 using 2ω). Using a beam-splitter inside the chamber, the beam can be split into two differently pointed beams. A second, long-pulse, beam – 0.35-20 ns with energy up to 1 kJ (1ω) or 700 J (2ω) – can be simultaneously transported to the chamber with arbitrary timing between the beams. A mJ-level probe beam is also available.

Janus will have a dedicated long pulse beam with a second long-pulse beam available. Both beams are 0.35-20 ns with energy up to 1 kJ (1ω) or 700 J (2ω) and will have largely arbitrary pulse-shaping. Both beams have polarization control and can be detuned by ~ 1 nm in wavelength. The minimum spot size is < 20 μm with a strehl > 0.6. Phase plates are available for 200, 400, 600, 100, and 2000-μm spot sizes. A dual-echelon VISAR system and streaked optical pyrometry are standard diagnostics in Janus. A mJ-class Ti:Sapph probe is also available.


COMET

COMET is a 5-minute-rep-rate laser with either short-pulse (0.5-750 ps) or long-pulse (0.5-5 ns)  configuration and energy up to 12 J. COMET has its own cylindrical chamber. Following some brief training, users are permitted to charge and fire COMET.

More information can be found at jlf.llnl.gov.

COMET Short pulse

Parameter Value Unit Additional Information
Center Wavelength 1053 nm  
Pulse duration (I FWHM) 0.5 ps  
Max energy on target 10 J  
Shot energy stability   % unmeasured
Focal spot at target      
F/number f/3,6    
intensity FWHM 6 μm  
Repetition Rate 15 hr-1  

Janus 1ω

Parameter Value Unit Additional Information
Center Wavelength 1053 nm  
Pulse duration (I FWHM) 0.5 ns to 15  Shaped pulse
Max energy on target 700 J 700
Shot energy stability 10 % r.m.s.      
Focal spot at target     In Titan target chamber
intensity FWHM 200 µm phase plate
  600 µm phase plate
  1000 µm phase plate
Repetition Rate 3.3 Hz   burst mode

Janus 2ω

Parameter Value Unit Additional Information
             
Center Wavelength 527 nm  
Pulse duration (I FWHM) 0.5 fs to 15 ns, shaped
Max energy on target 100 J  
Shot energy stability 10 % r.m.s.      
Focal spot at target     In Titan target chamber
intensity FWHM 200 µm phase plate
  600 µm phase plate
  1000 µm phase plate
Repetition Rate 2 hr-1   burst mode

Titan

Parameter Value Unit Additional Information
             
Center Wavelength 1053 nm  
Pulse duration (I FWHM) 0.7 ps 40
Max energy on target 130 J  
Shot energy stability 10 % r.m.s.      
Focal spot at target      
F/number f/3   Split beam capability available for F/3
intensity FWHM 10 µm Measured at low laser power
Strehl ratio 0.5    
Energy containment   % within   µm radius
F/number f/10          
focal spot FWHM 29 µm Measured at low laser power
Strehl ratio 0.5          
Energy containment 86 % within 28 µm radius
Pointing Stability   µrad (Typically within beam spot diameter)
Pre-pulse contrast      
ns scale     @ ns in progress
ps scale 10-5   @ 200 ps
Repetition Rate 2 hr-1 or 1/hr if Janus uses west beam

Contacts

Have a question or need assistance with your research?

Please address
inquiries to:

Email: cauble@llnl.gov