Nonlinear longitudinal beam response measurements at the ALS
- Lawrence Berkeley National Lab., CA (US)
- Univ. of California, Berkeley, CA (US). Dept. of Physics
- Stanford Univ., CA (US). Stanford Linear Accelerator Center
The authors report on longitudinal beam-transfer function (BTF) measurements at the Advanced Light Source (ALS) for large phase-modulation amplitudes. As the amplitude of the swept-frequency excitation is increased, the dipole beam response around the synchrotron frequency develops a notch in the amplitude response with a corresponding sharp jump in the phase response. These observations are explained by a splitting of the beam into two beamlets created by the nonlinearity of the forced synchrotron oscillations. This is demonstrated with measurements of the longitudinal bunch profile using a streak camera. They also present measurements of the diffusion rate from one stable island to the other for a fixed modulation frequency and compare the measured rates with those expected from Touschek scattering. Finally, they comment on BTF measurements for sub- and superharmonic resonances.
- Research Organization:
- Stanford Univ., Stanford Linear Accelerator Center, CA (US); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Dept. of Physics, Berkeley, CA (US)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (US)
- DOE Contract Number:
- AC03-76SF00515; AC03-76SF00098; FG03-95ER40936
- OSTI ID:
- 666076
- Report Number(s):
- SLAC-PUB-7737; CONF-9710138-; ON: DE98059189; TRN: US200306%%116
- Resource Relation:
- Conference: Advanced IFCA workshop on beam dynamics issues for e+e- factories, Frascati (IT), 10/20/1997--10/25/1997; Other Information: Supercedes report DE98059189; PBD: Jan 1998; PBD: 1 Jan 1998
- Country of Publication:
- United States
- Language:
- English
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