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A non-interceptive optical diagnostic system on the basis of beam tomography, was developed for the planned Frankfurt Neutron Source (FRANZ). The proton driver linac of FRANZ will provide energies up to 2.0 MeV. The measurement device will non-interceptively derive required beam parameters at the end of the LEBT at beam energies of 120 keV and a current of 200 mA. On a narrow space of 351.2 mm length a rotatable tomography tank will perform a multi-turn tomography with a high and stable vacuum pressure. The tank allows to plug different measurement equipment additionally to the CCD Camera installed, to perform optical beam tomography. A collection of developed algorithms provides information about the density distribution, shape, size, location and emittance on the basis of CCD images. Simulated, as well as measured data have been applied to the evaluation algorithms to test the reliability of the beam. The actual contribution gives an overview on the current diagnostic possibilities of this diagnostic system.
Die Bananenstaude ist schon seit Jahrtausenden in Kultur und gehört heutzutage mit zu den wichtigsten tropischen Weltwirtschaftspflanzen. Die zahlreichen Wildformen spielen dabei eine untergeordnete Rolle. Von großem wirtschaftlichen Interesse sind hingegen die Kulturbananen, die grob in zwei Klassen eingeteilt werden können: einerseits die Obstbananen und andererseits die Koch-, Stärke- oder Mehlbananen. Der vorliegende Beitrag enthält Darstellungen zu Systematik, Verbreitung, Morphologie und Kultur der Bananenstaude.
Intense ion beams with small phase space occupation (high brilliance) are mandatory to keep beam losses low in high current injector accelerators like those planned for FAIR. The low energy beam transport from the ion source towards the linac has to keep the emittance growth low and has to support the optimization of the ion source tune. The Frankfurt Neutron Source Facility FRANZ is currently under construction. An intense beam of protons (2 MeV, 200 mA) will be used for neutron production using the Li7(p,n)Be7 reaction for studies of the astrophysical s-process. A collimation channel, which can be adjusted to allow the transport of beams with a certain beam emittance, is an ideal tool to optimize the ion source tune in terms of beam brightness. Therefore a collimation channel in the Low Energy Beam Transport section will be used. Through defined apertures and transversal phase space rotation using focusing solenoids the beam halo as well as unwanted H2+ and H3+ fractions will be cut. Theoretical studies which were carried out so far and a first design of the setup will be presented.
Beam test of the direct plasma injection scheme (DPIS) is carried out successfully for the first time in China, by setting up a comprehensive test and research platform of RFQ and laser ion source. The C6+ beam is accelerated successfully, and the peak beam current reaches more than 6mA which is measured by a Faraday cup of unique structure. The RF power coupled into the RFQ cavity is also examined, and results reveal that it is the RF power of about 195kW that can produce the peak beam current.
A CW RFQ prototype
(2011)
A short RFQ prototype was built for RF-tests of high power RFQ structures. We will study thermal effects and determine critical points of the design. HF-simulations with CST Microwave Studio and measurements were done. The cw-tests with 20 kW/m RF-power and simulations of thermal effects with ALGOR were finished successfully. The optimization of some details of the HF design is on focus now. First results and the status of the project will be presented.
Beam measurements with the new RFQ beam matching section at the Frankfurt Funneling Experiment
(2011)
Funneling is a method to increase low energy beam currents in multiple stages. The Frankfurt Funneling Experiment is a model of such a stage. The experiment is built up of two ion sources with electrostatic lens systems, a Two-Beam-RFQ accelerator, a funneling deflector and a beam diagnostic system. The two beams are bunched and accelerated in a Two-Beam RFQ. A funneling deflector combines the bunches to a common beam axis. A new beam transport system between RFQ accelerator and deflector has been constructed and mounted. With these extended RFQ-electrodes the drift between the Two-Beam-RFQ and the rf-deflector will be minimized and therefore unwanted emittance growth reduced. After first rf measurements current work are beam tests with the improved Two-Beam-RFQ. First results will be presented.
Usually 4-ROD Radio Frequency Quadrupoles (RFQ) are built for frequencies up to 216 MHz. For higher frequencies 4-VANE structures are more common. The advantages of 4-Rod structures, the greater flexibility for tuning and being more comfortable for maintenance, are motivating the development of a 4-Rod RFQ for higher frequencies than 216 MHz. In particular a 325 MHz RFQ with an output energy of 3 MeV is needed for the proton linac for the FAIR project of GSI. This paper reports about the design studies and the latest developments of this RFQ.
For the injector upgrade at FNAL a 4-rod Radio Frequency Quadrupole (RFQ) with a resonance frequency of 200 MHz has been build. With this short structure of only 1.3 m a very compact injector design has been realized. Simulations with CST Microwave Studio® were performed for the design. Their results leading to the RF characterizations of the RFQ and the final RF setup which has been accomplished at IAP of the Goethe-University Frankfurt are presented in this paper.
The LANSCE linear accelerator at Los Alamos National Laboratory provides H− and H+ beams to several user facilities that support Isotope Production, NNSA Stockpile Stewardship, and Basic Energy Science programs. These beams are initially accelerated to 750 keV using Cockcroft-Walton (CW) based injectors that have been in operation for over 37 years. They have failure modes which can result in prolonged operational downtime due to the unavailability of replacement parts. To reduce long-term operational risks and to realize future beam performance goals in support of the Materials Test Station (MTS) and the Matter-Radiation Interactions in Extremes (MaRIE) Facility, plans are underway to develop a Radio-Frequency Quadrupole (RFQ) based front end as a modern injector replacement for the existing CW injectors. Our progress to date will be discussed.
n order to reach the desired intensities of heavy ion beams for the experiments at FAIR, SIS18 and SIS100 have to be operated with intermediate charge states. Operation with intermediate charge state heavy ions at the intensity level of about 1011 ions per cycle has never been demonstrated elsewhere and requires a dedicated upgrade program for SIS18 and a dedicated machine design for SIS100. The specific problems coming along with the intermediate charge state operation in terms of charge exchange processes at collisions with residual gas atoms, pressure bumps by ion induced desorption and corresponding beam loss appears far below the typical space charge limits. Thus, new design concepts and new technical equipment addressing these issues are developed and realized with highest priority. The upgrade program of SIS18 addressing the goal of minimum ionization beam loss and stable residual gas pressure conditions has been defined in 2005. A major part of this upgrade program has been successfully realized, with the result of a world record in accelerated number of intermediate charge state heavy ions.
Accelerator Driven Systems (ADS) are promising tools for the efficient transmutation of nuclear waste products in dedicated industrial installations, called transmuters. The Myrrha project at Mol, Belgium, placed itself on the path towards these applications with a multipurpose and versatile system based on a liquid PbBi (LBE) cooled fast reactor (80 MWth) which may be operated in both critical and subcritical modes. In the latter case the core is fed by spallation neutrons obtained from a 600 MeV proton beam hitting the LBE coolant/target. The accelerator providing this beam is a high intensity CW superconducting linac which is laid out for the highest achievable reliability. The combination of a parallel redundant and of a fault tolerant scheme should allow obtaining an MTBF value in excess of 250 hours that is required for optimal integrity and successful operation of the ADS. Myrrha is expected to be operational in 2023. The forthcoming 4-year period is fully dedicated to R&D activities, and in the field of the accelerator they are strongly focused on the reliability aspects and on the proper shaping of the beam trip spectrum.
Development of fragmented low-Z ion beams for the NA61 fixed-target experiment at the CERN SPS
(2011)
The NA61 experiment, aims to study the properties of the onset of deconfinement at low SPS energies and to find signatures of the critical point of strongly interacting matter. A broad range in T-μB phase diagram will be covered by performing an energy (13A-158A GeV/c) and system size (p+p, Be+Be, Ar+Ca, Xe+La) scan. In a first phase, fragmented ion beams of 7Be or 11C produced as secondaries with the same momentum per nucleon when the incident primary Pb-ion beam hits a thin Be target will be used. The H2 beam line that transports the beam to the experiment acts as a double spectrometer which combined with a new thin target (degrader) where fragments loose energy proportional to the square of their charge allows the separation of the wanted A/Z fragments. Thin scintillators and TOF measurement for the low energy points are used as particle identification devices. In this paper results from the first test of the fragmented ion beam done in 2010 will be presented showing that a pure Be beam can be obtained satisfying the needs of the experiment.
Space charge lenses using a stable electron cloud for focusing low energy heavy ion beams are an alternative concept to conventional ion optics. Due to external fields electrons are confined inside the lens’ volume. In case of a homogeneously distributed electron cloud the linear electric space charge field enables beam focusing free of aberration. Since the mapping quality of the lens is related to the confinement, non-destructive diagnostics has been developed to determine the plasma parameters and to characterize the collective behavior of the confined nonneutral plasma. Moreover, a scaled up space charge lens was constructed for a detailed investigation of the nonneutral plasma properties as well as beam interactions with a stable confined electron cloud. Experimental results will be presented in comparison with numerical simulations.
As the successor of the EUROTRANS project, the MAX project is aiming to continue the R&D effects for a European Accelerator-Driven System and to bring the conceptual design to reality. The layout of the driver linac for MAX will follow the reference design made for the XT-ADS phase of the EUROTRANS project. For the injector part, new design strategies and approaches, e.g. half resonant frequency, half transition-energy between the RFQ and the CH-DTL, and using the 4-rod RFQ structure instead of the originally proposed 4-vane RFQ, have been conceived and studied to reach a more reliable CW operation at reduced costs. In this paper, the design and simulation results of the MAX injector are presented.
MYRRHA is conceived as an accelerator driven system (ADS) for transmutation of high level nuclear waste. The neutron source is created by coupling a proton accelerator of 600 MeV with a 4 mA proton beam, a spallation source and a sub-critical core. The IAP of Frankfurt University is responsible for the development of the 17 MeV injector operated at 176 MHz. The injector consists of a 1.5 MeV 4-Rod-RFQ and six CH-drifttube-structures. The first two CH-structures will be operated at room temperature and the other CH-structures are superconducting cavities assembled in one cryo-module. To achieve the extremely high reliability required by the ADS application, the design of the 17 MeV injector has been intensively studied, with respect to thermal issues, minimum peak fields and field distribution.
Chromatic, geometric and space charge effects on laser accelerated protons focused by a solenoid
(2011)
We studied numerically emittance and transmission effects by chromatic and geometric aberrations, with and without space charge, for a proton beam behind a solenoid in the laser proton experiment LIGHT at GSI. The TraceWin code was employed using a field map for the solenoid and an initial distribution with exponential energy dependence close to the experiment. The results show a strong effect of chromatic, and a relatively weak one of geometric aberrations as well as dependence of proton transmission on distance from the solenoid. The chromatic effect has an energy filtering property due to the finite radius beam pipe. Furthermore, a relatively modest dependence of transmission on space charge is found for p production intensity below 1011.
Experimental results and theoretical predictions in laser acceleration of protons achieved energies of ten to several tens of MeV. The LIGHT project (Laser Ion Generation, Handling and Transport) is proposed to use the PHELIX laser accelerated protons and to provide transport, focusing and injection into a conventional accelerator. This study demonstrates transport and focusing of laser-accelerated 10 MeV protons by a pulsed 18 T magnetic solenoid. The effect of co-moving electrons on the beam dynamics is investigated. The unique features of the proton distribution like small emittances and high yield of the order of 1013 protons per shot open new research area. The possibility of creating laser based injectors for ion accelerators is addressed. With respect to transit energies, direct matching into DTL's seems adequate. The bunch injection into a proposed CH− structure is under investigation at IAP Frankfurt. Options and simulation tools are presented.
An optimized design of a stellarator-type storage ring for low energy ion beams was numerically investigated. The magnetic field variation along the circumference and therefore magnetic heating is suppressed by using simple circular correction coils. Particle-in-Cell (PIC) simulations in a magnetic flux coordinate system show the ability of high current ion beam accumulation in such a configuration with unique features for clockwise and anticlockwise moving beams. Additionally scaled down experiments with two 30 degree room temperature toroidal segments were performed to demonstrate toroidal transport and to develop optical beam diagnostics. Properties of multi-component beams, redistribution of transversal momenta in the non-adiabatic part of the experimental configuration and investigation of strongly confined beam induced electron clouds will be addressed.
For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. The main acceleration of this room temperature linac will be provided by six CH cavities operated at 325 MHz. Each cavity will be powered by a 2.5 MW Klystron. For the second acceleration unit from 11.5 MeV to 24.2 MeV a 1:2 scaled model has been built. Low level RF measurements have been performed to determine the main parameters and to prove the concept of coupled CH cavities. For this second tank technical and mechanical investigations have been performed in 2010 to develop a complete technical concept for the manufacturing. In Spring 2011, the construction of the first power prototype has started. The main components of this cavity will be ready for measurements in summer 2011. At that time, the cavity will be tested with a preliminary aluminum drift tube structure, which will allow precise frequency and field tuning. This paper will report on the recent technical development and achievements. It will outline the main fabrication steps towards that novel type of proton DTL. Also first low level RF measurements are expected.
The MYRRHA Project (Multi Purpose Hybrid Reactor for High Tech Applications) at Mol/belgium will be a user facility with emphasis on research with neutron generated by a spallation source. One main aspect is the demonstration of nuclear waste technology using an accelerator driven system. A superconducting linac delivers a 4 mA, 600 MeV proton beam. The first accelerating section is covered by the 17 MeV injector. It consists of a proton source, an RFQ, two room temperature CH cavities and 4 superconducting CH-cavities. The initial design has used an RF frequency of 352 MHz. Recently the frequency of the injector has been set to 176 MHz. The main reason is the possible use of a 4-rod-RFQ with reduced power dissipation and energy, respectively. The status of the overall injector layout including cavity design is presented.
SIS100 is the main synchrotron of the FAIR project. It is designed to accelerate high intensity intermediate charge state uranium beams from 200 MeV/u up to 2.7 GeV/u. Intermediate charge state heavy ions are exposed to a high probability of charge exchange due to collisions with residual gas molecules. Since the charge exchange process changes the magnetic rigidity, the involved ions are lost behind dispersive elements, and an energy-dependent gas desorption takes place. The StrahlSim code has been used to predict the stability of the residual gas pressure in SIS100 under beam loss driven dynamic conditions. The results show, that a stable operation at highest U28+ intensities is possible, under the constraint that the vacuum chambers of the ion catcher system are cold enough to pump hydrogen. Furthermore, in order to determine the load to the cryogenic system, the average beam energy deposition onto the ion catcher system has been calculated.
The ARMADILLO bunch compressor currently being designed at IAP is capable of reaching a longitudinal pulse compression ratio of 45 for proton beams of 150 mA at 2 MeV. It will provide one nanosecond proton pulses with a peak current of 7.7 A. The system guides nine linacμbunches deflected by a 5 MHz rf kicker and uses four dipole magnets - two homogeneous and two with field gradients - to merge them on the target. For longitudinal focusing and an energy variation of ±200 keV two multitrack rf cavities are included. ARMADILLO will be installed at the end of the Frankfurt Neutron Source FRANZ making use of the unique 250 kHz time structure. This contribution will provide an overview of the layout of the system as well as recent advances in component design and beam dynamics of the compressor.
At the Institute for Applied Physics (IAP), University of Frankfurt, a s.c. 325 MHz CH-Cavity is under development for future beam tests at GSI UNILAC, Darmstadt. The cavity with 7 accelerating cells has a geometrical beta of 0.15 corresponding to 11.4 AMeV. The design gradient is 5 MV/m. The geometry of this resonator was optimized with respect to a compact design, low peak fields, surface processing, power coupling and tuning. Furthermore a new tuning system based on bellow tuners inside the resonator will control the frequency during operation. After rf tests in Frankfurt the cavity will be tested with a 10 mA, 11.4 AMeV beam delivered by the GSI UNILAC. In this paper rf simulations, multipacting analysis as well as thermal calculations will be presented.
On the clay plains surrounding Lake Chad (West Africa: northern Sudanian and southern Sahelian zone), certain varieties of pearl millet (Sorghum bicolor), commonly referred to as Masakwa, are cultivated during the dry season. Recently fallowed Masakwa fields support a particular progression of pioneer vegetation. In the first year of fallow, the pioneer vegetation typically belongs to the class Echinochloetea colonae Wittig 2005 and can be classified as Hygrophiletum auriculatae sensu lato. Approximately half of the stands consist of the Hygrophiletum auriculatae Ataholo 2002 sensu stricto, whereas the other half is primarily composed of a Celosia argentea-Hibiscus trionum community. After two years of fallow, the vegetation is typically formed by the Sorghetum arundinacei Ataholo 2002, which, in a few cases, can also occur in the first fallow year.
The use of woody species of rural populations in Northern Benin was investigated by semi-structured and open interviews. Of the 129 woody species found in the area, 124 (96%) were mentioned to be used as firewood, for house and furniture construction or preparation of tools, for alimentation, in traditional medicine and/or for other purposes. Our study confirms and underlines the high importance of non timber forest products (NTFPs) for the local population.
The SIS300 synchrotron, planned for the new Facility for Antiproton and Ion Research (FAIR) at GSI-Darmstadt, will become the first superconducting synchrotron worldwide using cos(θ) magnets for resonant slow extraction. A multi-objective optimization algorithm has been developed for the design of the non-linear magnet scheme. The optimization algorithm makes use of the analytical model for the slow extraction from Kobayashi, the analytical description of the resonance excitation and amplitude-dependent tune-shift from Bengtsson, and corrects the chromaticity in order to fulfill the Hardt condition. As a result, the placement of the chromatic and harmonic sextupole magnets in SIS300, the number of sextupole families and the gradients of these families have been optimized for a high efficiency slow extraction. The algorithm accounts also for the sextupole errors on the dipole magnets, compensating its effects. Furthermore, optimized time-dependent settings for the sextupole magnets are generated to compensate the persistent current decay occurring at slow extraction. Tolerances for the magnets are set for the limits where the compensation is no longer valid.
Chopper systems are used to pulse charged particle beams. In most cases, electric deflection systems are used to generate beam pulses of defined lengths and appropriate repetition rates. At high beam intensities, the field distribution of the chopper system needs to be adapted precisely to the beam dynamics in order to avoid aberrations. An additional challenge is a robust design which guarantees reliable operation. For the Frankfurt Neutron Source FRANZ, an E×B chopper system is being developed which combines static magnetic deflection with a pulsed electric field in a Wien filter configuration. It will generate proton pulses with a flat top of 50 ns at a repetition rate of 250 kHz for 120 keV, 200 mA beams. For the electric deflection, pre-experiments with static and pulsed fields were performed using a helium ion beam. In pulsed mode operation, ion beams of different energies were deflected with voltages of up to ±6 kV and the resulting response was measured using a beam current transformer. A comparison between experiments and theoretical calculations as well as numerical simulations are presented.
A modern linear accelerator of ions is a long chain of different accelerating-focusing structures. The design of new linacs, as well as an upgrade and optimization of operating facilities, requires precise and reliable beam matching with the subsequent sections. Proper matching of the beam to the channel allows to improve the performance of the whole linac and to reduce the specific costs. Additionally it helps to avoide particle loss in high energy high intensity linacs. Generally a matching algorithm combines precisely measured or calculated accelerating-focusing external fields and experimentally obtained details of the beam parameters with an advanced code for beam dynamics simulations including space charge effects. Experimental results are introduced into a code as input data. The described algorithm has already been successfully implemented for several GSI projects: an upgrade of the GSI heavy ion linac UNILAC, an ion linac for the cancer therapy, the proton linac for the FAIR facility, a facility for laser acceleration of ions and others. Measured data and results of beam dynamics simulations leading to an achieved improvement of the linac performance are presented.
At GSI a new, superconducting (sc) continuous wave (cw) LINAC is under design in cooperation with the Institute for Applied Physics (IAP) of Frankfurt University and the Helmholtz Institut Mainz (HIM). This proposed LINAC is highly requested by a broad community of future users to fulfill the requirements of nuclear chemistry, nuclear physics, and especially in the research field of Super Heavy Elements (SHE). In this context the preliminary layout of the LINAC has been carried out by IAP. The main acceleration of up to 7.3 AMeV will be provided by nine sc Crossbar-H-mode (CH) cavities operated at 217 MHz. Currently, a prototype of the cw LINAC as a demonstrator is under development. The demonstrator comprises a sc CH-cavity embedded between two sc solenoids mounted in a horizontal cryomodule. A full performance test of the demonstrator in 2013/14 by injecting and accelerating a beam from the GSI High Charge Injector (HLI) is one important milestone of the project. The status of the demonstrator is presented.
The superconducting CH-structure (Crossbar-H-mode) is a multi-cell drift tube cavity for the low and medium energy range operated in the H21-mode, which has been developed at the Institute for Applied Physics (IAP) of Frankfurt University. With respect to different high power applications two types of superconducting CH-structures (f = 325 MHz, β = 0.16, seven cells and f = 217 MHz, β = 0.059, 15 cells) are presently under construction and accordingly under development. The structural mechanical simulation is a very important aspect of the cavity design. Furthermore, several simulations with ANSYS Workbench have been performed to predict the deformation of the cavity walls due to the cavity cool-down, pressure effects and mechanical vibrations. To readjust the fast frequency changes in consequence of the cavity shape deformation, a new concept for the dynamic frequency tuning has been investigated, including a novel type of bellow-tuner.
In Deutschland sind Paranüsse besonders in der Advents- und Weihnachtszeit als Knabberei und als Dekoartikel sehr beliebt. Der Paranussbaum, der seinen Namen nach dem brasilianischen Bundestaat Pará bzw. dem gleichnamigen Ausfuhrhafen erhielt, war ursprünglich in den tropischen Regenwäldern Südamerikas verbreitet; es wird jedoch mittlerweile auch versucht, ihn plantagenmäßig in Südostasien und im tropischen Afrika anzubauen. Die Biologie und Nutzung werden im vorliegenden Beitrag beschrieben.
The Frankfurt Neutron Source at the Stern-Gerlach-Zentrum is driven by a 2 MeV proton linac consisting of a 4-rod-radio-frequency-quadrupol (RFQ) and an 8 gap IH-DTL structure. RFQ and IH cavity will be powered by only one radio frequency (RF) amplifier to reduce costs. The RF-amplifier of the RFQ-IH combination is coupled into the RFQ. Internal inductive coupling along the axis connects the RFQ with the IH cavity ensuring the required power transition as well as a fixed phase relation between the two structures. The main acceleration of 120 keV up to 2.03 MeV will be reached by the RFQ-IH combination with 175 MHz and at a total length of 2.3 m. The losses in the RFQ-IH combination are about 200 kW.
This novel kind of neutron beam facility will provide 1 ns short neutron pulses with an approximately thermal energy distribution around 30 keV. The pulse repetition rate will be up to 250 kHz, the total proton number per pulse will be up to 6×1010 in the final stage, starting with a p – source current of 200 mA. A second target station will allow n – activation experiments by cw beam operation. An intense 2 MeV proton beam will drive a neutron source by the 7 Li (p,n) 7 Be reaction. The facility is under construction at the physics experimental hall of the J.W. Goethe – University. The 1m thick concrete tunnel was installed in 2009. In 2011 all rf amplifiers will be delivered and installed. Successful 200 mA proton source experiments in 2010 at a test stand will be followed by experiments on the 120 kV FRANZ terminal in 2011. The 250 kHz, 100 ns chopper in front of the rf linac is under construction, while the 2 MeV bunch compressor design was finished and the technical design of all components has started. The main accelerator cavity is under construction. First 2 MeV beam tests are expected for end of 2012.
Mit dieser Arbeit konnte die Funktionsweise von gekoppelten Resonatoren erklärt werden. Das Verhalten von induktiv gekoppelten Beschleunigerkavitäten wurde näher studiert. Dabei wurde verstanden, wie sich Verstimmungen auf die Resonatoren auswirken und was zu tun ist um die Spannungsamplituden des gekoppelten Systems zu beeinflussen. Zudem wurden die Grundlagen für den gekoppelten Betrieb des FRANZ-Beschleunigers gelegt.
Als Adalbert Stifters Roman „Der Nachsommer“ 1857 erscheint, hat das Bild der klassischen Antike, wie es durch Winckelmann und Goethe einen hohen Grad der Verbindlichkeit erhalten hatte, längst an Faszination und normativer Kraft eingebüßt. Im Gefolge des Historismus, der jeder Epoche ihr Eigenrecht zuerkannte, waren historische Vorstellungen an die Stelle normativer getreten. In Stifters „Nachsommer“ ist davon freilich nur wenig zu spüren. Der Roman wendet sich ostentativ gegen aktuelle Zeittendenzen und scheint für ein Festhalten an einer zeitlos-idealen Antike einzutreten. Die ausführlichen Gespräche, die der Ich-Erzähler Heinrich Drendorf mit seinem Gastgeber Risach über antike Kunst führt, wiederholen und zementieren überkommene Auffassungen. In Superlativen beschwört Risach Größe und Einfachheit der antiken Kunst; er nennt die griechische Dichtung „das Höchste“ und „was die Griechen in der Bildnerei geschaffen haben, [...] das Schönste, welches auf der Welt“ überhaupt bestehe. Stifters Antike orientiert sich, wie in der Forschung einhellig anerkannt, an Leitvorstellungen Winckelmanns, und die im „Nachsommer“ geführten Kunstgespräche treten in die Spuren der ästhetischen Debatten des ausgehenden 18. Jahrhunderts.
Allein in einer entlegenen Klassikerausgabe des Jahres 1921 findet man, was man in der Forschungsliteratur vergeblich sucht: den Versuch, Friedrich Hölderlins „Hyperion“ und Carl Rottmanns griechische Landschaftsbilder einander anzunähern oder zumindest zu vergleichen. Rottmanns Gemälde und Hölderlins Roman werden zu Recht zu den eigenwilligsten und produktivsten Schöpfungen des deutschen Philhellenismus gezählt, und doch ist – soweit ich sehe – in der literaturwissenschaftlichen und kunsthistorischen Forschung noch nie nach einem engeren Zusammenhang zwischen beiden Werken gefragt worden. Trennt Hölderlins Roman, der in zwei Teilen 1797 und 1799 erschien, und Rottmanns Gemäldezyklus, der in den Jahren 1838 bis 1850 entstand, tatsächlich ein allzu großer zeitlicher Abstand? Zeichnen beide Werke gänzlich verschiedene Bilder Griechenlands, sodass sich jeder Vergleich verbietet?
Das christliche Bild im 19. Jahrhundert zeigt, so die These dieses Aufsatzes, dass Verwissenschaftlichung nicht notwendigerweise historistische Entidealisierung bedeuten musste – wie eben auch die Lektion der historisch-kritischen Bibelforschung nicht unweigerlich zu einer Relativierung der Heiligen Schrift führen musste. In der ästhetischen Konstruktion der biblischen Antiken wurden Evidenz und Imagination zu komplementären Repräsentationsstrategien, die einen gemeinsamen Ursprung jenseits der Unterscheidung zwischen geschichtlicher Wahrheit und archäologischem Wissen hatten. Eine christliche Kunst musste diese historische Wahrheit, die eben keine wissenschaftlich positivistische sein sollte, sichtbar machen. „Das Göttliche kann sich in der Knechtsgestalt begränzter Zeit und Körperlichkeit nicht völlig offenbaren“, formulierte Karl Schnaase im Jahre 1862 diesen Grundsatz eindringlich, „es will mehr geahnt und geglaubt als gesehen sein“. Zwischen archäologischer Treue und kunsthistorischer Tradition, mimetischer Sinnlichkeit und abstrakter Idee erfüllt die Kunst ihre ureigene Aufgabe des Sichtbarmachens im Bewusstsein einer eingeborenen Unmöglichkeit. Die Welt der biblischen Antike wird so zum experimentellen Feld eines erfolgreichen Scheiterns.
Im Spektrum der Epochen, von denen der Historienroman im 19. Jahrhundert erzählt, spielt die Antike eine untergeordnete Rolle. Ihr vorgezogen werden die großen Zeitalter der nachantiken europäischen Geschichte: das hohe Mittelalter, die Renaissance, die Frühe Neuzeit und die Revolutionsepoche um und nach 1800. Erst gegen Ende des 19. Jahrhunderts, lange nach der sogenannten „Scott-Ära“ in den 1820er Jahren, in denen sich der historische Roman in ganz Europa zur beliebtesten Erzählform entwickelt, wird häufiger über die Antike erzählt. So steigt die Zahl der Romane, welche die antike Geschichte thematisieren, gegen Ende der sechziger Jahre des 19. Jahrhunderts langsam und kontinuierlich an bis zu einem Höhepunkt in den 1880er Jahren, um danach wieder leicht zurückzufallen. Auch in den 1880er Jahren bleibt die jährliche Publikationsrate von Romanen über das Altertum freilich im einstelligen Bereich und damit deutlich unterhalb der Quote je- ner Texte, die sich späteren historischen Zeiträumen widmen. Themen aus der Phase zwischen Barockzeitalter und beginnendem 19. Jahrhundert dominieren die gesamte Epoche; bestimmend ist die Tendenz zu jüngeren Zeitabschnitten, zur modernen Geschichte.
Das Spannungsverhältnis zwischen poetischer Einbildungskraft und positivistischer Wissenschaft, zwischen Imagination und Evidenz, wird wohl an keinem anderen literarischen Genre des 19. Jahrhunderts so augenfällig wie am historischen Roman. Schon in der Gattungsbezeichnung verbinden sich die Lizenzen der Fiktionalität, die der Roman gewährt, mit einem wie auch immer gearteten Anspruch auf historische Faktizität. Die unüberschaubare Menge der historischen Romane, die im 19. Jahrhundert entstand, spiegelt in den vielfältigen Sujets und Figuren nicht nur die Interessen- und Problemlagen ihrer Entstehungszeit wider, sondern liefert im Zeitalter des ästhetischen Historismus ganz unterschiedliche Beispiele von textuellen Verfahren, die das Verhältnis von Imagination und Evidenz sichtbar machen.
Wem gehört die Geschichte? : Fakten und Fiktionen in der neueren deutschen Erinnerungsliteratur
(2011)
This essay discusses the distinct features of memory fiction, a new genre that has emerged during the last two decades. It works through memories of the Nazi past and traumatic episodes of the Second World War within new literary frameworks. In this orientation towards the past the memory novel maintains distance from the research of historical reconstruction, as well as from the popular presentation of the past in the visual mass media. With respect to the new literary genre, various questions arise concerning its status and quality. One of these concerns the distinction anti interplay between fictional and documentary features in the new format. Another one has to do with the emphasis on biographical experience that in many cases has become an important trigger and source for the text, endowing it with the stamp of authenticity or moral authority. It is also true, however, that war-related experience, trauma and suffering can no longer be claimed by members of the second and third generation who either write their own lives into the chain of generations connected with the Second World War and the Holocaust, or create a new access to central events of the traumatic national history from the perspective of a fictional private family. In both ways they testify to the aftermath of the traumatic past which, as they show, is still part of the present.
The concept of the “magic circle” (Johan Huizinga) defines the stage and the specific performative conditions for magic to work. This concept which was applied by Huizinga to spaces such as the courtroom, the church or the theatre is extended in this essay to the page of the literary text. It is argued that something of the age-old magic of oral poetry is preserved in contemporary German memory fiction that stages an encounter with dead family members. In novels by Peter Härtling (Nachgetragene Liebe) and Uwe Timm (Am Beispiel meines Bruders) a repressed past is emotionally revisited and at the same time exposed to new reflection in the light of hindsight. The therapeutic setting of “family constellation” is introduced as another manifestation of the magic circle in our contemporary world in which latent traumas are acted out and worked through in a cathartic process.
The virgin Mary and Eve constitute two opposite sexual poles in the way Christian discourse has approached women since the time of the church fathers. This stems from a predicament faced by the human male throughout hominid evolution, namely, paternal uncertainty. Because the male is potentially always at risk of unwittingly raising the offspring of another male, two (often complementary) male sexual strategies have evolved to counter this genetic threat: mate guarding and promiscuity. The Virgin Mary is the mythological expression of the mate guarding strategy. Mary is an eternal virgin, symbolically allaying all fear of paternal uncertainty. Mary makes it possible for the male psyche to have its reproductive cake and eat it too: she gives birth (so reproduction takes place) and yet requires no mate guarding effort or jealousy. Eve, the inventor of female sexuality, is repeatedly viewed by the church fathers, e.g., Augustine and Origen, as Mary's opposite. Thus, Eve becomes the embodiment of the whore: both attractive in the context of the promiscuity strategy and repulsive in terms of paternal uncertainty: "Death by Eve, life by Mary" (St. Jerome). The Mary-Eve dichotomy has given a conceptual basis to what is known in psychology as the Madonna-Whore dichotomy: the tendency to categorize women in terms of two polar opposites. This paper will explore the way mythology reflects biology, i.e., human psychological traits that have evolved over millennia.
During a fieldtrip to Hordaland in Norway, I collected Fissidens serrulatus in one place: Norway, Hordaland, Skanevik, steep slope along road between highway E 134 and village, birch forest, on seeping rocks of a cliff, ca. 90 m alt. leg. Frahm Sept. 1, 2011, no. 2011676. The specimen was collected because of the large size of the plants and to check, whether they belong to F. adianthoides or F. dubius. In fact, F. serrulatus looks much alike these species mentioned, also under the microscope, showing a pale band of cells along the leaf margins, but differs under the microscope by strongly mamillose laminal cells (fig. 3).
Im Untersuchungsgebiet „Rußigmühle“ im Nationalpark „Sächsische Schweiz“ wurden drei freistehende Laubbäume mit Hilfe der Seilklettertechnik auf ihre Epiphytenflora untersucht. Von den insgesamt 44 Epiphyten (24 Flechten und 20 Moose) konnten mit der klassischen Kartiermethode bis 2 Meter Reichhöhe nur 28 Arten (64%) nachgewiesen werden, 16 Arten (36%) fanden sich ausschließlich im höheren Stammbereich und Kronenraum. Eine zeitgleich durchgeführte klassische Kartierung des ca. 0,5 ha großen Untersuchungsgebietes zeigte, dass der Großteil dieser Kronenepiphyten an anderen Gehölzen in Reichhöhe wuchs bzw. auf herabgefallenem Bruchholz nachgewiesen werden konnte. Der Nachweis der Flechten Evernia prunastri und Phaeophyscia orbicularis und des Mooses Ptilidium pulcherrimum im Untersuchungsgebiet gelang ausschließlich durch die Kronenkartierung.
Based on collections by the author made in September 2001, Conocephalum salebrosum, Hydrogonium ehrenbergii, Breutelia chrysocoma and Campylopus pilifer var. brevirameus are reported as new to the Azores. Seven species are reported as new to Sâo Miguel. Various notes and keys are provided for several taxa.
Das Trollbachtal beherbergt eines der bedeutendsten Moosvorkommen im unteren Nahetal. Untersuchungen in den Jahren 1992 bis 2011 ergaben 206 Arten, von denen 71 (34%) zu den Rote-Liste-Arten zählen. Die Artenvielfalt ist das Ergebnis vielfältiger Habitate und Böden. Das Untersuchungsgebiet besteht neben bewirtschafteten Bereichen (Weinbergen) aus einem hohen Anteil an älteren Brachen (ehemalige Weinberge), naturnahe Areale enthalten kleine Quellhorizonte und Bäche, Trockenrasen, besonnte und beschattete Felsabhänge und Felsen. Bemerkenswerte Taxa sind Crossidium squamiferum, Eurhynchium pulchellum, Fissidens exiguus, Mannia fragrans, Phascum vlassovii, Pottia mutica und Tortula papillosissima var. submamillosa. Aufgrund überwiegend xerothemer Standorte dominieren Trockniszeiger mit 110 Spezies, von denen fast ein Drittel (31%) aus submediterranen Arealen stammt. An beschatteten Felshängen überraschen die boreal/dealpinen Arten Leiocolea alpestris und Scapania aequiloba. Eine Gefährdung der Moose besteht vor allem in der Sukzession von Sträuchern und Bäumen in Felstrockenrasen
Das Naturschutzgebiet Haarberg-Höllberg ist mit einer Fläche von 38 ha eines der größten Schutzgebiete der Rheinhessischen Schweiz. Untersuchungen in den Jahren 2008 bis 2011 ergaben auf den saueren und nährstoffarmen Böden einen Besatz mit 133 Moosen, von denen 29 (22%) als Rote-Liste-Arten eingestuft sind. Taxa von besonderer Bedeutung sind Grimmia montana, Phascum curvicolle, Phascum cuspidatum var. papillosum, Rhynchostegium megapolitanum und Tortula crinita. Aus einem Arealtypenspektrum ist zu ersehen, dass neben überwiegend temperaten Arten boreal/subboreale, subozeanische und submediterrane Arten zu etwa gleichen Anteilen vorkommen. Dieses wird durch die Vielfalt der Landschaftsstrukturen erklärt. Mit 8 Arten sind Lebermoose selten, sie finden in den xerothermen Biotopen kaum Lebensmöglichkeiten. Der stärkste Bedrohungsfaktor ist die Sukzession von Sträuchern und Bäumen, besonders die Schlehe (Prunus spinosa) hat bereits größere Flächen der Felstrockenrasen erobert.