The role of spatial and temporal radiation deposition in inertial fusion chambers: the case of HiPER¿

The first wall armour for the reactor chamber of HiPER will have to face short energy pulses of 5 to 20 MJ mostly in the form of x-rays and charged particles at a repetition rate of 5–10 Hz. Armour material and chamber dimensions have to be chosen to avoid/minimize damage to the chamber, ensuring the proper functioning of the facility during its planned lifetime. The maximum energy fluence that the armour can withstand without risk of failure, is determined by temporal and spatial deposition of the radiation energy inside the material. In this paper, simulations on the thermal effect of the radiation–armour interaction are carried out with an increasing definition of the temporal and spatial deposition of energy to prove their influence on the final results. These calculations will lead us to present the first values of the thermo-mechanical behaviour of the tungsten armour designed for the HiPER project under a shock ignition target of 48 MJ. The results will show that only the crossing of the plasticity limit in the first few micrometres might be a threat after thousands of shots for the survivability of the armour

Systems modeling for laser IFE

A systems model of a laser-driven IFE power plant is being developed to assist in design trade-offs and optimization. The focus to date has been on modeling the fusion chamber, blanket and power conversion system. A self-consistent model has been developed to determine key chamber and thermal cycle parameters (e.g., chamber radius, structure and coolant temperatures, cycle efficiency, etc.) as a function of the target yield and pulse repetition rate. Temperature constraints on the tungsten armor, ferritic steel wall, and structure/coolant interface are included in evaluating the potential design space. Results are presented for a lithium cooled first wall coupled with a Brayton power cycle

Impact of magnetic diversion on laser IFE reactor design and performance

This paper covers the results of a scoping study to assess the possible application of magnetic diversion to a laser IFE reactor. Its impact on the engineering design and performance of the reactor is discussed, key issues are identified, and the findings from this assessment are summarized

R and D plan for addressing the thermomechanical behavior of lithium ceramic and Beryllium pebble beds in fusion blankets

Several blanket designs based on lithium ceramic and Beryllium pebble beds are currently considered for fusion reactors. The engineering lay-out of these designs can only be confidently done if models are developed that predict the thermal and mechanical behavior of the pebble beds under fusion boundary conditions, in particular because it is impossible to create a large set of in-pile experimental data reflecting such conditions. Modelling of the pebble bed is complicated by the fact that there is a large number of parameters to be considered. The present report gives an account of the parameters determining the thermomechanical pebble bed behavior. It describes the current status of modelling and experiments used to develop models. On this background, the report identifies issues in modelling that need to be addressed by future research, and suggests a strategy for the modelling steps needed to reach a position where the thermomechanical performance of pebble beds in blankets can be predicted with confidence for the complete range of operating conditions. (orig.)Available from TIB Hannover: ZA 5141(6692) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman