Record Breaking Petawatt Laser Being Built at Lawrence Livermore National Lab

Lawrence Livermore National Laboratory (LLNL; Livermore, CA) has installed and commissioned the highest-peak-power laser-diode arrays in the world, which in total produce a peak power of 3.2 MW. The diode arrays, which were developed and fabricated by Lasertel (Tucson, AZ), will act as the primary pump source for the High-Repetition-Rate Advanced Petawatt Laser System (HAPLS), currently under construction at LLNL. When completed, the HAPLS laser system will be installed at the European Union’s Extreme Light Infrastructure (ELI) Beamlines facility, which is under construction in the Czech Republic. The HAPLS is being built and commissioned at LLNL and will be installed and integrated into the ELI Beamlines facility starting in 2017.

HAPLS is designed to be capable of generating 30 fs pulses with peak powers greater than a petawatt at a repetition rate of 10 Hz. The high repetition rate is possible because, unlike existing petawatt lasers, which are flashlamp-pumped, HAPLS is pumped by diode arrays capable of delivering kilojoule pulses at high repetition rates to the final power amplifier.

Each laser-diode array supplied by Lasertel supplied contains multiple 888 nm laser-diode bars mounted on water-cooled stacks (see figure). The array operates at a brightness of 10 kW/cm2, which Lasertel notes is a world record, at a repetition frequency of 10 Hz. Each array operates at a total peak power of 800 kW, with four such arrays combined and used as the primary pump sources for the HAPLS laser. More than 500,000 combined laser diode emitters combine to produce the total diode optical input power of 3.2 MW.

link.

Livermore National Lab Builds 3.2 MW Laser Module for Czech Republic High-Repetition-Rate Advanced Petawatt Laser System

The US Lawrence Livermore National Laboratory (LLNL) has installed and commissioned an array of laser diodes with a peak power of 3.2MW. The diode arrays are a key component of the High-Repetition-Rate Advanced Petawatt Laser System (HAPLS). When completed, HAPLS will be installed in the European Union's Extreme Light Infrastructure (ELI) Beamlines facility in the Czech Republic.

HAPLS is designed to generate peak powers of more than 1PW (1015W) at a repetition rate of 10Hz and with each pulse lasting 30fs.To develop these diode arrays, LLNL partnered with Lasertel, a developer of high-powered semiconductor laser pump modules, which combined advanced semiconductor laser technology with novel micro optics.

"We are thrilled to be working with LLNL, which continues to push the boundaries for high-energy laser systems," said Lasertel president Mark McElhinney. "Our collaboration has enabled several new benchmarks for laser performance to be set in a remarkably short period of time.

link.

IBM Wins Two Supercomputer Contracts Worth $325 Million

In a Department of Energy deal worth $325 million, IBM will build two massive supercomputers called Sierra and Summit that combine a new supercomputing approach from Big Blue with Nvidia processing accelerators and Mellanox high-speed networking.

The companies and US government agency announced the deal on Friday ahead of a twice-yearly supercomputing conference that begins Monday. The show focuses on the high-end systems -- sometimes as large as a basketball court -- that are used to calculate car aerodynamics, detect structural weaknesses in airplane designs and predict the performance of new drugs.

The funds will pay for two machines, one for civilian research at the Oak Ridge National Laboratory in Tennessee and one for nuclear weapons simulation at the Lawrence Livermore National Laboratory in California. They'll each clock in with a peak performance surpassing 100 petaflops -- that's a quadrillion calculations per second as measured in the Top500 list that ranks the world's fastest machines. Trying to do that with modern laptops would take something like 3 million of them, Nvidia estimates.

link.

LLNL's National Ignition Facility Used to Compress Diamond, Simulate Interior of Jupiter

Lawrence Livermore scientists for the first time have experimentally re-created the conditions that exist deep inside giant planets, such as Jupiter, Uranus and many of the planets recently discovered outside our solar system.

Researchers can now re-create and accurately measure material properties that control how these planets evolve over time, information essential for understanding how these massive objects form. This study focused on carbon, the fourth most abundant element in the cosmos (after hydrogen, helium and oxygen), which has an important role in many types of planets within and outside our solar system. The research appears in the June 17 edition of the journal, Nature.

Using the largest laser in the world, the National Ignition Facility at Lawrence Livermore National Laboratory, teams from the Laboratory, University of California, Berkeley and Princeton University squeezed samples to 50 million times Earth's atmospheric pressure, which is comparable to the pressures at the center of Jupiter and Saturn. Of the 192 lasers at NIF, the team used 176 with exquisitely shaped energy versus time to produce a pressure wave that compressed the material for a short period of time. The sample – diamond – is vaporized in less than 10 billionths of a second.

Though diamond is the least compressible material known, the researchers were able to compress it to an unprecedented density greater than lead at ambient conditions.

"The experimental techniques developed here provide a new capability to experimentally reproduce pressure–temperature conditions deep in planetary interiors," said Ray Smith, LLNL physicist and lead author of the paper.

Such pressures have been reached before, but only with shock waves that also create high temperatures – hundreds of thousands of degrees or more – that are not realistic for planetary interiors. The technical challenge was keeping temperatures low enough to be relevant to planets. The problem is similar to moving a plow slowly enough to push sand forward without building it up in height. This was accomplished by carefully tuning the rate at which the laser intensity changes with time.

link.

DARPA Takes First SFnal Steps to Scalzi's BrainPals

DARPA has selected two universities to initially lead the agency’s Restoring Active Memory (RAM) program, which aims to develop and test wireless, implantable “neuroprosthetics” that can help servicemembers, veterans, and others overcome memory deficits incurred as a result of traumatic brain injury (TBI) or disease.

The University of California, Los Angeles (UCLA), and the University of Pennsylvania (Penn) will each head a multidisciplinary team to develop and test electronic interfaces that can sense memory deficits caused by injury and attempt to restore normal function. Under the terms of separate cooperative agreements with DARPA, UCLA will receive up to $15 million and Penn will receive up to $22.5 million over four years, with full funding contingent on the performer teams successfully meeting a series of technical milestones. DARPA also has a cooperative agreement worth up to $2.5 million in place with Lawrence Livermore National Laboratory to develop an implantable neural device for the UCLA-led effort.

“The start of the Restoring Active Memory program marks an exciting opportunity to reveal many new aspects of human memory and learn about the brain in ways that were never before possible,” said DARPA Program Manager Justin Sanchez. “Anyone who has witnessed the effects of memory loss in another person knows its toll and how few options are available to treat it. We’re going to apply the knowledge and understanding gained in RAM to develop new options for treatment through technology.”

link.

Livermore & MIT Create Ultra Light, Ultra Stiff 3D Printed Material

Imagine a material with the same weight and density as aerogel -- a material so light it's called 'frozen smoke' -- but with 10,000 times more stiffness. This material could have a profound impact on the aerospace and automotive industries as well as other applications where lightweight, high-stiffness and high-strength materials are needed.

Lawrence Livermore and Massachusetts Institute of Technology (MIT) researchers have developed a material with these properties using additive micro-manufacturing processes. The research team's findings are published in a June 20 article in the journal Science.

Titled "Ultralight, Ultrastiff Mechanical Metamaterials," the article describes the team's development of micro-architected metamaterials -- artificial materials with properties not found in nature -- that maintain a nearly constant stiffness per unit mass density, even at ultralow density. Materials with these properties could someday be used to develop parts and components for aircraft, automobiles and space vehicles.

Most lightweight cellular materials have mechanical properties that degrade substantially with reduced density because their structural elements are more likely to bend under applied load. The team's metamaterials, however, exhibit ultrastiff properties across more than three orders of magnitude in density.

"These lightweight materials can withstand a load of at least 160,000 times their own weight," said LLNL Engineer Xiaoyu "Rayne" Zheng, lead author of the Science article. "The key to this ultrahigh stiffness is that all the micro-structural elements in this material are designed to be over constrained and do not bend under applied load."

The observed high stiffness is shown to be true with multiple constituent materials such as polymers, metals and ceramics, according to the research team's findings.

"Our micro-architected materials have properties that are governed by their geometric layout at the microscale, as opposed to chemical composition," said LLNL Engineer Chris Spadaccini, corresponding author of the article, who led the joint research team. "We fabricated these materials with projection micro-stereolithography."

This additive micro-manufacturing process involves using a micro-mirror display chip to create high-fidelity 3D parts one layer at a time from photosensitive feedstock materials. It allows the team to rapidly generate materials with complex 3D micro-scale geometries that are otherwise challenging or in some cases, impossible to fabricate.

"Now we can print a stiff and resilient material using a desktop machine," said MIT professor and key collaborator Nicholas Fang. "This allows us to rapidly make many sample pieces and see how they behave mechanically."

The team was able to build microlattices out of polymers, metals and ceramics.

link.

Livermore National Lab Using Simulation Expertise to Improve Selective Laser Melting

Lawrence Livermore National Laboratory researchers have developed a new and more efficient approach to a challenging problem in additive manufacturing -- using selective laser melting, namely, the selection of appropriate process parameters that result in parts with desired properties.

Selective laser melting (SLM) is a powder-based, additive manufacturing process where a 3D part is produced, layer by layer, using a high-energy laser beam to fuse the metal powder particles. Some SLM applications require parts that are very dense, with less than 1 percent porosity, as the pores or voids are the weakest part of the material and most likely would result in failure.

But building functional parts and components to specific standards and performance specifications can be challenging because a large number of parameters must be set appropriately. Some of the key parameters include laser power, laser speed, distance between laser scan lines, scanning strategy and powder layer thickness. As a result, there is a need for a reliable and cost effective approach to determine the right parameters to develop parts with desired properties, such as high density.

LLNL researchers have developed an efficient approach, based on simple simulations and experiments, to identify optimal parameters to print 3D high-density metal parts. Their work, titled "Density of additively-manufactured, 316L SS parts using laser powder-bed fusion at powers up to 400W" was recently published in the International Journal of Advanced Manufacturing Technology.

The paper explains how parameters for higher-power SLM machines can be selected by using simple, computational simulations to explore the process parameter space. These simulations are used to compute the dimensions of the melt pool, which is the pool of liquid formed when the laser melts the metal powder particles.

link.

Break Even Energy Output Exceeded Four Times at LLNL's National Ignition Facility Since September

Fuel gain exceeding unity in an inertially confined fusion implosion

Authors:

Hurricane et al

Abstract:

Ignition is needed to make fusion energy a viable alternative energy source, but has yet to be achieved. A key step on the way to ignition is to have the energy generated through fusion reactions in an inertially confined fusion plasma exceed the amount of energy deposited into the deuterium–tritium fusion fuel and hotspot during the implosion process, resulting in a fuel gain greater than unity. Here we report the achievement of fusion fuel gains exceeding unity on the US National Ignition Facility using a ‘high-foot’ implosion method which is a manipulation of the laser pulse shape in a way that reduces instability in the implosion. These experiments show an order-of-magnitude improvement in yield performance over past deuterium–tritium implosion experiments. We also see a significant contribution to the yield from α-particle self-heating and evidence for the ‘bootstrapping’ required to accelerate the deuterium–tritium fusion burn to eventually ‘run away’ and ignite.

Livermore Study Ties Precipitation and Global Warming Changes

The rain in Spain may lie mainly on the plain, but the location and intensity of that rain is changing not only in Spain but around the globe.

A new study by Lawrence Livermore National Laboratory scientists shows that observed changes in global (ocean and land) precipitation are directly affected by human activities and cannot be explained by natural variability alone. The research appears in the Nov. 11 online edition of the Proceedings of the National Academy of Sciences.

Emissions of heat-trapping and ozone-depleting gases affect the distribution of precipitation through two mechanisms. Increasing temperatures are expected to make wet regions wetter and dry regions drier (thermodynamic changes); and changes in atmospheric circulation patterns will push storm tracks and subtropical dry zones toward the poles.

"Both these changes are occurring simultaneously in global precipitation and this behavior cannot be explained by natural variability alone," said LLNL's lead author Kate Marvel. "External influences such as the increase in greenhouse gases are responsible for the changes."

The team compared climate model predications with the Global Precipitation Climatology Project's global observations, which span from 1979-2012, and found that natural variability (such as El Niños and La Niñas) does not account for the changes in global precipitation patterns. While natural fluctuations in climate can lead to either intensification or poleward shifts in precipitation, it is very rare for the two effects to occur together naturally.

"In combination, manmade increases in greenhouse gases and stratospheric ozone depletion are expected to lead to both an intensification and redistribution of global precipitation," said Céline Bonfils, the other LLNL author. "The fact that we see both of these effects simultaneously in the observations is strong evidence that humans are affecting global precipitation."

Marvel and Bonfils identified a fingerprint pattern that characterizes the simultaneous response of precipitation location and intensity to external forcing.

link.

LLNL NIF: There was Probably Break Even Fusion, but...

One unintended effect of the U.S. federal shutdown is that helpful press officers at government labs are not available to provide a reality check to some of the wilder stories that can catch fire on the Internet. They would have come in handy this week, when a number of outlets jumped on a report on the BBC News website. The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory in California, it reported, had passed a "nuclear fusion milestone." NIF uses the world's highest energy laser system to crush tiny pellets containing a form of hydrogen fuel to enormous temperature and pressure. The aim is to get the hydrogen nuclei to fuse together into helium atoms, releasing energy.

The BBC story reported that during one experiment last month, "the amount of energy released through the fusion reaction exceeded the amount of energy being absorbed by the fuel - the first time this had been achieved at any fusion facility in the world." This prompted a rush of even more effusive headlines proclaiming the "fusion breakthrough." As no doubt NIF's press officers would have told reporters, the experiment in question certainly shows important progress, but it is not the breakthrough everyone is hoping for.

A memo sent out on 29 September to collaborating labs from NIF Director Ed Moses—which has been seen by Science—describes a fusion shot that took place at 5:15 a.m. on 28 September. It produced 5x1015 neutrons, 75% more than any previous shot. Neutrons are a product of fusion reactions, so they are used as a measure of success.

[...]

One requirement for ignition is that energy output should exceed the energy input from the laser, i.e., that gain (output divided by input) should be greater than 1. NIF's laser input of 1.8 MJ is roughly the same as the kinetic energy of a 2-tonne truck traveling at 160 km/h (100 miles/h). The output of the reaction—14 kJ—is equivalent to the kinetic energy of a baseball traveling at half that speed. Numerically speaking, the gain is 0.0077. The experiment “is a good and necessary step, but there is a long way to go before you have energy for mankind,” Campbell says.

link.

BBC Report: Livermore's National Ignition Facility Has Broken Even

Harnessing fusion - the process that powers the Sun - could provide an unlimited and cheap source of energy.

But to be viable, fusion power plants would have to produce more energy than they consume, which has proven elusive.

Now, a breakthrough by scientists at the National Ignition Facility (NIF) could boost hopes of scaling up fusion.

NIF, based at Livermore in California, uses 192 beams from the world's most powerful laser to heat and compress a small pellet of hydrogen fuel to the point where nuclear fusion reactions take place.

The BBC understands that during an experiment in late September, the amount of energy released through the fusion reaction exceeded the amount of energy being absorbed by the fuel - the first time this had been achieved at any fusion facility in the world.

This is a step short of the lab's stated goal of "ignition", where nuclear fusion generates as much energy as the lasers supply. This is because known "inefficiencies" in different parts of the system mean not all the energy supplied through the laser is delivered to the fuel.

But the latest achievement has been described as the single most meaningful step for fusion in recent years, and demonstrates NIF is well on its way towards the coveted target of ignition and self-sustaining fusion.

For half a century, researchers have strived for controlled nuclear fusion and been disappointed. It was hoped that NIF would provide the breakthrough fusion research needed.

link.

Comet Impacts Necessary for Formation of Life Precursors?

A group of international scientists including a Lawrence Livermore National Laboratory researcher have confirmed that life really could have come from out of this world.

The team shock compressed an icy mixture, similar to what is found in comets, which then created a number of amino acids – the building blocks of life. The research appears in advanced online publication Sept. 15 on the Nature Geosciences journal website.

This is the first experimental confirmation of what LLNL scientist Nir Goldman first predicted in 2010 and again in 2013 using computer simulations performed on LLNL's supercomputers, including Rzcereal and Aztec.

Goldman's initial research found that the impact of icy comets crashing into Earth billions of years ago could have produced a variety of prebiotic or life-building compounds, including amino acids. Amino acids are critical to life and serve as the building blocks of proteins. His work predicted that the simple molecules found in comets (such as water, ammonia, methanol and carbon dioxide) could have supplied the raw materials, and the impact with early Earth would have yielded an abundant supply of energy to drive this prebiotic chemistry.

In the new work, collaborators from Imperial College in London and University of Kent conducted a series of experiments very similar to Goldman's previous simulations in which a projectile was fired using a light gas gun into a typical cometary ice mixture. The result: Several different types of amino acids formed.

"These results confirm our earlier predictions of impact synthesis of prebiotic material, where the impact itself can yield life-building compounds," Goldman said. "Our work provides a realistic additional synthetic production pathway for the components of proteins in our solar system, expanding the inventory of locations where life could potentially originate."

Comets are known to harbor simple ices and the organic precursors of amino acids. Glycine – the simplest amino acid – was recently confirmed to be present in comet Wild-2.

Goldman's original work used molecular dynamics simulations to show that shock waves due to planetary impact passing into representative comet mixtures could theoretically drive amino acid synthesis. This synthetic mechanism could yield a wide variety of prebiotic molecules at realistic impact conditions, independent of the external features or pre-existing chemical environment on a planet.

"These results present a significant step forward in our understanding of the origin of the building blocks of life," Goldman said.

link.

Livermore and UC Santa Cruz Develop Carbon Sequestration Technique In Lab Which Helps De-Acidify Ocean Water

Lawrence Livermore scientists have discovered and demonstrated a new technique to remove and store atmospheric carbon dioxide while generating carbon-negative hydrogen and producing alkalinity, which can be used to offset ocean acidification.

The team demonstrated, at a laboratory scale, a system that uses the acidity normally produced in saline water electrolysis to accelerate silicate mineral dissolution while producing hydrogen fuel and other gases. The resulting electrolyte solution was shown to be significantly elevated in hydroxide concentration that in turn proved strongly absorptive and retentive of atmospheric CO2.

Further, the researchers suggest that the carbonate and bicarbonate produced in the process could be used to mitigate ongoing ocean acidification, similar to how an Alka Seltzer neutralizes excess acid in the stomach.

"We not only found a way to remove and store carbon dioxide from the atmosphere while producing valuable H2, we also suggest that we can help save marine ecosystems with this new technique," said Greg Rau, an LLNL visiting scientist, senior scientist at UC Santa Cruz and lead author of a paper appearing this week (May 27) in the Proceedings of the National Academy of Sciences.

When carbon dioxide is released into the atmosphere, a significant fraction is passively taken up by the ocean forming carbonic acid that makes the ocean more acidic. This acidification has been shown to be harmful to many species of marine life, especially corals and shellfish. By the middle of this century, the globe will likely warm by at least 2 degrees Celsius and the oceans will experience a more than 60 percent increase in acidity relative to pre-industrial levels. The alkaline solution generated by the new process could be added to the ocean to help neutralize this acid and help offset its effects on marine biota. However, further research is needed, the authors said.

"When powered by renewable electricity and consuming globally abundant minerals and saline solutions, such systems at scale might provide a relatively efficient, high-capacity means to consume and store excess atmospheric CO2 as environmentally beneficial seawater bicarbonate or carbonate," Rau said. "But the process also would produce a carbon-negative 'super green' fuel or chemical feedstock in the form of hydrogen."

Most previously described chemical methods of atmospheric carbon dioxide capture and storage are costly, using thermal/mechanical procedures to concentrate molecular CO2 from the air while recycling reagents, a process that is cumbersome, inefficient and expensive.

"Our process avoids most of these issues by not requiring CO2 to be concentrated from air and stored in a molecular form, pointing the way to more cost-effective, environmentally beneficial, and safer air CO2 management with added benefits of renewable hydrogen fuel production and ocean alkalinity addition," Rau said.

Interesting.  Will it scale and deal with real world scenarios?  It almost sounds too good to be true...

The American Inertial Confinement Fusion Roadmap

Inertial fusion energy could have a bright future, despite the failure of the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL; Livermore, CA) to ignite a fusion target by the target date of Sept. 30, 2012, says a National Research Council (NRC) report issued Feb. 20, 2013. The panel writes that the potential benefits of inertial fusion—including a carbon-free energy generation without the fuel limitations or large volume of high-level radioactive waste from fission—“justify it as part of the long-term U.S. energy R&D portfolio.” But that’s going to take time, and commercial inertial-fusion reactors are decades away.

The immediate priority is resolving why the giant laser at LLNL failed to achieve ignition with indirect-drive targets despite delivering pulses that theoretical models of the process predicted would be sufficient. Doing that and modifying NIF and targets to optimize performance “will likely take significantly more than a year,” the panel wrote. They also want to test direct-drive fusion at full NIF power. And they say that now is too early to make a final decision among technologies competing for use in an inertial-fusion energy demonstration.

Proposed Cure for the NIF Fusion Problems: Focusing (sorta)

For several decades, researchers have been using the world’s most powerful lasers to try to recreate the fusion reaction that occurs in stars. The process, called inertial confinement fusion (ICF), uses multiple laser beams to compress and heat a small, spherical target containing nuclear fuel, in order to ignite thermonuclear fusion. In principle, the heat released from the reaction could provide an alternative energy source, but the challenges to achieving ignition are many. One, in particular, is to understand and control a process first identified in the mid-1990s  called crossed-beam energy transfer (CBET), in which the laser beams exchange energy with each other as they overlap in the plasma. In laser-driven fusion experiments, CBET occurs just before the laser beams deposit their energy into the target. The effect can therefore modify the finely tuned symmetry of the beams or cause energy to leak out of the target.

Now, Igor Igumenshchev from the Laboratory for Laser Energetics at the University of Rochester in New York and colleagues are proposing a new technique to mitigate the negative effects of CBET. In Physical Review Letters, Igumenshchev et al. use simulations to show that dynamically reducing—or “zooming”—the spot size of the lasers as they interact with the target would reduce energy transfer between the beams, without disrupting the symmetry of the laser illumination—a negative side effect of some existing proposals for correcting CBET.

The CBET process is relatively simple to explain. When two laser beams overlap in a plasma [ed. see above], they create a beat wave. Free charges in the plasma accumulate where the beat wave’s electric field is weakest (a result of what is known as the ponderomotive force) and this accumulation of charges modulates the refractive index, in effect creating a Bragg diffraction grating for the lasers. Because this grating is created by the beat wave, the Bragg condition is, by construction, always satisfied. Moreover, if there is a wavelength separation between the laser beams, or the plasma flows, the grating can move at (or close to) the speed of sound. The moving grating will then scatter light from one beam in the exact direction of the other beam, effectively transferring energy from one laser beam to the other.

[...]

What the Rochester group is proposing now [6] may prove to be an even more effective way of controlling CBET than simply reducing the laser spot size. Igumenshchev et al.’s key insight is that the negative effects of CBET and radiation asymmetry occur at different times during the target’s implosion. The symmetry of the laser illumination is crucial in the first few nanoseconds after the lasers interact with the target, when nonuniformities can drive low-frequency perturbations on the surface of the spherical target, which grow as it implodes and reduce the implosion performance. At later times, though, the plasma corona has sufficiently expanded to smooth out radiation nonuniformities. But it also offers a favorable terrain for CBET to occur. Igumenshchev et al.’s proposal is to drive the first few nanoseconds of the laser pulse with large spots that are roughly the same diameter as the size of the target; then, at later times, switch to spot sizes that are ∼30–40% smaller, in order to reduce CBET and maintain good energy coupling to the target. The authors show, using 2D hydrodynamics simulations, that tailoring the spot size in this way yields an implosion performance that is almost as good as the ideal case: a purely spherically symmetric implosion.

How would this tuning of the spot size be achieved in practice? The authors imagine a new type of optical element called a “zooming phase plate,” which would produce a different spot size depending on whether a laser lands on the central part of the plate or the outer edges. With such a plate, it would be possible to send two consecutive laser pulses toward the plasma: a first pulse that hits only the outer area of the plate and produces a large spot on the target, and a second pulse that covers the center of the plate and produces a 30–40% smaller spot on the target.

A New Supercomputer Record Set: More Than One Million Cores Used for a Simulation

Researchers at Lawrence Livermore National Laboratory have performed record simulations using all 1,572,864 cores of Sequoia, the largest supercomputer in the world. Sequoia, based on IBM BlueGene/Q architecture, is the first machine to exceed one million computational cores. It also is No. 2 on the list of the world's fastest supercomputers, operating at 16.3 petaflops (16.3 quadrillion floating point operations per second).

The simulations are the largest particle-in-cell (PIC) code simulations by number of cores ever performed. PIC simulations are used extensively in plasma physics to model the motion of the charged particles, and the electromagnetic interactions between them, that make up ionized matter. High performance computers such as Sequoia enable these codes to follow the simultaneous evolution of tens of billions to trillions of individual particles in highly complex systems.

Frederico Fiuza, a physicist and Lawrence Fellow at LLNL, performed the simulations in order to study the interaction of ultra-powerful lasers with dense plasmas in a proposed method to produce fusion energy, the energy source that powers the sun, in a laboratory setting. The method, known as fast ignition, uses lasers capable of delivering more than a petawatt of power (a million billion watts) in a fraction of a billionth of a second to heat compressed deuterium and tritium (DT) fuel to temperatures exceeding the 50 million degrees Celsius needed to initiate fusion reactions and release net energy. The project is part of the U.S. Department of Energy's Office of Fusion Energy Science Program.

This method differs from the approach being taken by LLNL's National Ignition Facility to achieve thermonuclear ignition and burn. NIF's approach is called the "central hot spot" scenario, which relies on simultaneous compression and ignition of a spherical fuel capsule in an implosion, much like in a diesel engine. Fast ignition uses the same hardware as the hot spot approach but adds a high-intensity, ultrashort-pulse laser as the "spark" that achieves ignition.

The code used in these simulations was OSIRIS, a PIC code that has been developed over more than 10 years in collaboration between the University of California, Los Angeles and Portugal's Instituto Superior Técnico. Using this code, Fiuza demonstrated excellent scaling in parallel performance of OSIRIS to the full 1.6 million cores of Sequoia. By increasing the number of cores for a relatively small problem of fixed size, what computer scientists call "strong scaling," OSIRIS obtained 75 percent efficiency on the full machine. But when the total problem size was increased, what is called "weak scaling," a 97 percent efficiency was achieved.

"This means that a simulation that would take an entire year to perform on a medium-size cluster of 4,000 cores can be performed in a single day. Alternatively, problems 400 times greater in size can be simulated in the same amount of time," Fiuza said. "The combination of this unique supercomputer and this highly efficient and scalable code is allowing for transformative research."

OSIRIS is routinely used for fundamental science during the test phase of Sequoia in simulations with up to 256,000 cores. These simulations are allowing researchers, for the first time, to model the interaction of realistic fast-ignition-scale lasers with dense plasmas in three dimensions with sufficient speed to explore a large parameter space and optimize the design for ignition. Each simulation evolves the dynamics of more than 100 billion particles for more than 100,000 computational time steps. This is approximately an order of magnitude larger than the previous largest simulations of fast ignition.

Cray to Provide Petaflop System to LANL/NNSA Labs

Global supercomputer leader Cray Inc. (NASDAQ: CRAY) today announced that it has signed a sub-contract with Los Alamos National Security, LLC to provide the National Nuclear Security Administration (NNSA) with a next-generation Cray supercomputer. Currently valued at more than $45 million, the multi-year, multi-phase contract can be expanded if the NNSA exercises an option for a future upgrade. The new system will create a new supercomputing platform, named Cielo, for the Advanced Simulation and Computing program at the NNSA.

The Cielo platform will support all three of the NNSA national laboratories, which include Los Alamos National Laboratory, Sandia National Laboratories and Lawrence Livermore National Laboratory. The NNSA will use the new supercomputing system to ensure the safety, security and effectiveness of the United States' nuclear stockpile, and will run the NNSA's largest and most demanding modeling and simulation workload.

"Cielo is being acquired and deployed by the NNSA's New Mexico Alliance for Computing at Extreme Scales (ACES). This is a joint partnership between Los Alamos National Laboratory and Sandia National Laboratories. Both Los Alamos and Sandia have a long history with Cray, going back to the very beginning of the supercomputing era," said John Morrison, High Performance Computing Division Leader at Los Alamos. "With the Cielo platform, that history continues with the next generation of capability computing in support of the U.S. nuclear security enterprise."

"Cielo is the culmination of a two year partnership between Sandia and LANL on ACES," said Sudip Dosanjh, Sandia co-director for ACES. "We look forward to working with Cray to create an order of magnitude increase in capability for key NNSA national security applications. Cielo will target extremely large problems that require production, petascale supercomputing."

"The NNSA plays a critical role in protecting the safety and security of our country, and we are quite proud that some of the organization's most critical scientific research will be done on a Cray supercomputer," said Peter Ungaro, Cray president and CEO. "We have had a great partnership with the NNSA including the development of Red Storm -- a collaboration that enabled the launch of our first Cray XT3 supercomputer. We are honored to be able to continue this important partnership and are encouraged that the NNSA laboratories share in the excitement around our next-generation 'Baker' supercomputer."

The next-generation Cray supercomputer will be housed at the Strategic Computing Complex at the Los Alamos National Laboratory and is expected to be delivered in the second half of 2010. Code-named "Baker," Cray's new supercomputing system will feature a new interconnect chipset known as "Gemini" and enhanced system software that improves the performance, productivity and reliability of the system. Cray's planned "Baker" supercomputer builds on the Cray XT system architecture found in the world's fastest supercomputer and improves it in every key dimension.

no time to comment. I didn't even get a chance to work on the Medea post this weekend.

NIF's AWAY! A Step to the Fusion Drive

Using the most powerful laser system ever built, scientists have brought us one step closer to nuclear fusion power, a new study says.

The same process that powers our sun and other stars, nuclear fusion has the potential to be an efficient, carbon-free energy source—with none of the radioactive waste associated with the nuclear fission method used in current nuclear plants.

Thanks to the new achievement, a prototype nuclear fusion power plant could be operating within a decade, speculated study leader Siegfried Glenzer, a physicist at Lawrence Livermore National Laboratory in California.

Glenzer and colleagues used the world's largest laser array—the Livermore lab's National Ignition Facility—to heat a BB-size fuel pellet to millions of degrees Fahrenheit.

"These lasers are pulsed, and for a very short amount of time"—one ten-billionth of a second—"the power they produce is more than all the power generated by the entire electrical grid of the United States" at any given moment, Glenzer said.

The test confirmed that a technique called inertial fusion ignition could be used to trigger nuclear fusion—the merging of the nuclei of two atoms of, say, hydrogen—which can result in a tremendous amount of excess energy. Nuclear fission, by contrast, involves the splitting of atoms.

The laser demonstration means scientists are now much closer to triggering nuclear fusion in a controlled setting—something that's never been done before and which is necessary if fusion is to be harnessed for energy.

Wow. This is really kewl and damned depressing at the same time. A bit of background is available here.

depressing first. The NIF has waaaaaaaaaaaaaaay over budget. It's waaaaaaaaaaaaaaaaaaay behind schedule. In fact, if not for Shrub, I suspect it would have been canceled even with its supposed place in our testing regime. I know a nontrivial number of physicists, including those in the fusion program, that are annoyed with this: it sucks down money, they feel, is better spent elsewhere.

The damned kewl part is that we'er a step closer to inertial confinement fusion. While probably not the best way to produce power unlike the MHD fusion. However, it is INFINITELY closer to what we need for fusion drives in space. Now, assembling this is space is going to be a stone cold...monster...but once you have, you can get some impressive results for propulsion.

Potential irony here: we could get fusion drives long, long before we get fusion reactors.

Oh, note, maybe there's a reason to get that lunar He3 after all, James.

New Top 500 List

1 Los Alamos National Laboratory
United States Roadrunner (IBM Cell + Opteron System)

2 Oak Ridge National Laboratory
United States Jaguar (Cray XT5)

3 Forschungszentrum Juelich (FZJ)
Germany JUGENE (IBM Blue Gene/P Solution)

4 NASA/Ames Research Center/NAS
United States Pleiades (SGI Altix)

5 Lawrence Livermore National Laboratory
United States BlueGene/L (IBM Blue Gene)

6 National Institute for Computational Sciences/University of Tennessee
United States Kraken (Cray XT5)

7 Argonne National Laboratory
United States (IBM Blue Gene/P)

8 Texas Advanced Computing Center/Univ. of Texas
United States Ranger (SunBlade x6420, Opteron)

9 Lawrence Livermore National Laboratory
United States Dawn (IBM Blue Gene/P)

10 Forschungszentrum Juelich (FZJ)
Germany JUROPA (Bull Sun Constellation)

And we fell to #11 despite our big upgrade and acceptence we just did. Ah well.

(where did the freakin GERMANS come from?! They're making the Japanese look bad!!!)

(oh and sorry about the delay)

Bay Area Scientific Computing Day

The Bay Area Scientific Computing Day (BASCD) is an annual informal gathering to encourage the interaction and collaboration of researchers in the fields of scientific computing and computational science/engineering from the San Francisco Bay Area. This event provides a great venue for junior researchers to present their work to the local community, and for the Bay Area scientific and computational science/engineering communities at large to interchange views on today's multidisciplinary computational challenges and state-of-the-art developments.

This year marks the 10th anniversary of BASCD. For this occasion, Lawrence Berkeley National Laboratory, which organized the first BASCD in 2000, will host the event on site on Saturday, May 9, 2009.

The event will feature presentations by researchers from institutions in the San Francisco Bay Area. There will also be opportunity for poster presentations.

Organizers:

Robert Crockett
Esmond Ng

Administrative Support:

Rachel Lance
Yeen Mankin

Venue

Location: Lawrence Berkeley National Laboratory, Building 66 Auditorium
Date: Saturday, May 9, 2009

Program Agenda

Current Speakers:

* Jim Bremer (UC Davis), "Efficient Discretization of Boundary Integral Equations on Domains with Corners"
* Anwei Chai (Stanford University), "Compressed Sensing and Imaging: A Comparative Study"
* Mark Hoemmen (UC Berkeley), "Communication-avoiding iterative methods"
* Nicole Lemaster (Sandia Lab), "Adaptive Load Balancing for Component-based PDE Solvers"
* Kamesh Madduri (LBNL), "High Performance Computing for Massive Graph Analysis"
* Chris Rycroft (LBNL), "Real-time control of mixing in dense granular flow"
* Mike Singer (LLNL), "TBA"

Poster Presentations:

Those interested in presenting a poster presentation should email Robert Crockett, rkcrockett-at-lbl-dot-gov, by the deadline of April 17. Please include title and abstract. There are a limited number of slots available, and those selected will be notified the following week.

The final agenda will be available soon.

Registration

No registration fees are required for participiation in the Bay Area Scientific Computing Day.

All participants of the Bay Area Scientific Computing Day must register in order to gain site access at Lawrence Berkeley National Laboratory.

Go here to register.

Additional Information

Site Access

All participants must sign up at the registration page in order to visit Lawrence Berkeley National Laboratory and attend the Bay Area Scientific Computing Day.

Directions

The Bay Area Scientific Computing Day will be held in Building 66 Auditorium, which is located at the east end of Lawrence Berkeley National Laboratory. Building 66 is easily accessible from the Strawberry Canyon Gate. A map of Lawrence Berkeley National Laboratory is available.

General information on directions to Lawrence Berkeley National can be found at http://www.lbl.gov/Workplace/Transportation.html.

To get to the Strawberry Canyon Gate from I-80: Click here for directions from Google Map.

To get to the Strawberry Canyon Gate from CA-24: Click here for directions from Google Map.

Weather in Berkeley

Current weather information and forecast can be found at http://www.wunderground.com/US/CA/Berkeley.html.

Previous Bay Area Scientific Computing Days

2000 - Lawrence Berkeley National Laboratory
2001 - Lawrence Livermore National Laboratory
2002 - Sandia National Laboratories, Livermore
2003 - University of San Francisco
2004 - Stanford University
2005 - Lawrence Berkeley National Laboratory
2006 - Lawrence Livermore National Laboratory
2007 - Stanford University
2008 - University of California, Berkeley

A nontrivial amount is HPC. I will probably not be attending because of Team Phoenicia testing, but I strongly encourage people to do so. If you want to network into the HPC/scientific computing world. this is one of the good ways to do so.

Link in the title like always.