Theoretical Computational Experimental

1. MIT work plan for fast electron stopping in dense and astrophysical plasmas and in DD/DT ice1 October 2004–30 September 2005 Theoretical Computational Experimental

2. Recent work has modeled energy transfer and scattering of energetic electrons in dense, hydrogenic plasma • e->e scattering is comparable • to e->i scattering • A simplified Møller (e->e) • cross section is obtained • Electron linear energy • transfer in a plasma is • enhanced, and penetration • is reduced, by multiple • scattering 1 MeV e 300 g/cc 5 keV To be published in Phys. Rev. E October, 2004, Li and RP

3. Extensions of Theoretical Work (Li) • Analytic modeling of the electron longitudinal and lateral distributions ( i.e straggling and beam divergence effects) • Study the differences between electron scattering and energy deposition in dense and tenuous plasmas (i.e. relativistic astrophysical jets), and in D2 and DT ice. • Using energy desposition calculations, calculate the preheat from hot electrons in D2 and DT ice.

4. Computational (Cliff Chen, graduate st.) • Develop a Monte Carlo code for simulating the interactions of fast electrons with dense hydrogenic plasmas and D2 and DT ice. • Use simulations to validate the interaction physics described by the analytic models. • Perform simulations to aid in the design, and demonstrate relevance and feasibility, of experiments for testing analytic and numerical models.

5.   100-1000 mm Source Collimator Cryogenic D2 SBD Detectors Experimental concept of the electron scattering and energy deposition in D2 ice

6. Experimental • Use preliminary analytic and Monte-Carlo calculations to design the experiments • Determine the characteristics of a suitable electron accelerator and/or electron-emitting radioactive source • Determine the optimal detector(s) for performing the experiments