Design of a neutrino source based on beta beams

"Beta Beams" produce collimated pure electron (anti-) neutrino beams by accelerating beta active ions to high energies and having them decay in a race track shaped storage ring of 7 km circumference, the Decay Ring. EUROnu Beta Beams are based on CERN infrastructures and existing machines. Using existing machines may be an advantage for the cost evaluation, however, this choice is also constraining the Beta Beams. The isotope pair of choice for the Beta Beam is 6He and 18Ne. However before the EUROnu studies one of the needed isotopes, 18Ne, could not be produced in rates that satisfy the needs for physics reach of the Beta Beam. Therefore, studies of alternative beta emitters, 8Li and 8B, with properties interesting for a Beta Beam have been proposed and have been studied within EUROnu. These alternative isotopes could be produced by using a small storage ring, in which the beam traverses a target, creating the 8Li and 8B isotopes. This Production Ring, the injection Linac and the target system have been evaluated. Measurements of the cross-section of the reactions to produce the Beta Beam isotopes show interesting results. A device to collect the produced isotopes from the target has been developed and tested. However, the obtained rates of the 8Li and 8B, using the Production Ring for production of 8Li and 8B, is not yet, according to simulations, giving the rates of isotopes that would be needed. Therefore, a new method of producing the 18Ne isotope has been developed and tested giving good production rates. The baseline presented for the Beta Beam is therefore now to use the 6He and 18Ne isotopes for neutrino production. A 60 GHz ECRIS prototype, the first in the world, was developed and tested with contributions from EUROnu. The Beta Beam has to take into account the modifications of the injectors planned in view of LHC-upgrades. The Decay Ring lattices for the 8Li and 8B have been developed, the lattice for 6He and 18Ne has been optimized also to ensure the high intensity ion beam stability

At scale, experimental capture of electrical response of carbon fibre composites to inform integrated electrical power and structural systems

The electrification of aircraft systems and the light weighting of aero-structures using carbon fibre reinforced polymers (CFRP) are two key enabling technologies supporting the decarbonisation of flight. Close physical integration of the electrical and structural systems offers an opportunity to optimise the combined system weight and volume, and optimise system performance. In such integrated structural systems, electrical current may flow through the CFRP under faulted conditions to reach the current return network. A major barrier to their design is the poorly understood low frequency (CFRP. This paper presents the extrapolation of the response of CFRP to higher currents, including investigation of power dissipation levels and the time taken to reach key threshold temperatures linked to the thermal degradation of CFRP. These results inform design criteria for integrated systems and dual use materials to enable the adaption of CFRP to handle return currents

Dynamic performance of a low voltage microgrid with droop controlled distributed generation

Microgrids are small-scale highly controlled networks designed to supply electrical energy. From the operational point of view, microgrids are active distribution networks, facilitating the integration of distributed generation units. Major technical issues in this concept include system stability and protection coordination which are significantly influenced by the high penetration of inverter-interfaced distributed energy sources. These units often adopt the frequency-active power and voltage-reactive power droop control strategy to participate in the load sharing of an islanded microgrid. The scope of the paper is to investigate the dynamic performance of a low voltage laboratory-scale microgrid system, using experimental results and introduce the concept of Prony analysis for understanding the connected components. Several small disturbance test cases are conducted and the investigations focus on the influence of the droop controlled distributed generation sources

Voltage based current compensation converter control for power electronic interfaced distribution networks in future aircraft

Superconductors have a potential application in future turboelectric distributed propulsion (TeDP) aircraft and present significant new challenges for protection system design. Electrical faults and cooling system failures can lead to temperature rises within a superconducting distribution network, which necessitates a reduction or temporary curtailment of current to loads to prevent thermal runaway occurring within the cables. This scenario is undesirable in TeDP aircraft applications where the loads may be flight-critical propulsion motors. This article proposes a power management and control method that exploits the fast-acting measurement and response capabilities of the power electronic interfaces within the distribution network to maximize current supply to critical loads, reducing the impact of a temperature rise event in the superconducting distribution network. This new algorithm uses the detection of a resistive voltage in combination with a model-based controller that estimates the operating temperature of the affected superconducting cable to adapt the output current limit of the associated power electronic converter. To demonstrate the effectiveness of this method and its impact on wider system stability, the algorithm is applied to a simulated voltage-source converter supplied aircraft dc superconducting distribution network with representative propulsion motor loads

Low frequency design criteria for carbon fibre composite casings for aircraft power electronic converters

Two key technologies supporting decarbonisation of aviation are the light-weighting of aircraft structures, and the electrification of on-board power and propulsion systems. Achieving the target high power densities required for electrical power system equipment, including power electronic converters (PEC) is extremely challenging. A modularised electrical power system (EPS) which exploits the use of carbon fibre reinforced polymer (CFRP), rather than aluminium, for non-electrically active components (e.g., casings) for EPS equipment offers an opportunity for more compact, lightweight equipment design. However, existing knowledge of the electrical response of CFRP at a component scale, and how this impacts on the design of systems where electrical and structural systems interact, is limited. This paper provides a set of low frequency (<200 kHz), component scale models of a quasi-isotropic layup of CFRP, suitable for use with a behavioural simulation model of a 6-switch inverter to investigate the influence of casing on fault response, and enable capture of design criteria for resilient, low frequency design of CFRP casings for PECs. This includes investigation of key design interdependencies including influence of CFRP layup, design of electrical bonding points and interdependencies with wider system design considerations, including protection strategies

First-fault detection in DC distribution with IT grounding based on Sliding Discrete Fourier-Transform

Since dc distribution minimizes the number of power conversion stages, it lowers the overall cost, power losses, and weight of a power system. Critical systems use IT grounding because it is tolerant to the first-fault. Hence, this is an attractive option for hybrid electric aircraft (HEA), which combines gas engines with electric motors driven by power electronic converters. This letter proposes an accurate implementation for the procedure of first-fault detection with IT grounding. The ac component injection along with the sliding discrete Fourier transform (SDFT) is used to estimate the fault impedance. The procedure is very accurate due to the heavy filtering of the implicit moving average filter. Further computation savings are obtained by using the double look-up tables, and the Goertzel algorithm for the SDFT. Results are validated by simulations and experiments

Electrical protection solutions enabling integrated electrical power and composite structure systems for aircraft

The combined dual trends for increased use of electrical power for more-electric aircraft (MEA) and carbon fibre reinforced polymer (CFRP) for light weight aircraft structures have been pursued to improve overall aircraft efficiency, reducing fuel burn and hence emissions. However, due to the poor electrical conductivity of CFRP, the CFRP structure and electrical power system (EPS) must be kept physically separate via bulky, heavy cable harnesses and raceways. The closer integration of EPS with CFRP structure offers an opportunity to optimize the weight and volume of the combined electrical power and structural systems, reducing the need for harnesses and raceways. To enable this, there is a need to understand the implications that this will have for electrical power systems design, including approaches to protection. This paper identifies candidate protection solutions for resilient, integrated electrical–composite aircraft structures, by consideration of the interdependent trades between MEA EPS architecture design, CFRP, grounding topology, and electrical fault response. The influence of these interdependent elements on protection requirements is explored, and as a result, design rules for the protection of such resilient, integrated systems are formulated and presented, enabling a focus on the fault response of the system and development of appropriate protection solutions

Electrical protection design for integrated motor drives with carbon fibre composite casings for aircraft

Replacing traditionally aluminum non-electrically active components of integrated motor drives (IMD) (e.g. casings) with lighter-weight carbon fibre reinforced polymer (CFRP) for offers a route to the key weight savings, desirable in future aircraft electric applications. However, CFRP casing designs must accommodate electrical interactions with encased equipment. Approaches to fault management and electrical protection must ensure that both electrical power system (EPS) and CFRP casing are protected against electrical faults. Knowledge of the electrical and thermal response of the CFRP casing underpins fault resilient casing design. The proposed CFRP casing is a wound filament (WF) CFRP tube for an integrated motor drive. This paper presents the first experimentally validated methodology to capture macro-scale electrical and thermal response of a WF CFRP tube to low frequency current. This knowledge is subsequently combined with wider EPS design considerations, including electrical grounding and bonding, to control fault response, enabling implementation of appropriate protection solutions. The results indicate that tuning casing resistance is not a viable, immediate option to control fault response, and that wider electrical system design options (grounding topologies) must be considered. Hence incorporation of CFRP for non-electrically active components to improve power density, has significant impact on wider electrical power system design

The electron accelerator for the AWAKE experiment at CERN

The AWAKE collaboration prepares a proton driven plasma wakefield acceleration experiment using the SPS beam at CERN. A long proton bunch extracted from the SPS interacts with a high power laser and a 10 m long rubidium vapour plasma cell to create strong wakefields allowing sustained electron acceleration. The electron bunch to probe these wakefields is supplied by a 20 MeV electron accelerator. The electron accelerator consists of an RF-gun and a short booster structure. This electron source should provide beams with intensities between 0.1 and 1 nC, bunch lengths between 0.3 and 3 ps and an emittance of the order of 2 mm mrad. The wide range of parameters should cope with the uncertainties and future prospects of the planned experiments. The layout of the electron accelerator, its instrumentation and beam dynamics simulations are presented

A route to sustainable aviation : a roadmap for the realization of aircraft components with electrical and structural multifunctionality

Increased electrification of aircraft power systems has been widely presented as a route toward meeting environmental and emissions targets for aircraft performance, via more-electric aircraft and future hybrid-electric aircraft concepts. In parallel, the superior mechanical performance of carbon fiber reinforced polymer (CFRP) has resulted in its increasing use for aircraft structures. The relatively low electrical conductivity of CFRP compared to traditional aluminum structures and copper conductors limits the use of structural CFRP structures as electrical elements, so separate systems are needed. This adds structural mass and volume to a system, negating some of the benefits of using CFRP. Closer integration of the composite structure and electrical power system (EPS), with an ultimate goal of achieving components with multifunctionality (combined thermal, electrical, and structural functionality), offers a route toward the light-weighting of these systems, thus supporting improvements in aircraft performance. This article presents a roadmap to achieve this multifunctionality, supported by the combination of introducing definitions for different levels of multifunctionality, associated design thresholds, and trades between the EPS and CFRP materials/structures. Existing multifunctional (MF) electrical-thermal-structural CFRP-based solutions are contextualized within this roadmap. This enables the realization of viable routes for developing MF systems for the strategic focus of future research efforts