In Fast Ignition scheme, each of physics phenomena (e.g., overall radiation- hydrodynamics from implosion to fusion burning, fast electron generation in relativistic laser-plasma interactions, its propagation to dense cores and energy deposition there, and alpha-particle transport) has different time- and space scale and complicatedly interacts one another. Thus, it is required, but practically impossible to simulate all phenomena with one code. In ILE and the related group, hence, Fast Ignition Integrated Interconnecting code project (FI³ project) is in progress, where the each phenomenon is simulated with individual code and the obtained results are integrated.
In the implosion process, a space scale varies in a wide range and considerable deformation of target shell occurs (especially in cone-guided targets). For calculating the overall radiation-hydrodynamics, ALE (Arbitrary Lagrangian Eulerian) algorithm coupled with CIP method has been developed and this method enables the code to capture the detail implosion phenomena. A collective PIC code is used for simulating generation of fast electrons in the relativistic laser-plasma interactions and for evaluating the energy distribution of fast electrons injected into dense cores. In core plasmas, the density reaches more than 10⁴ times solid density at a maximum compression and the collisions between fast electrons and bulk particles become significant. For simulating the fast electron transport and energy deposition process in such dense plasmas, the RFP (Relativistic Fokker-Planck) code has been developed.
In first step of the FI³ project, we carried out "off-line integrated" simulations, i.e. each of processes is separately simulated, and the obtained results are transferred to the other code. First, the ALE radiation-hydro code simulates the implosion process to obtain the core plasma profile at a maximum compression. Using this profile, the collective PIC code evaluates the time-dependent energy distribution of fast electron. Finally, on the basis of a coupled Eulerian hydrodynamics and the RFP code, the core heating and fusion burning processes are simulated using both profiles (bulk plasma and fast electron).
In the conference, we will demonstrate the first results of overall Fast Ignition simulations and discuss the implosion dynamics of a cone-guided target, time-dependent fast electron energy distribution, and core heating profiles.