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In order to further probe our understanding of the structure of matter and the universe, physicists constantly strive to create particle colliders that reach higher energies and luminosities. Improved technologies can partly help to fulfil these goals, however, novel experimental interaction region (EIR) optics and methods are also essential to this cause. This thesis covers several optics issues and solutions applicable to the Large Hadron Collider (LHC), its High Energy (HE-LHC) upgrade as well as the Future Circular Collider (FCC-hh). A key tool presented in this thesis is an optimisation method to produce short final focus triplets that produce large integrated gradients whilst having an aperture sufficiently large to sustain the beams and radiation shielding. The optimisation method uses a thin lens solution as a first approximation for the required quadrupole strength. This solution is outlined in the thesis, it has a large range of potential applications. This is demonstrated by using it to optimise the dynamic aperture of the Nuclotron-based Ion Collider fAcility (NICA), which is severely impacted by quadrupole fringe field effects. An optimised triplet for the FCC-hh is integrated into the EIR and the resulting optics as well as the general impact it has on the machine is presented in this thesis. It also presents how the LHC EIR can be modified for the HE-LHC, including the implementation of an optimised triplet. Dynamic aperture studies of the HE-LHC with triplet field errors were also performed in the scope of this work. Finally, a ballistic alignment optics for the LHC will be presented as well as a method that uses singular value decomposition to measure the offset of modulated quadrupoles. It will also be illustrated how this method can be used to improve the accuracy to optics measurements. These efforts can be used to improve the stability and luminosity of the LHC.

A Penning-type surface-plasma negative hydrogen (H-) ion source has been delivering beam at the ISIS pulsed spallation neutron and muon facility for over thirty years. It is one of the most powerful and well-renowned H- sources in the world. Although long-term experience has allowed the source to be operated reliably and set up in a repeatable way, it is treated as something of a 'black box': the detailed plasma physics of why it works has always been unclear. A vacuum Vessel for Extraction and Source Plasma Analyses (VESPA) has been developed to understand the ISIS ion source plasma and improve the beam extracted from it. The VESPA ion source is operated in a completely new regime whereby the analysing sector dipole magnet housed inside a refrigerated 'cold box', presently used on ISIS, is replaced by an on-axis extraction system. The new extraction system incorporates a novel einzel lens with an elliptical aperture. This is the first demonstration of an elliptical einzel being used to focus an asymmetric H- ion beam. With the dipole magnet removed, the ion source has been shown to produce 85 mA of H- beam current at normal settings; of which 80 mA is transported through the new einzel lens system, with a normalised RMS emittance of 0.2 π mm mrad. Optical emission spectroscopy measurements have shown a plasma density of 1019 m–3, an H2 dissociation rate of 70%, an almost constant electron temperature of 3.5 eV and an atomic temperature which linearly increases above the electron temperature. In support of these principal measurements, rigorous particle tracking, electrostatic and thermal simulations were performed. In addition, a suite of new equipment was manufactured by the author. This includes a fast pressure gauge, a temperature controller, a high voltage einzel lens circuit, a fast beam chopper and a caesium detection system.

Siemens Corporate Technology New Technology Fields Healthcare & Technology Concepts (CT NTF HTC) have proposed a novel electrostatic accelerator for nuclear medicine which aims at gradients of up to 10 MV m-1. With beam currents of 100 μA at ≈10 MeV it might replace cyclotrons whilst being simpler, more reliable and more cost effective. The accelerator concept consists of concentric hemispherical metallic shells spaced by insulators and placed in a vacuum system. The shells are interconnected by high voltage diodes so that they form a voltage multiplier with its highest voltage in its centre. Particle beams can be accelerated towards the centre through a set of holes in the shells. In tandem mode, with a stripper in the centre and a negative ion source as injector, beams of twice the centre voltage can be achieved. This thesis presents several commissioning milestones of a test system for the novel electrostatic accelerator, thus validating the concept for commercial applications. An inter shell insulator has been designed and successfully tested to fields of 12 MV m-1. A diode protection concept has been devised and validated in realistic breakdown scenarios. An AC drive system including control software has been developed, delivering a sinusoidal input voltage of up to 140 kV peak to peak at 80 kHz. An automatic process to carefully commission the high voltage system in vacuum has been created, implemented in a control system and successfully operated. A 4-shell prototype with these components has been successfully tested with achieved gradients of up to 5.5 MV m-1. A negative hydrogen ion source has been constructed, commissioned and characterised with a purposely developed wire grid. Beam currents beyond 200 μA have been achieved. Beam transport from the ion source through the 7-shell system has been demonstrated in simulations which are based on experimental data from the ion source characterisation. A stripper system has been designed and constructed.