Coherent Ion Acceleration Using Beating Electrostatic Waves

Abstract

118REPORT DOCUMENTATION PAGE R 05-The public reporting burden for this collection of information is estimated tol rage 1 hour per response, including the tim gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regar of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters S, (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that r subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control n PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY)2. REPORT TYPE 3. DATES COVERED (From -To) SPONSOR/MONITOR'S REPORT NUMBER(S)12. DISTRIBUTION/AVAILABILITY STATEMENT Distribution Statement A. Approved for public release; distribution is unlimited. SUPPLEMENTARY NOTES ABSTRACTThe results obtained from AFOSR-sponsored study on a new ion acceleration using beating electrostatic waves. Unlike previously known methods of energizing plasmas with electrostatic waves, and which accelerate only ions whose initial velocities are above a certain threshold (close to the waves velocity), the new mechanism can accelerate ions with arbitrarily small initial velocities. This results in significant improvements to the acceleration/heating efficiency (by as much as 45%) over previous techniques. The benefits to the state of the art of space propulsion stem from the high efficiency of the new mechanism,its thersholdless nature and its capabilities of producing high ion energies and its electrodeless character. In summary project accomplished the following: 1 Demonstrated theoretically that a new highly efficient ion acceleration mechanism by heating electrostatic (ES) waves is teal and ii a fundamental phenomenon that occurs only under specific conditions. 2. Studied using Monte Carlo simulations the effects of collisions (that would occur in a real low temperature plasma) on the ion acceleration mechanism and found that collisions can enhance the effects due to scattering of ions out of the forbidden region of phase space. 3. Designed and constructed a dedicated experiment to study the new ion acceleration mechanism. SUBJECT TERMS SECURITY CLASSIFICATION SYNOPSISIn this final technical report we document, in three chapters, the results obtained from our AFOSR-sponsored study on a new ion acceleration using beating electrostatic waves.Unlike previously known methods of energizing plasmas with electrostatic waves, and which accelerate only ions whose initial velocities are above a certain threshold (close to the waves velocity), the new mechanism can accelerate ions with arbitrarily small initial velocities (as illustrated in Fig. (1)). This results in significant improvements to the acceleration/heating efficiency (by as much as 45%) over previous techniques. The benefits to the state of the art of space propulsion stem from the high efficiency of the new mechanis...