LLNL's National Ignition Facility Achieves Fusion Ignition Milestone with G&H Crystals

Posted  by GoPhotonics


A team of researchers at the Lawrence Livermore National Laboratory (LLNL) achieved a historic milestone through its National Ignition Facility (NIF), igniting fusion using inertial confinement fusion (ICF) above breakeven for the very first time. This groundbreaking accomplishment was powered by a formidable laser employing G&H’s self-grown KDP and KD*P crystals, integral components within the laser’s Plasma Electrode Pockels Cell (PEPC) and final optics assembly. G&H representatives, in a recent visit to NIF, bore witness to the cutting-edge advancements in optics and photonics pivotal to this breakthrough in fusion energy.

Known as one of the 7 Wonders of NIF, KD*P or KD2PO4 crystals (potassium phosphate crystals with deuterium substituted for hydrogen) have undergone continual enhancements at G&H in Highland Heights, Ohio. These crystals, cultivated in heavy water salt solutions, boast a growth period of up to 2 years and can weigh as much as 400 kg upon completion. Following growth, they are meticulously fashioned into finished optics exceeding dimensions of 40 x 40 cm at the Gooch & Housego facility.

“G&H crystals play an important role in the success of NIF’s experimentation process. Our KD*P crystals are responsible for converting the infrared laser energy into ultraviolet, that ultimately is focused onto the target to create the necessary X-rays responsible for starting the fusion process. Our unique crystal growth capability facilitates LLNL’s pursuit of fusion ignition – which has been a scientific grand challenge,” says Dr. Matthew Whittaker, Crystal Growth and ICF Manager at G&H. “We are committed to continue supporting the next steps and expansion of this technology toward a clean energy future.”

These specific crystals are a critical part for NIF’s frequency tripled, high-energy Neodymium (Nd)-glass lasers. They are used as frequency converters to generate the UV light and as electro-optic switches within the PEPC. Gooch & Housego has collaborated with LLNL and NIF for decades, in particular through the development of large aperture crystalline optics. The underlying root for this prolific partnership lies in our company’s consistency in producing reliable crystals which enable NIF to operate at higher laser fluence, time and time again.

“Pushing the performance envelope in optics and photonics has always been a driving force behind our R&D efforts, with crystal growth for ICF being core to our technology roadmap” says Stratos Kehayas, President of Photonics at G&H. “As LLNL scientists focus on constantly improving yield on NIF and supporting other missions, we will be here to support them with our newest innovations in terms of crystal optics. Our KPD and KD*P crystals made in our Cleveland US facility, among other components, are paving a steady way for history to be made in the fusion sector. As such, our teams are ready to transform the 60+ year-old dream of nuclear fusion into reality with the power of photonics.”

Click here to read the article titled, "Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment."