Design and characterisation of frequency selective conductive materials for electromagnetic fields control.

To prevent the electromagnetic (EM) wakefields excitation, protect detectors from damage at a range of installations and facilities including particle accelerators the EM field control is required. Conductive foils or wires providing EM protection and required thermal and mechanical properties are normally used. We suggest novel composite materials with uniquely designed frequency selective conductivity enabling them to overcome the properties of the conventional materials, protect from EM fields and supress undesirable phenomena. Theoretical and experimental investigations are carried out and the conductivity of designed and composite (dual-layer) aluminium/graphene metamaterials as well as graphene and aluminium foils is studied. The EM properties of these materials are compared, and conditions of full and partial electromagnetic transparency are discussed. Results observed allow engineering materials capable of EM field control, instability suppression including those observed in high-intensity particle accelerators and enabling control of an EM field generating media including relativistic charge particle beams.

Beam impedance minimization for accelerator beamline insertion devices.

Use of complex state-of-the art detectors and monitors is essential to carry out high-energy and nuclear physics experiments at accelerator/collider facilities. The detectors are used to monitor charged particle beam parameters at large accelerator facilities such as coherent light sources and to develop new state-of-the art accelerators. Improvements in beam quality and lifetime necessitate the advancement of the instrumentation for successful operation of the accelerator facilities. Minimization of the beam-line-inserted devices' influence on the beam is therefore one of the essential considerations during the design of such facilities and the preparation of experiments. In this paper, we suggest and discuss a roadmap to minimize this influence. It is developed using fundamental concepts and numerical modeling, and we show that this is a multi-stage and multi-parametric problem that needs careful consideration. To illustrate the roadmap, the vacuum vessel for the vertex locator detector (CERN) is used. The results are discussed and, using them, the steps and stages of the design optimization are suggested. The suggested procedure can be applied to optimize the design of any beamline insertion device and will contribute to the development of next generation particle/accelerator detectors and monitors.