Search

Future large-scale particle accelerators, for example, the Future Circular Collider (FCC), the Compact Linear Collider (CLIC) and the International Linear Collider (ILC), will require significant RF drive power on the order of 100 MW. Thus, an RF source with high efficiency is preferable to minimise the overall power required. Klystrons represent an attractive RF source, with the current state of the art operating at efficiencies of up to 70%. Such devices feature monotonic bunching, where at the output cavity, a number of electrons will not be in the main bunch, and instead will be present in the anti-bunch, and therefore not contributing to the output power. Therefore, novel bunching methods, such as the Core Oscillation Method (COM), are worthy of investigation. By allowing the core of the electron beam to bunch and de-bunch between successive cavities, the number of electrons contained in the final bunch can increase, and therefore improve the efficiency of the device. Numerical simulation of klystrons featuring COM will be presented, with efficiencies of up to 85% being predicted thus far.

The next generation of particle accelerators will require the training of greater numbers of specialist accelerator physicists and engineers . These physicists and engineers should have a broad understanding of accelerator physics as well as the technology used in particle accelerators as well as a specialist in some area of accelerator science and technology . Such specialists can be trained by combining a University based PhD, in collaboration with national laboratory training with a broad taught accelerator lecture program. In order to have a faster start we decided to run an intensive two week school to replace the basic course at the Cockcroft Institute. At the same time we decided to investigate the use of problem based learning to simulate the way accelerator science tends to work in practice. In this exercise he students worked in groups of 5 to design a 3rd generation light source from scratch based on photon light specifications. In comparison to similar design exercises we stipulate that all students must do all parts and students are not allowed to specialise. A comparison with a standard lecture based education programme is discussed in this paper.

The Fermilab Muon g-2 Experiment (E989) contains flat-plate electrostatic quadrupoles, curved with the reference trajectory as defined by the constant, uniform magnetic dipole field. To understand the beam behaviour at a sufficient level, we require fast, high-accuracy particle tracking methods for this layout. Standard multipole fits to numerically calculated 2D transverse electric field maps have provided a first approximation to the electric field within the main part of the quadrupole, but cannot model the longitudinal curvature or extended fringe fields of the electrostatic plates. Expressions for curvilinear multipoles can be fit to a 2D transverse slice taken from the central point of a numerically calculated 3D electric field map of the quadrupole, providing a curved-multipole description. Generalised gradients can be used to model the fringe field regions. We present the results of curvilinear multipole and generalised gradient fits to the curved quadrupole fields, and the differences in tracking using these fields over 200 turns of a model of the storage ring in BMAD.

The new muon g-2 experiment at Fermilab (E989) aims to measure the anomalous magnetic moment of the muon to an uncertainty of 140 ppb. The existing accelerator facility at Fermilab is being adapted to the requirements of the g-2 experiment and the baseline lattice design is now established. This paper presents the results of beam simulations and spin tracking carried out using the Bmad software package for the g-2 beam transport system, including a variant which bypasses the delivery ring as proposed for the beam commissioning.

Terahertz(THz)-driven dielectric-lined waveguides have applications in electron manipulation, particularly acceleration, as the use of dielectric allows for phase velocities below the speed of light. However matching a single frequency to the correct velocity does not maximise electron-THz interaction; waveguide dispersion typically results in an unmatched group velocity and so the pulse envelope of a short THz pulse changes along the length of the structure. This reduces field amplitude and therefore accelerating gradient as the envelope propagates at a different velocity to the electron. Presented here is an analysis of the effect of waveguide dispersion on THz-electron interaction and its influence on structure dimensions and choice of THz pulse generation. This effect on net acceleration is demonstrated via an example of a structure excited by a single-cycle THz pulse, with a comparison of multi-cycle, lower intensity THz pulses on net acceleration.