Achtung, Zensur! : über Meinungsfreiheit und ihre Grenzen /

Includes bibliographical references

Der Gardasee und die Deutschen. Literatur – Kunst – Kommunikation / I Tedeschi e il Garda. Letteratura – Arte – Comunicazione

Il volume affronta la storia complessa e intricata del rapporto fra i Tedeschi e il Garda e si propone come dialogo interdisciplinare e interculturale fra letteratura e linguistica, storia dell'arte e storia della cultura. Oggetto dei contributi è il Lago di Garda nella letteratura, nel cinema, nella pittura, nell'architettura, nella lingua del turismo e nella storia politica. Al centro della riflessione vi è la peculiarità del Benaco come luogo liminare: il lago è spazio di confine, ora astratto ora concreto, che unisce e al contempo separa il Nord e il Sud.Dieser Sammelband geht der komplexen und intrikaten Geschichte der Beziehung der Deutschen zum Gardasee nach. Er versteht sich als interdisziplinäres Gespräch von interkultureller Literatur- und Sprachwissenschaft, Kultur- und Kunstgeschichte. Die Beiträge untersuchen Literatur, Film, Malerei, Architektur, Tourismussprache und politische Geschichte des Gardasees. Zentral ist dabei die Liminalität des Gardasees: Er erscheint als konkrete und abstrakte Grenze, die Nord und Süd zugleich trennt und verbindet

Operation of FLASH with Short SASE-FEL Radiation Pulses

This paper describes the experimental activity on the generation of very short FEL pulses in the soft x-ray range in the SASE-mode at the high-gain free-electron laser FLASH [1, 2]. The key element, a photo-injector laser which is able to generate laser pulses of about 2 ps FWHM has been optimized and commissioned. It allows the generation of shorter bunches with low bunch charge (of up to 200 pC) directly at the photo-cathode. Initially shorter injector laser pulses and thus shorter bunches eases the required bunch compression factor for short pulses below 10 fs duration which makes operation of the electron beam formation system to be more robust with respect to jitters and collective effects. As a result, overall stability of SASE FEL performance is improved. In the optimal case single-spike operation can be achieved. In this paper the experimental results on production of short electron bunches and the SASE performance using the new injector laser will be shown and the measured electron bunch and FEL radiation properties are discussed. In addition, optimizations of bunch diagnostics for low charge and short bunches are discussed

Suppression of FEL Lasing by a Seeded Microbunching Instability

Collective effects and instabilities due to longitudinal space charge and coherent synchrotron radiation can degrade the quality of the ultra-relativistic, high-brightness electron bunches driving free-electron lasers (FELs). In this contribution, we demonstrate suppression of FEL lasing induced by a laser-triggered microbunching instability at the free-electron laser FLASH. The interaction between the electron bunches and the 800-nm laser pulses takes place in an undulator upstream of the FEL undulators. A significant decrease of XUV photon pulse energies has been observed in coincidence with the laser-electron overlap in the modulator. We discuss the underlying mechanisms based on longitudinal space charge amplification (LSCA) [E.A. Schneidmiller and M.V. Yurkov, Phys. Rev. ST Accel. Beams 13, 110701 (2010)] and present measurements

Demonstration of SASE Suppression Through a Seeded Microbunching Instability

Collective effects and instabilities due to longitudinal space charge and coherent synchrotron radiation can degrade the quality of the ultra-relativistic, high-brightness electron bunches needed for the operation of free-electron lasers. In this contribution, we demonstrate the application of a laser-induced microbunching instability to selectively suppress the SASE process. A significant decrease of photon pulse energies was observed at the free-electron laser FLASH in coincidence with overlap of 800 nm laser pulses and electron bunches within a modulator located approximately 40 meters upstream of the undulators. We discuss the underlying mechanisms based on longitudinal space charge amplification [E.A. Schneidmiller and M.V. Yurkov, Phys. Rev. ST Accel. Beams 13, 110701 (2010)] and present measurements