A 2013-2020 roadmap towards Inertial Fusion Energy based on a 2007-2012 watching brief Table of content Executive Summary A. Overall evolution of the IFE Research B. Scientific and technological FP7 highlights 1. Laser developments 2. Alternative ignition schemes a. Shock ignition b. Fast ignition α. Electron-driven fast ignition β. Ion-driven fast ignition c. Impact ignition d. Heavy-ion fusion 3. Laser-plasma interaction 4. IFE-relevant basic science 5. Diagnostics 6. Fusion technologies: from targets to materials and power plant systems a. Targets b. Materials c. IFE technologies: reactor chambers and blankets, safety and radio-protection d. Consequences of Different Meteorological Scenarios in the Environmental Impact Assessment of Tritium Release C. FP7 transverse activities 1. Community developments 2. Knowledge diffusion 3. Mobility 4. IFE-MFE synergy D. The IFE roadmap beyond 2013 Mission 1.1 - Acquiring new insights into the basics of ignition physics 1. Atomic Physics 2. Laser-Plasma Interaction 3. Hydrodynamics Mission 1.2 - Demonstrating Shock Ignition on the LMJ Mission 2 - Developing key elements for IFE technologies 1. Laser driver technology 2. Materials 3. IFE technologies: reactor chambers and blankets, safety and radio-protection E. Concluding remarks – Case for continuation of the EURATOM IFE KiT activities and funding 1 Executive summary The Consultative Committee for the EURATOM specific research and training programme in the field of Nuclear Energy (CCE-FU) endorsed in 2007 continuation of the keep-in-touch (KiT) activity over civilian research activities in inertial confinement fusion for energy (IFE), as part of the Annual Work Programmes of the involved Associations. To monitor this KiT activity, the CCE-FU set up the Inertial Fusion Energy Working Group (IFEWG) from whom annual Watching Briefs, as well as in- depth proposals, are requested. IFE is currently not mentioned in the “EFDA roadmap to the realization of fusion energy” motivating the drawing up of the present document. The IFE missions that are described in this document fit naturally into the “Training and education” and “Breaking new frontiers – the need for basic research” sub-programmes. They include acquiring new insights into the basics of ignition physics, demonstrating shock ignition (one of the most credible scheme for fusion energy) on the LMJ as well as exploring other alternative approaches, and keeping watch over scientific and technological developments conducted within other international IFE programs, while ensuring synergies with MFE activities (in material research, radiation protection issues, computational developments, for instance) and efficiently strengthening the overall fusion community,. The FP7 EURATOM KiT activities have resulted in a steadily increasing number of collaborations throughout the participating laboratories in Europe and enabled a strong and fruitful research program across national approaches. It has attracted a significant number of PhD students and excellent young researchers who continue to actively contribute to fusion-relevant scientific developments. Based on its expertise, the IFE working group is convinced that it is mandatory that IFE-oriented research be conducted at a trans-national level to be visible and credible as an alternative road towards sustainable and secure energy source. The following report is first summarizing the work performed under the 7th European Framework Programme from 2007 to 2012 within the EURATOM IFE KiT activities (section B). It takes into account the recommendations issued in January 2010 by the CCE-FU following compulsory adaptation of the fusion programme beyond 2011. It also presents (section D) a European roadmap to the realization of laser fusion energy which completes the EFDA MFE roadmap. 2 A. Overall evolution of the IFE Research Inertial Fusion Energy research is currently enjoying significant developments. The National Ignition Facility (NIF) at LLNL (USA) (figure right) was completed in April 2009. Shortly after its dedication in May 2009, the National Ignition Campaign (NIC) began, conducting shots to first fine- tune the performance of the NIF's lasers (up to 1.85MJ of ultraviolet light), then calibrate the diagnostic equipment (more than 50), and finally implode cryo- layered targets, making steady progress toward achieving indirectly-driven ignition. Ignition-level radiation temperatures, up to 330eV, were reported, shock timing was optimized close to specs but hotspot densities and pressures were kept lower than predicted. 90 % of the predicted implosion velocity was reached but the achieved pressure was insufficient for achieving ignition. Evidence suggested that 3D hydrodynamics is a significant factor affecting performances of current DT implosions through large P4 asymmetry and ablator/fuel mix. The NIC formally ended in September 2012 but the effort to achieve ignition (i.e. α-particle heating of the fuel and burn) on the NIF is further pursued. The proposed strategy is based on (i) focused experiments to improve basic understanding - with the help of improved simulation capabilities - of the complex physics phenomena occurring in a laser- driven implosion (including fundamental physics, i.e. opacities, equations of state, etc) and (ii) integrated implosions to test new understanding, designs and models. A recent review by the National Academy of Sciences strengthens this strategy by concluding that there is no indication that ignition would not be achievable on NIF, that high priority shall continue to be put to target physics programmes on NIF and other facilities and that “so far as target physics is concerned, it is a modest step from NIF scale to IFE scale.” The United States are thus examining the viability of IFE as a clean source of energy and LLNL is developing a Laser Inertial Fusion Energy (LIFE – figure right) baseline design and examining various technology choices for developing a power plant prototype for the next decade. Anticipating a successful demonstration of ignition and gain on NIF and on the Laser MégaJoule (LMJ, which is close to completion, with first light expected end of 2014 – figure right), scientists and engineers from across Europe are developing the case for the next generation laser fusion facility: HiPER (High Power Laser Energy Research Facility). Coordinated by the UK Science and Technology Facilities Council (STFC), the project is a fully-civilian European one, included in the ESFRI Roadmap; it gathers 26 partners from 10 European countries, including almost all the EURATOM IFE keep-in-touch (KiT) partners, with international links to Russia, Japan, South Korea, China and Canada. The HiPER objective is then to address separately (thanks to IFE modularity) all the technological challenges still faced (in terms of target injection, materials, blanket design, heat extraction…) in order to advance on the route to a real laser fusion reactor 3 device and, through a “single-facility build” strategy, demonstrate the potential of Laser Energy (including reliability and availability). After a 2-year conceptual design, the project entered in 2008 a 5-year Preparatory Phase (PP), partly funded by the European Commission, which shaped many aspects of the IFE-relevant research within Europe, and beyond. Numerous studies were conducted to scientifically and technologically support it; they led to reference designs for the laser beam lines, for the target and finally for the facility itself (figure above left), including the fusion chamber (figure above right) and the target injection system. Three operation modes were defined: (i) a burst mode (with bunches of 100 shots including, at max., only 5 DT shots) without any blanket, (ii) a low-power prototype mode and (iii) a full-power reactor demo mode. They led to different chamber designs and allow identifying bottlenecks for a realistic roadmap towards IFE. It has been shown that, to be commercially attractive, (i) the fusion cycle must run at a repetition rate of at least 10 Hz and that a “target gain” (Elaser/Efusion) close to 100 is required, (ii) diode-pumped solid-state laser (DPSSL) technology and alternative ignition schemes may fulfil such requirements. These so-called alternative schemes rely on decoupling direct drive target compression from fuel heating - and thus ignition – using an “external” match, a laser-launched strong shock (for the shock ignition scheme which will be programmatically studied in the following years), or a laser- accelerated ultra-fast particle beam (for the fast ignition scheme which has been extensively studied in the past but still requires validation). It is worth noticing that these scientific studies were financed at the national level or through European initiatives, such as the LASERLAB-Europe I3 and the EURATOM IFE KiT programme, but not on PP funds which were devoted to “integration” activities. Europe is highly advanced in the strongly competitive ICF/IFE research and shall not lose its expertise (evidenced for instance by the highlights reported in section B). The HiPER PP ending on April 2013, and the EURATOM FP7+2 programme at the end of this year, it will now enter a new phase, complying with a shared roadmap (presented in section D) within the Horizon2020 programme, and mainly based on national initiatives. Actually, there will be - for the moment - no research and development program that will integrate the whole range of technologies and sciences required to demonstrate the viability of IFE, which undoubtedly