Orbit distortion and beam tilt caused by transverse wake fields

Technical Report · Tue Sep 01 04:00:00 EDT 1981

DOI:https://doi.org/10.2172/6788802· OSTI ID:6788802

Chao, A W; Kheifets, S

As particle bunch passes through a region with a transverse impedance, it generates a transverse wake electromagnetic field that is proportional to the transverse displacement of the bunch in the region. The field acts back on the bunch, causing various effects (such as instabilities) in the motion of the bunch. In this note, we study one of such effects in which a transverse impedance causes the beam to be distorted in its shape. Observed at a fixed location in the storage ring, this distortion does not change from turn to turn; rather, the distortion is static in time. To describe the distortion, let us cut the bunch longitudinally into many slices and connect the centers of charge of the slices into a curve. In the absence of transverse impedance, this curve is a straight line parallel to the direction of motion of the bunch. Perturbed by the transverse EM field, the curve becomes distorted. What we will find in this note is the shape of such a curve. We emphasize the fact that the effect we are considering is a static effect. The beam is assumed to be stable in this statically distorted state. The distortion is a result of having the bunch passing by the impedance off-centered; the produced wake then acts on the particles, causing them to follow distorted closed orbits which depend on the longitudinal positions of the particles. 10 refs., 1 fig.

• Research Organization: Stanford Linear Accelerator Center, Menlo Park, CA (USA)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 6788802
• Report Number(s): SLAC-PEP-NOTE-365; ON: DE89006360
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430200 -- Particle Accelerators-- Beam Dynamics
Field Calculations
& Ion Optics
430400* -- Particle Accelerators-- Storage Rings
BEAM BUNCHING
BEAM CURRENTS
BEAM DYNAMICS
BEAM EMITTANCE
CURRENTS
DIFFERENTIAL EQUATIONS
ELECTRIC IMPEDANCE
EQUATIONS
EQUATIONS OF MOTION
IMPEDANCE
INSTABILITY
ORBITS
PARTIAL DIFFERENTIAL EQUATIONS
PEP STORAGE RINGS
STORAGE RINGS