Injection of electrons with predominantly perpendicular energy into an area of toroidal field ripple in a tokamak plasma to improve plasma confinement

Patent · Fri Jan 01 00:00:00 EST 1993

OSTI ID:868841

Ono, Masayuki ^[1]; Furth, Harold ^[2]

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1. Princeton Junction, NJ
2. Princeton, NJ

An electron injection scheme for controlling transport in a tokamak plasma. Electrons with predominantly perpendicular energy are injected into a ripple field region created by a group of localized poloidal field bending magnets. The trapped electrons then grad-B drift vertically toward the plasma interior until they are detrapped, charging the plasma negative. Calculations indicate that the highly perpendicular velocity electrons can remain stable against kinetic instabilities in the regime of interest for tokamak experiments. The penetration distance can be controlled by controlling the "ripple mirror ratio", the energy of the injected electrons, and their v.sub..perp. /v.sub.51 ratio. In this scheme, the poloidal torque due to the injected radial current is taken by the magnets and not by the plasma. Injection is accomplished by the flat cathode containing an ECH cavity to pump electrons to high v.sub..perp..

• Research Organization: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
• DOE Contract Number: AC02-76CH03073
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 5225146
• OSTI ID: 868841
• Country of Publication: United States
• Language: English

Related Subjects

injection
electrons
predominantly
perpendicular
energy
toroidal
field
ripple
tokamak
plasma
improve
confinement
electron
scheme
controlling
transport
injected
region
created
localized
poloidal
bending
magnets
trapped
grad-b
drift
vertically
interior
detrapped
charging
negative
calculations
indicate
highly
velocity
remain
stable
kinetic
instabilities
regime
experiments
penetration
distance
controlled
mirror
ratio
perp
51
torque
due
radial
current
accomplished
flat
cathode
containing
ech
cavity
pump
toroidal field
plasma confinement
field region
poloidal field
tokamak plasma
cathode containing
electron injection
field ripple
injection scheme
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