Stellar binary black holes in the LISA band: a new class of standard sirens

The recent Advanced LIGO detections of coalescing black hole binaries (BHBs) imply a large population of such systems emitting at milli-Hz frequencies, accessible to the Laser Interferometer Space Antenna (LISA). We show that these systems provide a new class of cosmological standard sirens. Direct LISA luminosity distance -$D_l$- measurements, combined with the inhomogeneous redshift -$z$- distribution of possible host galaxies provide an effective way to populate the $D_l-z$ diagram at $z<0.1$, thus allowing a precise local measurement of the Hubble expansion rate. To be effective, the method requires a sufficiently precise LISA distance determination and sky localization of a sizeable number of BHBs, which is best achieved for a 6-link detector configuration. We find that, for a BHB population consistent with current fiducial LIGO rates, the Hubble constant $H_0$ can be determined at the $\sim$5% and $\sim$2% level (68% confidence) assuming two and five million Km arm-length respectively.Comment: 9 pages 4 figures, to be submitted to MNRA

Impact of Secondary Acceleration in Gamma-Ray Bursts

We discuss the acceleration of secondary muons, pions, and kaons in gamma-ray bursts within the internal shock scenario, and their impact on the neutrino fluxes. We introduce a two-zone model consisting of an acceleration zone (the shocks) and a radiation zone (the plasma downstream the shocks). The acceleration in the shocks, which is an unavoidable consequence of the efficient proton acceleration, requires efficient transport from the radiation back to the acceleration zone. On the other hand, stochastic acceleration in the radiation zone can enhance the secondary spectra of muons and kaons significantly if there is a sufficiently large turbulent region. Overall, it is plausible that neutrino spectra can be enhanced by up to a factor of two at the peak by stochastic acceleration, that an additional spectral peaks appears from shock acceleration of the secondary muons and pions, and that the neutrino production from kaon decays is enhanced. Depending on the GRB parameters, the general conclusions concerning the limits to the internal shock scenario obtained by recent IceCube and ANTARES analyses may be affected by up to a factor of two by secondary acceleration. Most of the changes occur at energies above 10^7 GeV, so the effects for next-generation radio-detection experiments will be more pronounced. In the future, however, if GRBs are detected as high-energy neutrino sources, the detection of one or several pronounced peaks around 10^6 GeV or higher energies could help to derive the basic properties of the magnetic field strength in the GRB.Comment: 10 pages, 5 figures, 1 tabl

Analysis of HOM interaction between cavities by multi-modal s-parameter measurements

Accelerating cavities exchange HOM power through interconnecting beam pipes in case of signal frequencies above the cut-off of their propagating waveguide modes. This may lead either to improved HOM damping or - in the case most severe - to unwanted phase coherence of fields to the beam. Therefore the knowledge of the scattering properties of a cavity as a line element is needed to analyse all kinds of RF cavity-cavity interaction. Since there is a lack of measurement tools capable to provide a multidimensional scattering matrix at a given frequency point, we have been developing a method for this purpose. It uses a set of 2-port S-parameters of the device under test, embedded in a number of geometrically different RF environments. The application of the method is demonstrated with copper models of TESLA cavities

Transversal loss factor of an rf-focussing iris structure with rectangular holes

By replacing the irises in an electron linac by a slit one gets a structure capable of focussing/defocussing an electron beam (rf-quadrupoles). Therefore one can think of a combination of rf- and conventional magnetic quadrupoles for transversal focussing in linear-colliders. Furthermore they can meet the demands of BNS-damping without initial energy spread. Considering multibunch-operation of a collider, the long-range wake behaviour of this kind of structure has to be investigated. A three-cell structure has been built and investigated for dipole-type transversal long-range wakes. The experimental results are compared to numerical simulations done with MAFIA

Method for the engineering of production systems by reusing modules

Anlagenbauer und -betreiber unterliegen heute einem zunehmenden Wettbewerbsdruck, der zur Folge hat, dass die Effizienz in allen Unternehmensbereichen gesteigert werden soll. Die Wiederverwendung von Modulen und dem dazugehörigen Wissen ermöglicht die Steigerung der Effizienz und die Beherrschung der Komplexität im Engineering und auch in der Fertigung von komplexen und variantenreichen Produkten. Der Ansatz der Wiederverwendung ausdetaillierter Module aus Baukästen lässt sich bislang allerdings nur bedingt auf Produktionsanlagen wie Montagelinien übertragen, die spezifisch auf den Anforderungen und Prozesse des Anlagenbetreibers angepasst sind, da die notwendige Standardisierung beispielsweise für die Definition von Modulschnittstellen für diese Systeme sehr aufwändig ist. Die Herausforderung bei der Wiederverwendung von Modulen in solchen Produktionsanlagen liegt darin, Module zu identifizieren, die so klein sind, dass sie in verschiedenen Anlagen wiederverwandt werden können, und die so groß sind, dass sie dem Entwickler einen Mehrwert gegenüber der Wiederverwendung von Komponenten bieten. Um dieser Herausforderung gerecht zu werden, wird im Rahmen dieser Arbeit eine Methode vorgestellt werden, die Entwickler bei der Identifikation von Modulen unterstützt und die die Wiederverwendung in den frühen Phasen des Engineering – also in der Konzeption einer Anlage – ermöglicht. Dazu wird ein methodisches Vorgehen entwickelt und in einer Software implementiert. Die Methode ermöglicht es dem Entwickler, wiederverwendbare Module in bestehenden Produktionsanlagen zu identifizieren. Dazu wird ein matrixbasierter Ansatz in Kombination mit Sortieralgorithmen und Bewertungskriterien genutzt. Zusätzlich werden diese Module durch Eigenschaften und Funktionen systematisiert und in einer Wissensbasis abgespeichert. Dadurch wird es ermöglicht, im Engineering neuer Produktionsanlagen Modulkombinationen durch eine Prozessbeschreibung mit Funktionen zu erstellen und durch die Vorgabe von Eigenschaften relevante Kombinationen einzugrenzen. In einem weiteren Schritt werden die Module bewertet und damit die Modulkombinationen priorisiert. Dazu wird ein aggregierter Nutzwert aus Kosten, Produktivität, Energieverbrauch und Auslastung für die Modulkombination gebildet. Durch statistische Verfahren oder Simulation ist es möglich, diese Bewertungen an die Anforderungen an eine neue Produktionsanlage anzupassen. Um den Entwickler bei der Anwendung der Methode zu unterstützen, wurde die Methode in einem Softwarewerkzeug abgebildet und in der industriellen Praxis erprobt. Die vorgestellte Methode eignet sich insbesondere für Hersteller und Betreiber prozessspezifischer Produktionsanlagen, die das Wissen über diese Anlagen im Engineering neuer oder im Reengineering bestehender Anlagen wiederverwenden wollen. Die Methode unterstützt sie nicht nur bei der Modulidentifikation und bei der Systematisierung des Wissens, sondern auch in der Bereitstellung während der Konzeptionsphase. Im Engineering wird neben der Auswahl einer geeigneten Modulkombination auch eine Bewertung vorgenommen, die in weiterführenden Schritten wie der Angebotserstellung genutzt werden kann. Der Nutzen der Wiederverwendung von Wissen wird durch die Bereitstellung von Daten zu den Modulen erhöht.Industrial machine manufacturers and operating companies are subject to an increasing competition nowadays. This results in the pursuit of greater efficiency and effectiveness in all areas of the company. The reuse of modules and the related knowledge allows increasing the efficiency and managing the complexity in engineering and in the production of complex products with many variants. The approach of reusing modules from modular systems, which are described in all details, can be transmitted only partially on production systems such as assembly lines so far. These systems are specifically adapted to the requirements and processes of the operator of the production system. This is mainly due to the standardization effort for example for the definition of module interfaces for these systems. The challenge of reuse of modules in such a production system is to identify modules which are small enough that they can be reused in different systems, and which are large enough that they offer the developer an added value, compared to the reuse of components. In this thesis, a method will be presented in order to meet this challenge. This method supports the engineer in the identification of modules, and it facilitates the reuse in the early stages of engineering or, more specifically, in the conception of a system. For this, a methodology is developed and implemented as software. The method allows the developer to identify reusable modules into existing production systems. For this purpose, a matrix-based approach is used in combination with sorting algorithms and evaluation criteria. In addition, these modules are systematized by features and functions and stored in a knowledge base. Thus, it is possible to create combinations of modules through a process description with functions in the engineering of new production and to limit the selection to relevant combinations by specifying properties. In a further step, the modules are assessed and thus the module combinations are prioritized. For this purpose, an aggregate utility value of cost, productivity, energy consumption and utilization is formed for the module combination. It is possible through statistical methods or simulation to adapt these assessments to the requirements of a new production system. The method is implemented in a software tool to assist the developer in the application of the method and tested in the industrial practice. The method is particularly suitable for manufacturers and operators of process-specific production system, who want to reuse the knowledge of these systems in the engineering of new systems or the adaption of existing systems. The method supports the user not only in the identification of modules and in the systematization of knowledge, but also in the provision of knowledge during the conceptual design phase. In addition to choosing a suitable combination of modules an assessment is carried out in engineering, which can be used in further steps, such as the quotation. The benefits of reuse of knowledge are increased by the provision of data of the modules. Due to this this knowledge can be reused not only for the modules, the interfaces and the assessment, but also on first drafts, documentation, simulation models etc.

Energy Propagation through the TESLA Channel: Measurements with Two Waveguides Modes

A new method for the determination of S-matrices of devices in multimoded waveguides and first experimental experiences are presented. The theoretical foundations are given. The scattering matrix of a TESLA copper cavity at a frequency above the cut-off of the second waveguide mode has been measured

The design of the HOM-damping cells for the S-band linear collider

Damping cells for the higher order modes are necessary for the S-band linear collider to minimize BBU (Beam-Break-Up). The construction of the damper cells has to take into account the different field geometries of the higher order modes. So two different types of dampers have been designed: a wall slotted an an iris slotted cell. In order to optimize the two types of damping cells with respect to damping strength, impedance matching between coupling system and waveguide dampers and between damping cell and undamped cells and the tuning system, damping cells of both types have been built and examinated

The effect of a single HOM-damper cell within a channel of undamped cells

The effect of a single HOM-damper cell within a channel of undamped cells is described theoretically using an equivalent circuit model. From this a simple equation can be derived which relates the Q-value of the single damping-cell, the bandwidth of the passband under consideration, and the additional phase shift which is introduced by the damper cell to provide energy flow into the damper cell. This equation immediately shows the limitations of such single cell damping systems. Comparisons with experimental results are shown

Mode propagation in an iris type accelerator section loaded with single heavily HOM-damped cells

The wakefield effects in accelerator sections for future linear colliders will be reduced either by damping by detuning or by a combination of both. For the DESY/THD linac [1] it is forseen to employ heavily HOM-damped cells to provide a strong coupling to the TE/TM11-dipole passband as well as to the TM/TE11-dipole passband. For our experiments we have used wall-slotted damping cells. This leads to several problems concerning the propagation of fundamental and HOM-modes. Experimental investigations have been done. Results are presented