A plan to give LIFE to laser and photon sciences

(Editor’s note: This is the next in a series of interviews with key leaders of the 100-day science and technology road mapping project. The project centers on seven focus areas: stockpile stewardship science; nuclear counterterrorism and forensics; cyber and space security and intelligence; biosecurity; regional climate modeling and impacts; LIFE — Laser Inertial Fusion-Fission Energy (LIFE); and advanced laser optical systems and applications. Today, hear from Chris Barty, who is spearheading the advanced laser optical systems and applications area of the plan.)

Chris Barty began his career at the Lab in 2000. He has been chief scientist for the Laser Science and Technology Program and played a pivotal role in the establishment of the Photon Science and Applications Program that he now directs. It's part of the National Ignition Facility and Photon Sciences Prinicipal Directorate.

His technical interests include development of new optical capabilities for fusion-energy drivers, fast ignition, directed energy systems, high-energy-density science, nuclear photo-science and laser-based X-ray applications of relevance to national security-related missions.

He received his Ph.D. in applied physics from Stanford University.

The Photon Science and Applications Program of the NIF and Photon Science Directorate is the R&D arm for the directorate and in a lot of ways, it’s our job to think about what the next thing is. So this was a very natural thing for us to want to be involved in.

It was always my perspective from the outside that Livermore was ‘lasers, lasers nothing but lasers’, that’s what LLNL stood for. Since coming here, it’s become even more evident.

We did a recent analysis for one of our DoD customers where we looked back at the history of lasers at the Lab and came to the realization that the Lab has had for about 35 years now, a thousand people a year working on advanced lasers and optics R&D. When you think about that, that’s 35,000 people years of accumulated R&D base that the Lab has, and frankly I don’t think any other place in the world has that.  It really is a unique asset for Livermore.

My general area of interest for this effort would be photons; that is the overarching effort. We’ve listed this area as laser optical systems and applications.

Each one of those words is important to us; we think about advanced laser sources, we think about them as systems, and we think about the advanced applications of those systems.  That’s our vision of what we want to go forward with respect to where the Lab can play a critical role.

We have two big audacious goals that we are looking at. One has to do with using lasers to create an entirely new class of gamma ray light sources — light sources we call a mono-energetic gamma ray source or mega ray source.  Mega ray sources produce photons in the gamma ray regime whose brilliance — how bright they are and the number of photons coming out in a particular angle and color — exceeds that of the best machine in the DOE complex right now by 15 orders of magnitude, if we do this right.

That leap and capability is one that often leaves the user asking ‘What am I going to do?  I’ve never thought of what I would do with 15 orders of magnitude.’

That is basically our big goal for that area —  to develop these machines to the level that they become part of the DOE suite of tools and to access a new area of interaction with matter that hasn’t been addressed before.

The other goal has to do with lasers for defense, lasers for offense and understanding the emergence of lasers from a threat perspective.

It’s very clear that the evolution of lasers is at a turning point right now — that turning point has to do with the ability to make laser photons efficiently using laser diodes much the same as the laser pointer uses laser diodes. You can take those laser diodes and combine them in ways that make very high power and very compact format very efficiently with respect to power from the wall socket to power out of the device. 

This is changing the way that industry makes lasers. It’s changing the way the defense department makes lasers. It presents an entirely new threat with respect to what terrorists might do.  

There isn’t one entity in this country that understands the development of diode-pump lasers, the interaction of diode-pump lasers and the potential threats and countermeasures to diode pump-lasers.

Livermore invented the core technology for these diode-pump laser systems and has all of the computational tools and access to the intelligence community required to basically become the center for the country for understanding laser offense, defense and intelligence applications.

Sometimes people view this area very narrowly as we’re going to build lasers as laser weapons. That is not our job. Our job is to do the R&D that then gets handed over to people to produce weapons systems and to understand enough about those systems and their interactions with matter to be able to provide the knowledge back to the country on how to deal with emerging threats or how to make the systems better for dealing with the problems we face.

In five years the Lab will have the premier gamma ray light source on the planet, if we follow the plan we’re looking at.

That will open up opportunities with respect to the homeland security community, with respect to stockpile surveillance and nuclear energy where we use those light sources to image the isotopic content of different materials in ways that no one has ever been able to do before. Where we actually go in and we say this container has this much of this isotope and that much of the other isotope.

That will be the precursor facility to something that we hope will become a decadal facility for the DOE Office of Science where we build a machine that not only does the imaging tasks and develops all the imaging modalities, but allows fundamental nuclear physics to be studied using photons and using the polarization properties of photons and the tenability of photon sources.

With respect to defense applications in five years, our goal is to have demonstrated capability of three different diode pump laser technologies that the Lab has leadership in: Fiber base technology, at the 100 kilowatt level; solid state laser technology, which we use right now for many of our studies in the lab at the 400 kilowatt level; and then a diode pump alkaline technology, which is receiving a tremendous amount of interest from the DoD at the megawatt scale.

If we do those things correctly, we will not only enable those two missions but we will leave ourselves in a position to address completely new missions that will emerge in DOE having to do with laser-based particle acceleration and how the next generation of high-energy physics machines will be built; based on lasers driving the electrons or the protons and not microwaves.