Quantitative shadowgraphy and proton radiography for large intensity modulations
Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics American Physical Society (2017)
Abstract:
Shadowgraphy is a technique widely used to diagnose objects or systems in various fields in physics and engineering. In shadowgraphy, an optical beam is deflected by the object and then the intensity modulation is captured on a screen placed some distance away. However, retrieving quantitative information from the shadowgrams themselves is a challenging task because of the non-linear nature of the process. Here, a novel method to retrieve quantitative information from shadowgrams, based on computational geometry, is presented for the first time. This process can also be applied to proton radiography for electric and magnetic field diagnosis in high-energy-density plasmas and has been benchmarked using a toroidal magnetic field as the object, among others. It is shown that the method can accurately retrieve quantitative parameters with error bars less than 10%, even when caustics are present. The method is also shown to be robust enough to process real experimental results with simple pre- and post-processing techniques. This adds a powerful new tool for research in various fields in engineering and physics for both techniques.AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment Elsevier 829 (2016) 76-82
Path to AWAKE: Evolution of the concept
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment Elsevier 829 (2016) 3-16
Intra-beam IP feedback studies for the 380 GeV CLIC beam delivery system
IPAC 2016 Joint Accelerator Conferences Website (2016)
Abstract:
In its currently-envisaged initial stage, the Compact Linear Collider (CLIC) will collide beams with a 380 GeV center of mass energy. To maintain the luminosity within a few percent of the design value, beam stability at the interaction point (IP) must be controlled at the sub-nanometer level. To help achieve such control, use of an intra-pulse IP feedback system is planned. With CLIC's very short bunch spacing of 0.5 ns, and nominal pulse duration of 176 ns, this feedback system presents a significant technical challenge. Furthermore, as part of a study to optimize the design of the beam delivery system (BDS), several L* configurations have been studied. In this paper, we will review the IP feedback simulations for the 380 GeV machine for two L* configurations, and compare luminosity recovery performance with that of the original L* configuration in the 3 TeV machine.Fast beam-collision feedbacks for luminosity optimisation at next-generation lepton colliders
Nuclear and Particle Physics Proceedings Elsevier 273 (2016) 188-192