San Diego, California, 17-19 June 2002

Gas Transport and Density Control in the HYLIFE Heavy-Ion Beam Lines

 

Christophe S. Debonnel^1,2, Dale R. Welch³, Simon S. Yu² and Per F. Peterson¹

1. Department of Nuclear Engineering

   University of California

   Berkeley, CA 94720

2. Lawrence Berkeley National Laboratory

   Heavy-Ion Inertial Fusion Virtual National Laboratory

   Berkeley, CA 94720

3. Mission Research Corporation

   Albuquerque, NM 87110

 

The effective propagation and focusing of heavy-ion beams in the final-focus magnet region of heavy-ion inertial fusion chambers requires control of the background gas density and pressure in the tubes. Previous studies have focused on evaluating the amount of ablation debris reaching the entrance of the beam ports. A modified version of the TSUNAMI code has been used to assess the density and temperature of gas debris transported approximately three meters up the beam tubes and reaching the final-fcus magnet region, assuming that the liquid vortexes are perfectly condensing surfaces. Results are presented and compared to a simple, analytical method that estimates the density profile in the beam tubes as a function of time. A new beam line design is described. A magnetic "sweeper" has been envisaged to divert the ablation debris into the liquid vortexes that coat the inside walls of the beam tubes. This sweeper would prevent the hot ablation debris from reaching the magnet region, and conveniently suppress the need for mechanical shutters to reduce debris venting in the final-focus magnet region. The final, pre-shot, density profile in the beam tube is given as well.

 

 

 

Corresponding author:

Christophe S. Debonnel

University of California

4118 Etcheverry Hall

Berkeley, CA 94720

Phone: (510) 642-0421

Fax: (510) 643-9685

CDebonnellbl.gov