Studies of the Micro-Bunching Instability in the Presence of a Damping Wiggler

At the KIT storage ring KARA (Karlsruhe Research Accelerator), the momentum compaction factor can be reduced leading to natural bunch lengths in the ps range. Due to the high degree of longitudinal compression, the micro-bunching instability arises. During this longitudinal instability, the bunches emit bursts of intense coherent synchrotron radiation in the THz frequency range caused by the complex longitudinal dynamics. The temporal pattern of the emitted bursts depends on given machine parameters, like momentum compaction factor, acceleration voltage, and damping time. In this paper, the influence of the damping time is studied by utilizing the CLIC damping wiggler prototype installed in KARA as well as by simulations using the Vlasov-Fokker-Planck solver Inovesa

Studies of the Micro-Bunching Instability in the Presence of a Damping Wiggler

At the KIT storage ring KARA (Karlsruhe Research Accelerator), the momentum compaction factor can be reduced leading to natural bunch lengths in the ps range. Due to the high degree of longitudinal compression, the micro-bunching instability arises. During this longitudinal instability, the bunches emit bursts of intense coherent synchrotron radiation in the THz frequency range caused by the complex longitudinal dynamics. The temporal pattern of the emitted bursts depends on given machine parameters, like momentum compaction factor, acceleration voltage, and damping time. In this paper, the influence of the damping time is studied by utilizing the CLIC damping wiggler prototype installed in KARA as well as by simulations using the Vlasov-Fokker-Planck solver Inovesa

100 Gbit/s electro-optic modulator and 56 Gbits/s wavelength converter for DQPSK data in silicon-organic hybrid (SOH) technology

CMOS-compatible silicon photonics combined with covers of chi (2) or chi (3)-nonlinear organic material allows electro-optic modulators and all-optical wavelength converters for data rates of 100 Gbit/s and beyond. The devices are not impaired by free carriers

Investigating polarisation and shape of beam microwave signals at the ANKA storage ring

At the ANKA synchrotron radiation facility measure- ments in the microwave range (10 to 12 GHz) employing a LNB (Low Noise Block), which is the receiving part of a Satellite-TV system, have been carried out. Experiments showedthattheobservedsignaldependsonthelengthofthe electron bunches. Furthermore the temporal shape of the microwave signal depends on the detector’s position along the accelerator. Due the LNB antenna’s sensitivity to po- larisation it was also possible to measure the polarisation along the several ns long signal, revealing polarised and non-polarised regions. This paper describes the experimen - tal setup and summarises the observations of the systematic studies performed with the LNB system

Impacts of climate change on plant diseases – opinions and trends

There has been a remarkable scientific output on the topic of how climate change is likely to affect plant diseases in the coming decades. This review addresses the need for review of this burgeoning literature by summarizing opinions of previous reviews and trends in recent studies on the impacts of climate change on plant health. Sudden Oak Death is used as an introductory case study: Californian forests could become even more susceptible to this emerging plant disease, if spring precipitations will be accompanied by warmer temperatures, although climate shifts may also affect the current synchronicity between host cambium activity and pathogen colonization rate. A summary of observed and predicted climate changes, as well as of direct effects of climate change on pathosystems, is provided. Prediction and management of climate change effects on plant health are complicated by indirect effects and the interactions with global change drivers. Uncertainty in models of plant disease development under climate change calls for a diversity of management strategies, from more participatory approaches to interdisciplinary science. Involvement of stakeholders and scientists from outside plant pathology shows the importance of trade-offs, for example in the land-sharing vs. sparing debate. Further research is needed on climate change and plant health in mountain, boreal, Mediterranean and tropical regions, with multiple climate change factors and scenarios (including our responses to it, e.g. the assisted migration of plants), in relation to endophytes, viruses and mycorrhiza, using long-term and large-scale datasets and considering various plant disease control methods