Status of the CLIC-UK R&D programme on design of key systems for the compact linear collider
IPAC 2014: Proceedings of the 5th International Particle Accelerator Conference (2014) 1354-1357
Abstract:
Six UK institutes are engaged in a collaborative R&D programme with CERN aimed at demonstrating key aspects of technology feasibility for the Compact Linear Collider (CLIC). We give an overview and status of: 1) Drive-beam components: quadrupole magnets and the beam phase feed-forward prototype. 2) Beam instrumentation: stripline and cavity beam position monitors, an electro-optical longitudinal bunch profile monitor, and laserwire and diffraction and transition radiation monitors for transverse beam-size determination. 3) Beam delivery system and machinedetector interface design, including beam feedback/control systems and crab cavity design and control. 4) RF structure design. In each case we report on the status of prototype systems and performance tests with beam at the CTF3, ATF2 and CESRTA test facilities, including plans for future experiments.Experimental validation of a novel compact focusing scheme for future energy-frontier linear lepton colliders.
Physical review letters 112:3 (2014) 034802
Abstract:
A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed in 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This scheme has many advantageous properties over previously studied focusing schemes, including being significantly shorter for a given energy and having a significantly better energy bandwidth. Experimental results from the ATF2 accelerator at KEK are presented that validate the operating principle of such a scheme by demonstrating the demagnification of a 1.3 GeV electron beam down to below 65 nm in height using an energy-scaled version of the compact focusing optics designed for the ILC collider.Cavity beam position monitor at the interaction point region of accelerator test facility 2
IPAC 2013: Proceedings of the 4th International Particle Accelerator Conference (2013) 807-809
Abstract:
Nanometre resolution cavity beam position monitors (BPMs) have been developed to measure the beam position and to be linked to control the beam position stability within a few nanometres in the vertical direction at the focus, or Interaction Point (IP), of the Accelerator Test Facility 2 (ATF2). In addition, for feedback applications a lower-Q and hence faster decay time system is desirable. Two cavity so-called IP BPMs have been installed inside the IP chamber at the ATF2 focus area. To measure the resolution of IPBPMs two additional C-band cavity BPMs have been installed one upstream and one downstream of the IP. One cavity BPM has been installed at an upstream vertical image point of the IP. The performance of the BPMs is discussed and the correlation between the IP and image point positions is presented along with a discussion of using these BPMs for position stabilisation at the IP. Copyright © 2013 by JACoW.Development of a high-resolution, broad-band, stripline beam position monitoring system
IPAC 2013: Proceedings of the 4th International Particle Accelerator Conference (2013) 804-806
Abstract:
A low-latency, sub-micron resolution stripline beam position monitoring system has been developed and tested with beam at the KEK Accelerator Test Facility, where it has been used as part of a feedback system for beam stabilisation. The fast analogue front-end signal processor is based on a single-stage down-mixer and is combined with an FPGA-based system for digitisation and feedback control. A resolution as low as 400 nm has been demonstrated for beam intensities of ∼1 nC, with singlepass beam. The latest results of recent modifications to balance the input path lengths to the processor will be discussed. These modifications compensate for the inherent phase sensitivity of the processors, and hence improve the intrinsic resolution, without the need for offline correction. Modifications to the FPGA firmware will also be described, to allow for flexible operation with variable system-synchronous data acquisition at up to 400 MHz, with up to nine data channels of 13-bit width, and a nominal record length of 1 kS/channel/pulse (extensible to a total record length of 120 kS per pulse, for example, for use with long bunch trains or wide-band multi-turn measurements in storage rings). Copyright © 2013 by JACoW.Latest performance results from the font 5 intra train beam position feedback system at ATF
IPAC 2013: Proceedings of the 4th International Particle Accelerator Conference (2013) 3049-3051