Energy loss to parasitic modes of accelerating cavities

Technical Report · Thu Jul 25 04:00:00 EDT 1974

OSTI ID:7167016

Sands, M

At the maximum stored current, each circulating beam in PEP will consist of three bunches, each about 10 cm long containing 1.5 /times/ 10/sup 12/ particles. The large electric charge carried by such a bunch (2.5 /times/ 10/sup /minus/7/ coulomb) will, because of its short length, give rise to a large transient excitation of hundreds of parasitic modes in the accelerating cavities. The energy loss of the stored beam to the cavities from this process may be comparable to the loss to synchrotron radiation, and may, therefore, require a significant increase in power from the accelerating rf system. In this note I considered three aspects of this effect. First, an attempt is made to estimate the magnitude of the energy loss of a bunch in a single passage through the accelerating cavities. Then, I consider the effects of the periodic passages of the bunches in a single stored beam. And finally, I look at the consequences of storing two counter-rotating beams. The general conclusions are that the magnitude energy loss to the parasitic modes is serious, though probably not disastrous; and that, in general, the separate stored bunches will act incoherently. 2 refs., 7 figs.

• Research Organization: Stanford Linear Accelerator Center, Menlo Park, CA (USA)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 7167016
• Report Number(s): SLAC-PEP-NOTE-90; ON: DE88013215
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430400* -- Particle Accelerators-- Storage Rings
BEAM BUNCHING
BEAM DYNAMICS
CAVITIES
ENERGY LOSSES
LOSSES
PEP STORAGE RINGS
RF SYSTEMS
STORAGE RINGS