Beam funneling studies at Los Alamos

Conference · Fri Jan 01 04:00:00 EST 1988

DOI:https://doi.org/10.1016/0168-9002(89)91151-0· OSTI ID:6807906

Stovall, J E; Guy, F W; Stokes, R H; Wangler, T P

Funneling two ion beams by interlacing their bunches can reduce the cost and complexity of systems producing intense beams. Applications of funneling could include accelerators for heavy ion inertial fusion, electronuclear breeding, and fusion materials irradiation. Funneling in an RFQ-like structure is an elegant solution at low energy where electric fields are needed to provide strong focusing. Discrete-element funnels, with separate focusing elements, bending magnets, rebunchers and if deflectors, are more flexible. At sufficiently high energies, magnetic-quadrupole lenses can provide strong focusing in a discrete-element funnel. Such a funnel has been designed as a preliminary example of a second funnel in the HIBALL-II accelerator system. In a simulation, two Bi/sup +1/ (mass = 209 amu) beams at 0.5 MeV/A, 20 MHz, 40-mA, separated by 55 cm and angled at +-6/degree/ were combined into a single 80-mA beam at 40 MHz. Emittance growth was calculated, by a modified version of the PIC (particle-in-cell) code PARMILA, to be about 1%. Funnel design experience at Los Alamos has evolved rules-of-thumb that reduce emittance growth. Some of these are to maintain focusing periodicity and strength in both transverse and longitudinal directions; use strong focusing so that the bunch will be small; minimize angles of bend and rf deflection; adjust longitudinal focusing to produce a short bunch at the rf deflector; and design rf deflectors for a uniform electrical field. 4 refs., 3 figs., 2 tabs.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6807906
• Report Number(s): LA-UR-88-3277; CONF-8806101-2; ON: DE89000328
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430200* -- Particle Accelerators-- Beam Dynamics
Field Calculations
& Ion Optics
ACCELERATORS
BEAM BUNCHING
BEAM DYNAMICS
BEAM EMITTANCE
BEAM FOCUSING MAGNETS
BEAMS
DESIGN
ELECTRICAL EQUIPMENT
ELECTROMAGNETS
EQUIPMENT
ION BEAMS
LINEAR ACCELERATORS
MAGNETS
QUADRUPOLE LINACS
RF SYSTEMS