ULF generated by a satellite-emitted beam

The work reported under this contract was motivated by the need to investigate possible LF systems that are capable of providing means to communicate with submerged submarines. Since ULF waves have a large skin depth in sea water, it seems natural to consider them for the stated purpose. A basis for the present work was formed in 1974 when TRW personnel performed preliminary calculations of generation of ULF signals by satellite-launched ion beams. The model used in the earlier calculations was a 'broad' ion beam. The term 'broad' means that finite beam radius effects were ignored. Thus, such an idealization, which is mathematically convenient, must lead to larger signals and higher efficiency than the realistic case of a beam of finite radial extent. Since the broad-beam calculation gave encouraging results, it was considered worthwhile to examine the finite-cross-section, or 'pencil' beam. The results of this analysis of a finite-radius beam of ions are presented.