POTENTIAL-WELL CONSERVED HELICITY INJECTED ELECTRON-BEAM-DRIVEN MILLIMETER WAVE SOURCE MODIFIED ORBITRON

THE OBJECTIVE OF THIS PROPOSAL IS TO DEVELOP A MORE EFFICIENT, HIGH POWER MILLIMETER WAVE SOURCE BY MODIFYING THE ORIGINAL ORBITRON MASER. THE ORIGINAL ORBITRON IS DRIVEN BY A SINGLE POWER SUPPLY (I.E.A SMALL CAPACITOR) WHICH GENERATES AN AXISYMMETRIC LOGARITHMIC POTENTIAL-WELL AS RADIALLY DIRECTING (AT FIRST) ELECTRON BEAMS IN THE TUBE OF COAXIAL GEOMETRY. HOWEVER, THE POSITIVE POTENTIAL (V(O)) INITIALLY APPLIED ON THE CENTER CONDUCTOR DECAYS CONTINUALLY AS THE DISCHARGE CURRENT INCREASES DUE TO THE INDUCTIVE LOAD OF THE ORBITRON TUBE, THEREBY PREMATURELY TERMINATING THE EMISSION OF HIGH FREQUENCY COMPONENTS (F(O)?SQ RT V(O)). SIMPLE REPLACEMENT OF THE CAPACITOR WITH A BATTERY IS NOT ECONOMICAL, BUT ALSO FLATTENS THE POTENTIALWELL AS THE DISCHARGE CURRENT INCREASES BEYOND THE TRANSITION FROM GLOW TO ARC. FOR SINGLY POWERED ORBITRONS, MORE THAN HALF THE RADIALLY INJECTED ELECTRONS IS LOST DIRECTLY TO THE ANODE, BEFORE PARTICIPATING IN THE MILLIMETERWAVE OSCILLATION BECAUSE OF THE LACK OF ACCELERATION BEFORE COLLISIONS. THE MAJOR EFFORT OF THIS PROPOSAL IS TO OVERCOME THE PROBLEM OF LOW EFFICIENCY THROUGH A MINIMUM MODIFICATION OF THE ORIGINAL ORBITRON MASER. TWO SEPARATE POWER SUPPLIES, ONE FOR THE POTENTIAL-WELL AND ANOTHER FOR THE ELECTRON BEAM, WILL BE EMPLOYED. A NOVEL SCHEME WOULD CONSERVE THE POTENTIAL-WELL UP TO VERY HIGH VOLTAGES, IMPORTANT FOR HIGH FRE-N QUENCY GENERAGION. THE ELECTRON BEAM WILL BE INJECTED EXTERNALLY BY MINIATURE GUNS IN THE TANGENTIAL DIRECTION SO THAT A MAJORITY OF ELECTRONS UNDERGOES A HELICAL ORBIT BEFORE REACHING THE CENTER CONDUCTOR (ANODE). OUR PRELIMINARY EXPERIMENT WITH A COLD-CATHODE ELECTRON GUN WAS ENCOURAGING. THE USEFULNESS OF A NUMBER OF SUCH GUNS AND THE EFFECT OF NON-ORTHOGONAL (WITH RESPECT TO THE TUBE AXIS) INJECTION WILL BE INVESTIGATED IN TERMS OF POWER AND EFFICIENCY ENHANCEMENT DURING THE PHASE I PERIOD. THE PROPOSED WORK WILL INCLUDE EXTENTION OF THEORY, PROOF-OF-THEORY EXPERIMENTATION ASSISTED BY NOVEL DIAGNOSTIC TECHNIQUES, AND FABRICATION AND CHARATERIZATION OF THE MODIFIED ORBITRON PROTOTYPE.