Real-time control of beam parameters

This article gives an overview of the theory and application of real-time control of accelerator beams. The design and structure of orbit feedbacks are described, going from basic local feedbacks to modern state-of-the art global systems. The time domain behaviour is analysed for the building blocks of the systems as well as from the spectrum of random sources driving the orbit perturbations. The use of predictive ltering is shown for the design of the control algorithm. A second important class is the control of tunes and chromaticities. Advanced tune measurements are performed using a digital phase-locked loop. The feedback systems are typically hybrid, simultaneously working on tune and coupling and chromaticity. Adaptive feed-forward algorithms are shown to be a suitable approach for use in energy ramping. For application in a high-speed bunch-by-bunch feedback system, ef cient low-noise data processing is presented for a digital lter. Also here, predictive ltering is shown to give well-adapted high-order lters

Modeling a 30 GHz waveguide loaded detuned structure for the compact linear collider (CLIC)

One of the major challenges in designing a multi bunch structure for the Compact Linear Collider Study CLIC are the long range transverse wake fields, which couple the transverse motion of adjacent bu nches and lead to instabilities. To the most part, possible solutions, which suppress the long range wake, require a mechanical precision, which is difficult to achieve for the high fundamental freque ncy of 30 GHz. A possible way out of this dilemma consists of combining a loose detuning with the strong damping provided by radial waveguide loads. For this type of structure, an equivalent circuit m odel has been developed, which simulates the behavior of the total structure for the lower two dipole bands. The circuit parameters are derived from the results of numerical field calculations. Mismat ch of the waveguide loads is incorporated in the circuit model via a table of scattering parameters. Using this model, a first 'skeleton' design has been done. Requiring only a limited performance of the waveguide loads, this design shows a sufficient suppression of the transverse long range wakes

2018 Super Bowl

This paper is dedicated to the Super Bowl that will be held in Minneapolis, Minnesota in February of 2018. It introduces the organization responsible for the planning of the event, the event itself; as well as describes the venue in which the game will be played. The paper also includes marketing strategies for the event, suggestions to minimize risks, methods to manage employees, and discusses an ethical issue dealing with the event, as well as a personal reflection on the project and program

Seawater transfer alters the intestinal microbiota profiles of Atlantic salmon (Salmo salar L.)

This study was funded by a BBSRC Eastbio PhD studentship to CED and BBSRC grant BB/M026604/1. The authors wish to thank Ana Rita Sancho Silva for facilitating the sampling for the experiment. Furthermore we would like to express our gratitude to Ian and Alastair Fraser for their support at the SFF fish farms on the Isle of Mull.Peer reviewedPublisher PD

The Socio-Technical Dynamics of Renewable Energy Policies in Germany

Growing environmental concerns and human-caused climate change increase the pressure on policymakers for rapid action to transform how societies convert energy, produce goods, or transport freight. Innovation and technological progress may contribute to such transitions. However, technological change is hard to predict, requires time, and may be laden with political conflicts. Although more sustainable technologies are available, incentivizing demand and deployment are crucial to accelerate transitions. As transformations develop over decades, understanding the temporal dynamics of policies is critical for governance. In Germany, the renewable energy act incentivizes the deployment of renewable energy technologies by remunerating electricity fed into the common grid. This dissertation assesses how socio-technical developments of solar and wind energy conversion technologies and the renewable energy act interactively shaped each other. Drawing on frameworks such as technological innovation systems, legitimacy, framing, and policy feedback, the contents of 16,485 newspaper articles and additional empirical studies were scrutinized. Combining methods from natural language processing, machine learning, and statistics, this thesis develops text models to assess changes in content and sentiment in large corpora over time. Three studies focus on the shifts in media framing of the German renewable energy act, the underlying co-evolution of technological and policy processes, and the development of the legitimacy of wind power. The results confirm that renewable energy deployment and policy are contested with varying intensity over time. Where change ought to occur, non-linear dynamics of innovation and technology uptake, growing policy costs, economic interests of incumbents, and technology side effects increasingly complicate policymaking over time. The early phases of the renewable energy act were shaped by positive expectations toward renewable energy technologies, which later shifted towards an emphasis on policy costs. The findings highlight the importance of the prosperity of underlying innovation systems as supporters of policy ambition and maintenance over time. However, policy costs and side effects must be managed effectively to withstand increasing contestation. These results may contribute to advancing the successful governance of sectoral transitions likely to unfold over several decades

Buffalo Nation: American Indian Efforts to Restore the Bison

Review of: "Buffalo Nation: American Indian Efforts to Restore the Bison," by Ken Zontek

Design of a RF Gun for Heavy Beam Loading

For the drive beam generation of the CLIC Test Facility, a RF photo electron gun is required to generate a charge of 1 uC in a train of 48 bunches. The extracted beam energy of 6.5 J leads to a pronounced decrease of the field gradient, causing strong variations in the transverse and longitudinal beam dynamics. The drop in beam momentum yields a variation in focusing of the following solenoid leading to a blow-up of the transversal emittance. A second effect is the change of the bunch spacing caused by differing bunch velocities. These effects are to a large extent determined by the beam loading in the first cell, which contains the photo cathode. In order to reduce this effect with moderate expense of RF power, a new gun design has been developed using a TM02 resonance in the first cell followed by two standard TM01 cells. Beam simulations show that with this gun, the overall change in the longitudinal bunch spacing can be strongly reduced. Also the chromatic effects in the solenoid due to the drop in longitudinal momentum are partially compensated

Evaluation of photovoltaic storage systems on energy markets under uncertainty using stochastic dynamic programming

The rising share of intermittent renewable energy production in energy systems increasingly poses a threat to system stability and the price level in energy markets. However, the effects of renewable energy production onto electricity markets also give rise to new business opportunities. The expected increase in price differences increases the market potential for storage applications and combinations with renewable energy production. The value of storage depends critically on the operation of the storage system. In this study, we evaluate large-scale photovoltaic (PV) storage systems under uncertainty, as renewable energy production and electricity prices are fundamentally uncertain. In comparison to households who largely consume the stored energy themselves, the major business case for large-scale PV and storage systems is arbitrage trading on the electricity markets. The operation problem is formulated as a Markov decision process (MDP). Uncertainties of renewable energy production are integrated into an electricity price model using ARIMA-type approaches and regime switching. Due to non-stationarity and heteroskedasticity of the underlying processes, an appropriate stochastic modeling procedure is developed. The MDP is solved using stochastic dynamic programming (SDP) and recombining trees (RT) to reduce complexity taking into account the different time scales in which decisions have to be taken. We evaluate the solution of the SDP problem against Monte Carlo simulations with perfect foresight and against a storage dispatch heuristic. The program is applied to the German electricity and reserve power market to show the potential increase in storage value with higher price spreads, and evaluate a possible imposition of the feed-in levy onto energy directly stored from the common grid