The ion beam opening switch

Journal Article · Tue Dec 01 04:00:00 EST 1987 · IEEE Trans. Plasma Sci.; (United States)

DOI:https://doi.org/10.1109/TPS.1987.4316785· OSTI ID:5370082

Greenly, J B; Rondeau, G D; Sheldon, H T; Dreike, P L

Plasma opening switches (POS's) have shown excellent characteristics in pulsed power applications. Proposed POS scaling predicts that the fastest opening time for a given conducted current should occur using a high-velocity low-density plasma as the switch medium. The ion beam opening switch (IBOS) uses a charge-neutral ion beam of 100-300 kV, less than or equal to 120 A/cm/sup 2/ as the switch ''plasma''. Its velocity of up to 600 cm/..mu..s and density of -- 10/sup 12//cm/sup 3/ make this a very fast low-density plasma compared with typical 10 cm/..mu..s and 10/sup 13//cm/sup 3/ POS plasmas. The IBOS has conducted greater than or equal to 70 kA flowing in a parallel-plate transmission line driven by a 4-..cap omega.. pulser. IBOS opening time is load dependent, being less than or equal to4 ns into a 15-nH load and about twice as long into a 4-..cap omega.. electron diode load. However, switch impedance is not zero during the entire conduction time, rising to greater than or equal to 3 ..cap omega.. by the time of peak current. Peak current conducted before opening does not vary linearly with either injected ion current or switch axial length. Instead, the conduction current scales with plasma density in the switch, and is nearly independent of switch area until the area is restricted to a narrow (-- 1 cm) strip. In this experimental geometry, replacing the IBOS with a standard POS gave essentially identical behavior, except first, an order of magnitude less injected flux was required to conduct a given current with the POS than with IBOS, corresponding to similar injected plasma densities for the two types of switches; second, clear evidence of J X B motion of the POS plasma was seen, while none was evident with IBOS.

• Research Organization: Lab. of Plasma Studies, Cornell Univ., Ithaca, NY 14850 (US)
• OSTI ID: 5370082
• Journal Information: IEEE Trans. Plasma Sci.; (United States), Journal Name: IEEE Trans. Plasma Sci.; (United States) Vol. PS-15:6; ISSN ITPSB
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700209* -- Fusion Power Plant Technology-- Component Development & Materials Testing
BEAMS
CURRENTS
ELECTRIC CURRENTS
ELECTRICAL EQUIPMENT
ELECTRONIC EQUIPMENT
ENERGY SYSTEMS
EQUIPMENT
FUNCTION GENERATORS
ION BEAMS
OPERATION
PLASMA DENSITY
PLASMA SWITCHES
POWER SYSTEMS
PULSE GENERATORS
SWITCHES