Experimental measurement of emittance growth in mismatched space-charge-dominated beams

Conference · Sun Mar 01 04:00:00 EST 1987

OSTI ID:6506310

Tiefenback, M G

Using the Single Beam Transport Experiment (SBTE) at LBL, we have measured the emittance of a well-matched 4.6-mA beam of 122-keV Cs/sup +/ to be conserved from injection into through exit from an 80-lens segment of the AG focussing channel. We then mismatched the beam into the same channel such that the maximum (minimum) radius of the beam at the midplane between lenses was about 1.5 (0.5) times the former value. We caused mismatches in the envelope of the beam in both transverse dimensions (labeled a and b) in modes both symmetric (deltaa = deltab) and antisymmetric (deltaa = -deltab). We found the mismatch amplitude to decay during the beam transit through the channel for both modes of mismatch, although more so for the antisymmetric mode. We also found the emittance of the symmetrically mismatched beam to be the same as for the matched beam, while the emittance of the antisymmetrically mismatched beam grew by as much as a factor of four over that for the matched beam.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6506310
• Report Number(s): LBL-22275; CONF-870302-180; ON: DE87009446
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430200* -- Particle Accelerators-- Beam Dynamics
Field Calculations
& Ion Optics
BEAM EMITTANCE
BEAMS
ION BEAMS
MATHEMATICAL SPACE
PHASE SPACE
SPACE
SPACE CHARGE