Transverse Diagnostics For High Energy Hadron Colliders

Abstract

The Large Hadron Collider (LHC) is a circular synchrotron accelerator that will explore new Physics at the higher energies ever achieved, aiming to find the Higgs boson. The LHC is being built at CERN and by 2007 it will be ready to produce head-on collisions of protons at a centre-of-mass energy of 14 TeV. The employment of superconducting magnets for achieving high energies, the high luminosity required for physics, the limited dynamic aperture and the large energy stored in the beams will make the machine very challenging to operate, especially during the injection process and the energy ramp. Two particular problems will be a high sensitivity to beam losses and a relatively poor field quality requiring the use of many types of magnetic correction elements. This may lead to the inclusion of certain beam measurements in feedback loops, making special demands on the control system. The injection and acceleration of the LHC proton beams without particle losses and emittance blow up will require an accurate control of the beam parameters. The value of the betatron tune is about 63 units and needs to be controlled to a level of $\Delta Q = ±0.003$. Orbit excursions should be limited to less than 0.5 mm. The linear chromaticity should be limited to some units (nominal value $Q'_HV = 2$). This Thesis will be focused on the improvement of new instrumentation for the measurement of beam parameters that is compatible with LHC high intens ity running. In this sense, the importance for the performance of the accelerator of terms such as tune or chromaticity will be pointed out. This work can be considered to be divided into two differentiated parts: the tests performed to a potentially beam diagnostics device and the improvement of the sensitivity of an already existing monitor. However, behind both subjects there is a common objective: the need of implementing new sensitive and non destructive methods for measuring parameters of major importance to keep the beam within the tight tolerances imposed to the superconducting and high energy accelerator LHC