Electrical diagnostics of the magnetically confined anode plasma source

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:428029

Crawford, M T; Johnson, D J; Maenchen, J E ^[1]

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1. Sandia National Labs., Albuquerque, NM (United States)

The Magnetically confined Anode Plasma (MAP) ion diode is designed to provide intense, repetitive, high-purity ion beams for materials processing. These ion beams are used for surface treatments of metals and polymers. The MAP diode can provide tens of kiloamps of ion beam current at > 500 kV acceleration potentials. Previous models have been operated at up to 100 Hz in a burst mode. The source of the ions is a magnetically confined plasma which is generated by ionizing a puff of neutral gas. The ionization of the gas is performed by induced electric fields from a fast rising ({approximately}2 {micro}s) magnetic field pulse. This magnetic field is also used to move the plasma into proper position for extraction by the accelerator voltage pulse. Plasma diagnostics have been performed primarily with bare-wire B-dot probes, Langmuir probes and time-integrated and time-resolved photography. Neutral gas measurements were made with very sensitive piezo-resistive (PZR) pressure transducers and fast ionization gauge (FIG) tubes. Differential B-dot pair arrays were employed to determine the magnetic fields generated by the fast coil and to note the change in those magnetic fields due to the plasma formation and motion. Langmuir probe data, used in conjunction with the B-dots to determine arrival times of the plasma, is presented as well.

• OSTI ID: 428029
• Report Number(s): CONF-960634--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ION SOURCES
METALS
PLASMA DIAGNOSTICS
PLASMA DRIFT
PLASMA PRODUCTION
POLYMERS
SURFACE TREATMENTS
THERMIONIC DIODES