A Scaled Beam-Combining Experiment for Heavy Ion Inertial Fusion
Abstract
Transverse beam combining is a cost-saving option employed in many designs for heavy ion fusion drivers. However, the resultant transverse phase space dilution, caused predominantly by anharmonic space charge forces, must be minimized so as not to sacrifice focusability at the target. A prototype combining experiment has been built at LBNL employing the MBE-4 injector at 160 keV and four new Cs^+, 5-mA sources. The ion sources and downstream electrostatic focusing system channel are angled toward a common center so that upon exit the beams merge with as small a footprint as possible. The focusing elements upstream of the merge consist of four quadrupoles and a final combined-function element (quadrupole & dipole). Following the merge, the resultant single beam is transported in a single channel of the 30-period, MBE-4 FODO lattice where emittance growth due to merging, as well as the subsequent evolution of the distribution function, can be diagnosed. Details of the combiner design, PIC simulation predictions, and preliminary results from the experiment will be presented.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- November 1996
- Bibcode:
- 1996APS..DPP..5S07S