MULTICASP SOURCE OF IONS WITH DOUBLE-STAGE ELECTRIC DISCHARGE Russian patent published in 2003 - IPC

FIELD: sources of charged particles utilized in acceleration equipment. SUBSTANCE: multicasp source of ions with double-stage electric discharge comprises cathode, intermediate electrode, anode with emission hole arranged in listed order and electrically insulated one from another. In addition intermediate electrode carries independent electromagnets which adjacent coils are connected in opposition and which magnetic cores come in the form of bars extended along longitudinal axis of ion source. Electromagnets form acute-angled multicasp magnetic field between cathode and anode which value nears zero on longitudinal axis of source and abruptly grows along radius in zone of bars. As result of structural changes there emerges new physical property: presence of magnetic field in entire gap between cathode and anode prevents drift of electrons of discharge to side surfaces which grows with removal from central longitudinal axis and plasma is activated in gap between intermediate electrode and anode by magnetic field which lines of force are perpendicular to direction of electric discharge field and value of this magnetic field has minimum lying on central longitudinal axis of source and grows abruptly on periphery. EFFECT: increased current and reduced spread of lateral velocities of ions in beam across outlet of ion source. 2 dwg