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ICF & High Energy Density (HED) Research Within the NNSA. Fusion Power Associates Symposium December 2-3, 2010 Washington, DC Dr. Allan A. Hauer Chief Scientist, Stockpile Stewardship Program National Nuclear Security Administration US Dept. of Energy.
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ICF & High Energy Density (HED) Research Within the NNSA Fusion Power Associates Symposium December 2-3, 2010 Washington, DC Dr. Allan A. Hauer Chief Scientist, Stockpile Stewardship Program National Nuclear Security Administration US Dept. of Energy
Three major DOE missions rely on excellence in High Energy Density Physics (HED) for success • National Security • Stockpile Stewardship • Certification with advanced predictive capability validated by sophisticated experiments • Protecting against technological surprise • Maintaining preeminence in HED Science • Fundamental Science • Stewardship of HED • Joint programs with the Office of Science • Cross-cut with materials science mission • Advanced measurements on NIF, Z and potential new capabilities • Energy • Inertial Fusion Energy Sciences energy-related HED • Potential development of advanced fusion concepts with dual use applications
Primary phase Super-critical assembly Primary energy production Energy transfer X-rays transfer energy from primary to secondary HE phase High explosive creates supercritical assembly Secondary phase Secondary produces energy, explosion and radiation Nuclear Phase (UGTs NIF and, Z) Pre-nuclear phase (UGTs, sub-crits, DARHT, JASPER, etc) After the explosive phase, weapons rapidly evolve into the HED and plasma regimes Relevant laboratory expts. are performed throughout the HED phase Weapons operation proceeds through the conditions of planetary interiors, to stellar interiors
High Energy Density Physics is a key discipline underpinning Stockpile Stewardship • Extreme conditions in temperature, density, pressure allow investigation of a large span of physical states. • These extreme conditions are required to meet national security needs but also enable contributions to a broad span of basics physics including astrophysics, materials in extreme conditions and many other sub-disciplines. • Stewardship of HED and plasma science provides essential support for the NNSA mission.
Extraordinary new HED capabilities are now in place • National Ignition Facility (NIF) • Only access to burning plasma conditions • Important mission experiments have already been performed • Omega EP • Sophisticated high irradiance capabilities • Important venue for advanced fusion research • Z Machine • Key venue for materials science measurements • Outstanding new results at 4 Mbar. • Enormous increase in computational power compliments experimental capability
Advanced Materials Science has proved to be a fruitful application for ICF facilities Pulsed power Computational science and experimental science must be integrated from the atomic- to the continuum-level to predict the properties of materials under extreme conditions Continuum e– Microscale Atomic Scale m Lasers Length scales µm Gas Gun DAC nm Experimental platforms 10–4 – 102 s–1 Static 102 – 105 s–1 105 – 109 s–1 Pressure Strain Rates
NNSA mission needs have driven the creation of HEDP environments that are ideal to study complex HED plasmas and materials Rayleigh Taylor Instabilities High Mach Number unstable flows Jets Materials in the Extreme Mass Outflow MHD, thermo-electric, and “anomalous” heating Shocks and radiation transport
NNSA continues to support the advancement of High Energy Density Basic Science • ReNew Workshop Chaired by Prof. Bob Rosner has completed its report • NIF has completed a successful competitive process for identifying basic science projects to be undertaken in the next few years • A new solicitation for HED science proposals will be issued jointly with OFES in 2011. • Office of Science / NNSA Workshop on the research directions for Science on NIF will be held in spring 11.
Proposals Selected in the NIF process spanand exciting spectrum of scientific questions
Proposals Selected in the NIF process spanand exciting spectrum of scientific questions
The pursuit of ignition will dominate the agenda at NIF through 2012 • 3 major series of ignition experiments are planned for 2010-2012. • The plan is to transition to development of an “ignition weapons physics platform” • This “platform” development shares many common goals with energy research • Robust operation, moderate to high gain • The diagnostic suite will be rapidly evolving during this period. • Installation of Neutron imaging began in 2010 • Several beam lines of the ARC backlighting system will be available in 2012. • Detailed burn history measurements were begun in 2010 • Diagnostics that may be unique to the energy mission should be under consideration now. The schedule for the first ignition attempts is somewhat behind the projection presented at the ‘09 FPA meeting
Cryogenically layered (THD) target experiments have begun • X-ray image created from 20-30 frames each taking » 4 sec to capture for » 2 minutes total • Temperature: 18K ±0.001K control • Target position stability for X-ray imaging : < 2 microns • X-ray of THD cryo layer
The achievement of igniting conditions will open new frontiers in plasma research • Plasma temperatures > 20 keV ; compressed densities > 1000 gm / cm2 ;pressures ~ 1 Tbar • The high performance implosions needed for ignition can also be employed in a variety of non-ignition basic science investigations. • Planetary and astro- physics • Materials under extreme conditions • Performing detailed measurements under igniting conditions will present a considerable diagnostic challenge.
The pursuit of ignition will dominate the agenda at NIF through 2012 • Detailed diagnostics that operate during an ignition shot remain a major challenge. Excellent progress has been made in ignition diagnostics to this point. • A successful ignition shot will mandate a 1-2 week suspension of experimental operations at NIF.
Ignition experiments must demonstrate repeatable performance to satisfy both weapons and energy applications • The ultimate “control levels” required for various tuning operations (such as drive symmetry) must be demonstrated i.e. “in practice what are the most sensitive parameters ?” • Can ignition gain levels be controlled through planned variation in laser or target parameters ? • Is there a fundamental “floor” to the variability in gain ? Weapons and energy applications of ignition will require much more than passing the threshold of TN performance
Los Alamos NIF Neutron imager is tested and calibrated on Omega 2 axis / 2 image system will allow simultaneous primary(14-MeV ) and downscattered (10-12 MeV ) imaging. Future testing of NI will likely involve polar direct drive capsules thus advancing both basic science and diagnostic development
Nuclear diagnostics are being developed to enable precision measurements of capsule conditions A double reaction is used to diagnose mix: n + t t* t + shell -> mix β Mix region t+ 9Be Ignited DT fuel Triton + 9Be ablator (t,α) reactions distinguish different types of mix. NIF full Yield - 8Li production No Mix Chunk Mix Atomic Mix 1E12 3E12 1E14 Debris collector & β counter. t+ 9Be -> α + 8Li + β ( 13 MeV, 840 ms)
Inertial Fusion Energy 2010 • Fusion Energy – no carbon dioxide, modest nuclear waste, • 50 years of exploration – ignition imminent at NIF • NAS to provide recommendations on IFE priorities • Timeline and demonstration potentially similar to ITER
User Facilities and Shared National Resources – an important component of the future of NNSA facilities • Strengthening the HED science base is an essential part of the NNSA mission and a responsibility to the nation. • 15% of facility time devoted to basic science is a goal. • Mission oriented work will still dominate the agenda for the foreseeable future. • Uniform policies and procedures will give a clear picture to the international science community and to our sponsors • A broader constituency for our facilities is attractive to substantial segments of congress. Thus far, consideration of basic science (beyond the weapons mission) has been in the general realm of HED
Organizing and planning principles beyond the ignition demonstration • Formulation of the national agenda for HED weapons physics is now well established • 5 Year Plan has been completed – will be continually updated • This will evolve to one of the key source documents for the PCF • Weapons requirements will continue to dominate the agenda at the major NNSA facilities • A close collaboration and cooperation will be formed between NNSA and the DOE Office of Science to formulate the broader scientific agenda(~15% of facility time). • NNSA will provide help to the Office of Science in Preparing for the NAS review of IFE. • Utilization of the major NNSA facilities will be guided by a uniform national policy
After robust ignition is demonstrated, advanced fusion concepts will be considered • Double shell ignition • Many desirable characteristics • Fast ignition • Potentially higher gain • Shock ignition • Direct Drive • Potentially higher gain • Potentially greater physical access to the burning plasma • Operation at 2 w • Potentially > 3 MJ available
ICF and other NNSA Drivers will enable a wide range of “cross cutting” research • Materials science under extreme conditions has a wide spectrum of applications • Fusion materials measurements are another link between weapons requirements and IFE • Laboratory astrophysics on Lasers (NIF and Omega) and Z is a burgeoning field
Pulsed power has had considerable success in advanced materials measurements in addition to its work in fusion 22 MJ stored energy 26 MA peak current 100-300 ns pulse length 300 TW, 3 MJ x-ray source 10-100 Mbar pressures
Advanced materials work on lasers, pulsed power and accelerators links with the IFE mission
NNSA supports HED facilities of varying scale • Large facilities – NIF, OMEGA, Z • Most extreme conditions, complex experimental setups, large operations crews, few hands-on opportunities • Intermediate Scale – Trident, Jupiter, Zebra, … • Modest operations crew, hands-on opportunities • University Scale – Texas Petawatt, OSU high rep. rate, … • Small operations crew, serve as a basic training ground for new students, many hands-on opportunities In many cases, experiments will progress from small to intermediate to large scale facilities Smaller scale work will also continue to play a role in IFE
NNSA relies on intermediate scale plasma science facilities for basic science support • Examples of intermediate size plasma facilities: • Jupiter at LLNL (lasers): support of NIC and NIF; mission; users • Trident at LANL (laser): support of NIF and NIC; mission; users • Texas Petawatt at UTX (laser): discovery-driven research; users • Z-Beamlet / Z Petawatt at SNL (laser): diagnostic for ZR; users • Nevada Terawatt at UNR: pulsed power Intermediate-size plasma facilities provide both direct and indirect mission support, and we are encouraging user access at our intermediate facilities
IFE / interaction points between NNSA and OFES • As data on ignition comes in it will be utilized to guide some aspects of IFE planning • NNSA responsibility to make this information readily available as soon as feasible • OFES will take the lead in some aspects of “advanced ICF” • Shock ignition • Fast ignition • As IFE plans solidify more NNSA facility time for this work may be justified.
The achievement of ignition will provide a significant catalyst to all of HED and IFE in particular It will also present specific challenges – the specific constraints of reliable ignition production Current collaborative interactions between OFES and NNSA are very promising precursors to even stronger collaborations on national challenges such as energy Conclusions
Single 5 Hz FTF beamline engages injected targets 500 kJ FTF Where the Engineering Test Facility might fit in the development path for fusion energy • Stage I:Develop full size components • Laser module (e.g. 17 kJ, 5 Hz KrF beamline) • Target fabrication/injection/tracking • Chamber, optics technologies • Refine target physics • Power plant/FTF design • Stage II 100 MW Engineering Test Facility (ETF) • Demo physics / technologies for a power plant • G: 7 - 10 , G: 100 - 140 • Tritium breeding, power handling • Develop/ validate fusion materials • Operating: ~2025 • Stage III Prototype Power plant(s) • Electricity to the grid • Transitioned to private industry
High energy lasers have been used to extend solid state physics to the 10 Mbar regime Ramp compression shows diamond is stable and strong to 8Mbar Ramp laser intensity to produce shockless compression 8 New cold-solid-state ramp compressed data Pressure (Mbar) 4 Calculated Cold curve Diamond cell data 0 4 5 6 Density (g/cc) • Edwards, et al. (PRL 04) • Smith, et al. (PRL 06) • Bradley, et al. (PRL 08) • Eggert et al. (SCCM 07) Bradley et al NIF designs use the same technique to study solids to many >30 Mbar
High energy lasers have been used to extend solid state physics to the 10 Mbar regime Ramp compression shows diamond is stable and strong to 8Mbar Diffraction for structure & strength =>Fe is HCP to 5 Mbar Fe data at 3 Mbar 8 New cold-solid-state ramp compressed data c Pressure (Mbar) 4 Calculated Cold curve Eggert et al Fe Data at 5 Mbar EXAFS is being used to measure T & structure in Fe to 3 Mbar Diamond cell data 0 4 5 6 Density (g/cc) 3 5 7 9 Bradley et al Electron wavenumber (A-1) NIF designs use the same technique to study solids to many >30 Mbar Hicks et al 32
High Energy Density Physics is the Cornerstone of Science at NIF, Omega and Z
The role of intermediate scale facilities is a crucial planning issue • A consistent picture of the value of intermediate facilities has emerged from the academic community • Value of “hands on” experience in training and education • The need for staging, prototyping and calibration for work at the large facilities. • Finding a funding pattern will be a challenge but a preliminary effort will be attempted