Vibration diagnostics instrumentation for ILC

Abstract

The future ee + 500 GeV International Linear Collider will rely on unprecedented nanometer scale particle beam size at the interaction point, in order to achieve the design luminosity. Tight tolerances on static and dynamic alignment of the accelerator cavities and optical components are demanded to transport and focus the high energy electron and positron beams with reasonable position jitter and low emittance. A brief review of techniques and devices evaluated and developed so far for the vibration diagnostics of the machine is presented in this paper

Coil-free active stabilisation of extended payloads with optical inertial sensors

“…In fact, ground motion includes microseismic waves that have an amplitude of the order of 10 −6 m. Consequently, if ground motion is transmitted to a precision tool, it constitutes one of the most limiting factor to the resolution of the system [5]. Ground motion attenuation is particulary challenging for the stabilization of the electromagnets used to guide particle colliders beams.…”

“…However so far, to the best of the authors' knowledge, all of them are using electromagnetic sensors for inertial control at low frequency, which are not compatible with the environment of particle colliders [17]. Other sensitive seismic sensors exist but they also measure some parasitic signal due to the surrounding magnetic field and the particle beam; either the sensor flexure is build in a ferromagnetic material [5] or it includes elastomer or eletronics [18] which are damaged by the highenergy particle beam. New sensors based on an interferometric readout have been developed which can provide an accurate signal in this harsh environment [19][20][21].…”

“…Effective isolation from ground vibration is required for many applications including lithography machines [1], atomic force microscopy [2], atomic gravimetry [3], medical imaging, and large instruments dedicated to experimental physics [4]. In fact, ground motion includes microseismic waves that have an amplitude of the order of 10 −6 m. Consequently, if ground motion is transmitted to a precision tool, it constitutes one of the most limiting factors to the resolution of the system [5]. Ground motion attenuation is particulary challenging for the stabilization of the electromagnets used to guide particle colliders beams.…”