Design desiderata for a laminar flow quadrupole-focused acceleration column

Conference · Sat Jan 01 04:00:00 EST 1983

OSTI ID:5331691

Maschke, A W

The Pierce design acceleration column has been widely used to accelerate high current beams. It operates well in the space charge limited condition, and will produce beams with a temperature comparable with that of the source. It is restricted in current density, however, by the Child-Langmuir relation. If the ion source itself is not the limiting constraint, then the achievable current density is limited by the electric field at which sparking occurs. One sees clearly that the achievable current density decreases as one goes to higher voltages. This can be easily overcome by using electrostatic quadrupole focusing in the acceleration column. Now it can be shown that the space charge limited current density in a constant energy quadrupole transport channel is greater than that if one assumes that the electric fields on the quadrupoles can be as high in the ion source extraction electric fields. In practice, this is a conservative assumption. It follows that if the beam can be transported a large distance at the C-L current density limit, it can surely be accelerated as it goes from quadrupole to quadrupole. Hence, the necessity of having a high gradient acceleration column goes away.

• Research Organization: Brookhaven National Lab., Upton, NY (USA)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5331691
• Report Number(s): BNL-34186; CONF-831180-19; ON: DE84006534
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430200* -- Particle Accelerators-- Beam Dynamics
Field Calculations
& Ion Optics
ACCELERATORS
BEAM TRANSPORT
BEAMS
BREAKDOWN
CURRENT DENSITY
ELECTROSTATIC ACCELERATORS
ELECTROSTATIC LENSES
ION BEAMS
LENSES
MULTIPOLES
QUADRUPOLES
SPACE CHARGE