Beam shape distortion caused by transverse wake fields
As a particle bunch in a storage ring 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 which results in various effects or instabilities in the motion of the bunch. In this paper the authors study one of these effects in which a transverse impedance causes the beam to be distorted in its shape. This distortion, observed at a fixed location in the storage ring, does not change from turn to turn; rather, it remains static in time. To describe the distortion, the bunch is considered to be divided longitudinally into many slices, and the centers of charge of the slices are connected 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 wake field, however, the curve becomes distorted; what the authors find in this paper is the shape of such a curve. The results obtained are applied to the PEP storage ring. The impedance is assumed to come solely from the RF cavities. The authors find that the beam shape is sufficiently distorted and hence that loss of luminosity due to this effect becomes a possibility.
- Research Organization:
- Stanford Linear Accelerator Ctr., Stanford Univ., Stanford, CA 94305
- OSTI ID:
- 5235808
- Report Number(s):
- CONF-830311-; TRN: 84-005754
- Journal Information:
- IEEE Trans. Nucl. Sci.; (United States), Vol. NS-30:4; Conference: Particle accelerator conference, Santa Fe, NM, USA, 21 Mar 1983
- Country of Publication:
- United States
- Language:
- English
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