A prototype energy spectrometer for the ILC at end station a in SLAC
The main physics program of the International Linear Collider requires a measurement of the beam energy with a relative precision of the order 10-4 or better. A magnetic spectrometer using high resolution beam position monitors (BPMs) has been proposed to achieve this goal. A prototype spectrometer chicane employing four dipole magnets is currently under development at the End Station A in SLAC, intending to demonstrate the required resolution and stability of this method and investigate possible systematic effects and operational issues. This contribution reports on the successful commissioning of the beam position monitor system and the resolution and stability achieved. Also, the initial results from a run with a full spectrometer chicane are presented.
CAVITY BPM DESIGNS, RELATED ELECTRONICS AND MEASURED PERFORMANCES
Future accelerators like the International Linear Collider and Free-Electron Lasers require beam position measurements with submicron resolution in critical parts of the ma-chines. This is achievable using the Cavity Beam Position Monitors (BPM). This paper presents the basic principles of this monitor type. Different institutes are working on the design of cavity BPM systems. An overview of recent developments with results and limitations is given.
Detection of beam induced dipole-mode signals in the SLC S-band structures
Beam emittance dilution caused by wakefield effects is one of the important issues in the SLC linac. The detection of beam induced dipole mode signals in the C-band range could provide a direct measure of the strength of transverse wakefield kicks the beam experiences in the accelerating structures. We investigate the applicability of these microwave signals for beam steering purposes. The RF distribution system in the linac sectors 2, 6 and 29 has been equipped with a simple experimental setup to observe the beam induced dipole mode signals. The paper discusses the setup, the mode-structure of the observed signals as well as experimental results from beam steering scans, obtained during the 95/96 SLC runs.