Positive ion source

Claim 1

AN ION SOURCE COMPRISING A PLURALITY OF SPACED AND AXIALLY ALIGNED, AND CENTRALLY APERTURED CONDUCTIVE PLATES, A PLURALITY OF AXIALY ALIGNED, HOLLOW, CYLINDRICAL, ELECTRICAL INSULATING MEMBERS DISPOSED IN ALTERNATING RELATION WITH AND BUTTING SAID PLATES THEREBY DEFINING A HOLLOW, CYLINDRICAL REGION, MEANS FOR MAINTAINING AN AIR-TIGHT SEAL BETWEEN SAID PLATES AND SAID CYLINDRICAL MEMBERS, A FIRST OF SAID PLATES SUPPORTING A HEATABLE FILAMENT IN SAID REGION FOR PRODUCING ELECTRONS THEREIN, A SECOND OF SAID PLATES SUPPORTING A CONICAL ELECTRODE HAVING ITS APEX AXIALLY APERTURED AND DIRECTED AWAY FROM SAID FILAMENT, A THIRD OF SAID PLATES SUPPORTING AN AXIALLY APERTURED ANODE ADJACENT THE APEX OF SAID CONICAL ELECTRODE, SAID SECOND AND THIRD PLATES BEING PARAMAGNETIC, A MAGNETIC STRUCTURE REMOVABLY SUPPORTED EXTERNALLY OF SAID REGION AND SECURED TO AT LEAST ON OF SID PARAMAGNETIC PLATES, SAID MAGNETIC STRUCTURE PROVIDING A MAGNETIC CIRCUIT BETWEEN SAID SECOND AND THIRD PLATES, MEANS FOR ESTABLISHING A MAGNETIC FLUX IN SAID MAGNETIC CIRCUIT, AND MEANS FOR ADMITTING A NEUTRAL GAS INTO THE REGION BETWEEN SAID ANODE OF SAID FILAMENT.