Collisonal pumping for the production of intense spin-polarized neutral BEAMS: target considerations

Conference · Mon Jul 01 04:00:00 EDT 1985 · Fusion Technol.; (United States)

OSTI ID:5789301

Stearns, J W; Burrell, C F; Kaplan, S N; Pyle, R V; Ruby, L; Schlachter, A S

Neutral-beam heating and/or fueling offers the possibility of establishing deuteron and triton spins oriented parallel to the magnetic field (or antiparallel to the field). It is believed that the polarizations can be maintained by guide fields until the particles are within the reactor. A beam suitable for this magnetic fusion-energy application would require five to six orders of magnitude increase in polarized beam intensity from the limits imposed by present technology, which is on the order of 10-100 ..mu..A. We have recently proposed that ampere-sized beams of nuclear-spin-polarized ions and atoms can be produced by multiple atomic collisions in an electron-spin-polarized medium. By analogy to optical pumping, we have called the process ''collisional pumping.'' Such pumping will occur when an ion beam passes through a thick electron-spinpolarized target in a low magnetic field. As an ion in the beam undergoes a succession of electron-capture and -loss collisions, polarization is transferred from the electron to the nucleus through the hyperfine interaction. After a sufficient number of charge-changing collisions, both the electron and nuclear polarization of the beam will be pumped to the electron polarization of the target. We have analyzed and theoretically demonstrated several examples of collisional pumping; the case that lends itself to earliest testing is that of a low-energy (0.1 - 10 keV/u) hydrogen or deuterium beam passing through a thick electron-spin-polarized alkalivapor target in a low magnetic field.

• Research Organization: Lawrence Berkeley Laboratory, University of California, Berkeley, CA
• OSTI ID: 5789301
• Report Number(s): CONF-850310-
• Conference Information: Journal Name: Fusion Technol.; (United States) Journal Volume: 8:1
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700208* -- Fusion Power Plant Technology-- Inertial Confinement Technology
ANGULAR DISTRIBUTION
ATOM COLLISIONS
BEAM PRODUCTION
BEAMS
CHARGED PARTICLES
COLLISIONAL HEATING
COLLISIONS
DEUTERON BEAMS
DISTRIBUTION
HEATING
HIGH-FREQUENCY HEATING
HYDROGEN IONS
ION BEAM TARGETS
ION BEAMS
ION COLLISIONS
ION-ATOM COLLISIONS
IONS
MAGNETIC-PUMPING HEATING
ORIENTATION
PLASMA HEATING
POLARIZED BEAMS
SPIN ORIENTATION
TARGETS
TRITON BEAMS