ANL, Argonne
YerPhI, Yerevan
A 5-wire vibrating wire monitor (VWM005) was developed and tested at the Advanced Photon Source (APS). The sensor was mounted on the outboard side of a bending-magnet synchrotron radiation terminating flange in sector 37 of the APS storage ring. The parallel wires were separated vertically by 0.5 mm; however, due to the possibility of rotation about a horizontal axis, the effective distance between the wires was reduced by 30%. To increase the response speed, the sensor was installed in air, resulting in a step response time of less than one second. Due to the extreme sensitivity of the detector, the very hard x-ray component of synchrotron radiation was successfully measured after its passage through the terminating flange.
BNL, Upton, Long Island, New York
In this paper we present algorithm of coupling correction in a storage ring based on monitoring the vertical size of a stored beam, while varying skew quadrupoles. The details of the algorithm realized as Matlab script and experimental results of its application are presented.
CERN, Geneva
The unprecedented intensity and energy of the LHC proton beams will require an excellent control of the transverse beam dynamics in order to limit particle loss in the superconducting systems. Due to restricted tolerances of the machine protection system and tight beam emittance blow-up budget only small beam excitation is allowed, making precise measurements of the transverse beam parameters very challenging. This paper describes the systems measuring the tune, coupling and chromaticity of the LHC beams. As manual correction of these parameters may reach its limit with respect to required precision and expected time-scales, the LHC is the first proton collider that can be safely and reliably operated only with automatic feedback systems for controlling the transverse beam dynamics. An outline of these systems is also presented.