Beam properties of a high-perveance single-aperture dc extraction system

Journal Article · Sat Sep 01 04:00:00 EDT 1984 · Rev. Sci. Instrum.; (United States)

DOI:https://doi.org/10.1063/1.1137952· OSTI ID:6544190

Piosczyk, B; Dammertz, G

In continuous operation a positive hydrogen ion beam up to 240 mA has been extracted at 50 kV out of a single aperture, corresponding to a perveance of 2.1 x 10/sup -8/ A/V/sup 3//sup ///sup 2/. The effective mass of the extracted ion beam was measured to be about 1.8 amu. The current density distribution of the extracted ion beam was measured with a small calorimetric probe. It was found that the beam distribution strongly depends on the matching between the plasma current density and the extraction voltage. At overmatched conditions the ion beam may even become hollow. The distribution of the extracted ion beam depends on the pressure along the beam path. At pressures above 3 x 10/sup -4/ Torr H/sub 2/, the distribution was observed to be Gaussian. At a pressure 2 x 10/sup -5/ Torr H/sub 2/, the intensity in the wings of the beam is relatively high with respect to the intensity in the beam center. The beam divergence decreases with the square root of the extraction voltage. The space-charge potential of the neutralized beam is estimated to be about 5.6 V at 2 x 10/sup -5/ Torr decreasing to 1.6 V at 10/sup -3/ Torr independent of the beam energy.

• Research Organization: Kernforschungszentrum Karlsruhe GmbH, Postfach 3640, D-7500 Karlsruhe, Federal Republic of Germany
• OSTI ID: 6544190
• Journal Information: Rev. Sci. Instrum.; (United States), Journal Name: Rev. Sci. Instrum.; (United States) Vol. 55:9; ISSN RSINA
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430200* -- Particle Accelerators-- Beam Dynamics
Field Calculations
& Ion Optics
430302 -- Particle Accelerators-- Injection & Extraction Systems
ACCELERATORS
APERTURES
BEAM EXTRACTION
BEAM OPTICS
BEAMS
CALORIMETRY
CHARGED PARTICLES
DC SYSTEMS
DESIGN
DISTRIBUTION
ENERGY SYSTEMS
HYDROGEN IONS
ION BEAMS
IONS
OPENINGS
PHYSICAL PROPERTIES
POWER SYSTEMS
PRESSURE DEPENDENCE