Apparatus for the mass analysis of plasmas on a continuous basis

Claim 1

A VELOCITY SELECTOR MASS ANALYZER FOR CONTINUOUSLY ANALYZING THE IONIC COMPOSITION OF A PLASMA SOURCE, COMPRISING A SOURCE OF PLASMA TO BE ANALYZED, A SMALL, CYLINDRICAL OUTER TUBE, A TAPERED NOSE CONE MOUNTED IN ONE END OF SAID TUBE, SAID CONE BEING PROVIDED WITH A NARROW, ION ENTRANCE SLIT IN THE APEX THEREOF, SAID SLIT BEING CLOSELY SPACED FROM SAID PLASMA SOURCE, CLOSURE MEANS MOUNTED IN THE OTHER END OF SAID TUBEM A FIRST PAIR OF CLOSELY SPACED, PARALLEL PLATE ELECTRODES INSULATED FROM AND MOUNTED WITHIN SAID TUBE, SAID FIRST PAIR OF ELECTRODES BEING AXIALLY ALIGNED WITH THE AXIS OF SAID TUBE AND WIHT SAID ENTRANCE SLIT OF SAID NOSE CONE AND BEING CLOSELY SPACED FROM SAID SLIT, A SECOND PAIR OF PARALLEL PLATE ELECTRODES INSULTATED FROM AND MOUNTED WITHIN SAID TUBE AND BEING PARALLEL TO AND IN ALIGNMENT WITH SAID FIRST PAIR OF ELECTRODES, A SOURCE OF D.C. ACCELERATING POTENTIAL HAVING A POSITIVE TERMINAL AND A NEGATIVE TERMINAL, MEANS FOR CONNECTING SAID POSITIVE TERMINAL TO GROUND AND TO SAID NOSE CONE, MEANS FOR CONNECTING SAID NEGATIVE TERMINAL TO ONE OF SAID FIRST PAIR OF ELECTRODES AND TO ONE OF SAID SECOND PAIR OF ELECTRODES, A SOURCE OF A.C. POTENTIAL, MEANS FOR CONNECTING SAID A.C. SOURCE ACROSS SAID FIRST PAIR OF ELECTRODES, MEANS FOR PROVIDING A MAGNETIC FIELD, SAID FIELD HAVING A DIRECTION PARALLEL TO SAID ELECTRODES, THE SPACING BETWEEN SAID FIRST PAIR OF ELECTRODES SERVING AS A VELOCITY SELECTING REGION FOR IONS DRAWN THEREBETWEEN THROUGH SAID NOSE CONE ENTRANCE SLIT BY SAID ACCELERATING POTENTIAL FROM SAID SOURCE OF PLASMA UNDER ANALYSIS, SAID SPACING BETWEEN SAID FIRST PAIR OF ELECTRODES BEING PROVIDED WITH AN ELECTROSTATIC FIELD BY THE POTENTIALS APPLIED THEREACROSS, THE FORCE ON AN ION DUE TO SAID ELECTROSTATIC FIELD BEING MADE EQUAL AND OPPOSITE TO THE FORCE ON THE SAME ION DUE TO SAID MAGNETIC FIELD TO PREVENT THE IONS IN SAID VELOCITY SELECTING REGION FROM STRIKING EITHER OF SAID FIRST PAIR OF ELECTRODES AS SAID IONS PASS THROUGH SAID REGION, THE OTHER ELECTRODE OF SAID SECOND PAIR OF ELECTRODES SERVING AS A COLLECTOR PLATE FOR THE IONIC SPECIES SEPARATED IN SAID VELOCITY SELECTED REGION BY VARIATIONS IN SAID A.C. POTENTIAL ACROSS SAID FIRST PAIR OF ELECTRODES, A DUEL BEAM OSCILLOSCOPE, MEANS FOR CONNECTING SAID COLLECTOR ELECTRODE AND SAID D.C. NEGATIVE TERMINAL AND ONE TERMINAL OF SAID A.C.