Lawrence Livermore National Laboratory

Research Collaborations with Germany Planned

Lab Co-hosts Target Fabrication Specialists Meeting

An international group of scientists, engineers, and technicians gathered at the National Security Technologies site in Nevada last week to focus on communicating progress in developing and producing targets in the areas of inertial confinement fusion (ICF) and high energy density (HED) science. The 22nd Target Fabrication Specialists Meeting was the largest in recent history, with nearly 130 participants from four different countries.

A NIF Beryllium Target CapsuleA NIF beryllium target capsule.

The event, held March 12-16, was sponsored by the Department of Energy (DOE), the National Nuclear Security Administration (NNSA), the NIF & Photon Science Directorate, and the Laboratory.

Opening remarks came from Mike Campbell of the Laboratory for Laser Energetics (LLE) at the University of Rochester, followed by a DOE update by Tiberius Moran-Lopez of NNSA.

The scientific meeting covered the major aspects involved in fabricating targets for experiments on high-power, high-energy laser and pulsed-power facilities, ranging from cryogenics to robotics to metrology. There also were talks by a number of plasma physicists, the end users of targets, from LLNL, LLE and Los Alamos National Laboratory on progress in target experiments and designs.

Participating in discussions were leading researchers from the United States, Japan, France, and the UK. In addition to LLNL and NIF&PS representatives, the event attracted scientific partners in the ICF and HED communities, including Los Alamos and Sandia national laboratories, Schafer Corp., the University of Rochester, General Atomics, CEA (the French Alternative Energies and Atomic Energy Commission), Hamamatsu Photonics KK of Japan, and the Atomic Weapons Establishment Target Fabrication Group of the UK.

There were 133 presentations at the conference, with the Lab contributing 39 presentations and co-authoring more than half. Peer-reviewed papers will be published in Fusion Science and Technology, a journal of the American Nuclear Society.

The Larry Foreman Award, presented for excellence in target fabrication, was awarded to retired LLNL employee Robert Cook for his body of work in capsule and coating developments for ICF targets as well as for mentoring future generations of scientists in this area.

Research Collaborations with Germany Planned

Stepped-up collaborations between LLNL and the German laser and optics industry were the subject of a recent visit to the Laboratory by Wolfgang Tiefensee, economics and science minister of the German state of Thuringia, and a delegation of German officials, scientists, and business leaders.

The visit included a briefing on the Lab’s program in advanced high-power laser systems by Constantin Haefner, program director for Advanced Photon Technologies; a discussion between Haefner and Andreas T√ľnnermann, director of the Fraunhofer Institute for Applied Optics and Precision Engineering (IOF) in Jena, Germany; and a tour of NIF.

NIF&PS Officials Meet with the German DelegationNIF & Photon Science officials meet with members of the Thuringian delegation to discuss topics of mutual interest. Credit: Jason Laurea

Haefner said the potential for collaboration between the Laboratory and Fraunhofer was based on the two institutions’ mutual desire to develop high-peak-power and high-average-power laser and laser-based particle accelerator technology for “societietally impactful” applications such as medicine, biology, materials science, and industrial applications.

Fraunhofer, along with Friedrich Schiller University (FSU) in Jena, developed a fiber-based, kilowatt-class ultrafast laser system that uses miltidimensional coherent pulse addition and delivers pulses with 12 megajoules of energy and 260-femtosecond (quadrillionth of a second) pulse duration, representing the highest energy achieved by an ultrafast fiber-based laser system to date.

LLNL, a long-time leader in laser and photonics technology, recently completed development of the world’s highest-average-power diode-pumped petawatt laser system, the High Repetition Rate Advanced Petawatt Laser System (HAPLS). HAPLS was designed, developed, assembled and tested at LLNL for delivery this summer to the European Union’s Extreme Light Infrastructure Beamlines (ELI-Beamlines) facility in the Czech Republic.

“Both LLNL and Fraunhofer are interested in pushing the development of high-average-power short-pulse laser power technology relevant for real-world applications,” Haefner said. “While we pursue different approaches, we share a lot of the technical challenges ahead of us—key technologies such as aperture tiling, high-average-power pulse compression, advanced control systems, and longevity optics are required for both approaches. Faster progress and new ideas are expected if the two world record holders leverage their unique expertise.”

In order to secure international exchange between the two institutions, avenues for collaboration and guest residencies at LLNL, Fraunhofer IOF, and the Institute for Applied Physics at FSU were discussed.