Proton ring trapping in a magnetic mirror

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5403278

Pedrow, P D

A rotating beam of 430 keV protons was trapped in a 1.5 m long magnetic mirror using a fast gated coil and was studied for up to 4 ..mu..s. The protons were detected using magnetic probes, Faraday cups, and heat-sensitive witness targets. The ring was injected through a magnetic cusp where about 90% of its total energy was converted to rotational energy resulting in an axial velocity of about 3 m/..mu..s. The inside and outside diameters of the ring were typically 10 cm and 28 cm, respectively. The rings were propagated in puffed and static hydrogen with pressures as high as 300 mtorr for the purpose of space-charge neutralization. Eight passes through the length of the mirror were observed before the rings became undetectable. The measured proton inventory in the ring was typically 2 x 10/sup 15/ protons on the first pass and 2 x 10/sup 13/ on the eighth and final pass. Particle losses are attributed to charge-exchange and transmission of particles through the end mirrors. Mirror losses due to: (1) particles emerging from the cusp with too much residual parallel energy, (2) the upstream mirror being weaker than the downstream mirror, and (3) the pitch-angle of some particles might have changed during propagation, possibly due to asymmetric space-charge regions or instabilities.

• Research Organization: Cornell Univ., Ithaca, NY (USA)
• OSTI ID: 5403278
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
MAGNETIC MIRRORS
TRAPPED PROTONS
DETECTION
PARTICLE LOSSES
BEAM NEUTRALIZATION
CHARGE EXCHANGE
RINGS
SPACE CHARGE
BARYONS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
NUCLEONS
OPEN PLASMA DEVICES
PROTONS
THERMONUCLEAR DEVICES
700101* - Fusion Energy- Plasma Research- Confinement
Heating
& Production