84 research outputs found

    Demonstration of fine pitch FCOB (Flip Chip on Board) assembly based on solder bumps at Fermilab

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    Bump bonding is a superior assembly alternative compared to conventional wire bond techniques. It offers a highly reliable connection with greatly reduced parasitic properties. The Flip Chip on Board (FCOB) procedure is an especially attractive packaging method for applications requiring a large number of connections at moderate pitch. This paper reports on the successful demonstration of FCOB assembly based on solder bumps down to 250um pitch using a SUESS MA8 flip chip bonder at Fermilab. The assembly procedure will be described, microscopic cross sections of the connections are shown, and first measurements on the contact resistance are presented.Comment: 4 pages, 8 figure

    Status of a DEPFET pixel system for the ILC vertex detector

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    We have developed a prototype system for the ILC vertex detector based on DEPFET pixels. The system operates a 128x64 matrix (with ~35x25 square micron large pixels) and uses two dedicated microchips, the SWITCHER II chip for matrix steering and the CURO II chip for readout. The system development has been driven by the final ILC requirements which above all demand a detector thinned to 50 micron and a row wise read out with line rates of 20MHz and more. The targeted noise performance for the DEPFET technology is in the range of ENC=100 e-. The functionality of the system has been demonstrated using different radioactive sources in an energy range from 6 to 40keV. In recent test beam experiments using 6GeV electrons, a signal-to-noise ratio of S/N~120 has been achieved with present sensors being 450 micron thick. For improved DEPFET systems using 50 micron thin sensors in future, a signal-to-noise of 40 is expected.Comment: Invited poster at the International Symposium on the Development of Detectors for Particle, AstroParticle and Synchrotron Radiation Experiments, Stanford CA (SNIC06) 6 pages, 12 eps figure

    Readout Concepts for DEPFET Pixel Arrays

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    Field effect transistors embedded into a depleted silicon bulk (DEPFETs) can be used as the first amplifying element for the detection of small signal charges deposited in the bulk by ionizing particles, X-ray photons or visible light. Very good noise performance at room temperature due to the low capacitance of the collecting electrode has been demonstrated. Regular two dimensional arrangements of DEPFETs can be read out by turning on individual rows and reading currents or voltages in the columns. Such arrangements allow the fast, low power readout of larger arrays with the possibility of random access to selected pixels. In this paper, different readout concepts are discussed as they are required for arrays with incomplete or complete clear and for readout at the source or the drain. Examples of VLSI chips for the steering of the gate and clear rows and for reading out the columns are presented.Comment: 8 pages, 9 figures, submitted to Nucl. Instr. and Methods as proceedings of the 9th European Symposium on Semiconductor Detectors, Elmau, June 23-27, 200

    Die prognostische Relevanz des Nachweises disseminierter Tumorzellen im Knochenmark und in Lymphknoten Level I nodal-negativer Mammakarzinompatientinnen

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    Fragestellung: Der Nachweis von CK+-KMM ist ein unabhängiger Prognosefaktor, der das primär auf den LK_Status ausgerichtete, aktuelle Tumorstaging beeinflussen könnte. In der vorliegenden Studie wurde untersucht, ob CK+-KMM und LKM parallel nachweisbar und jeweils prognostisch Relevant sind. Methode: 300 KM-Aspirate und 1590 axilläre Level I LK von 150 nodal-negativer Patientinnen wurden mit monoklonalen anti-CK Antikörpern (A45-B/B3 und NCL-5D3) prospektiv analysiert und mit etablierten Prognosefaktoren verglichen. Die mediane Beobachtungszeit betrug 39 Monate Ergebnisse: CK+-KMM fanden sich bei 44/150 (29%)und CK+-LKM bei 13/150 (9%) Patientinnen. ein CK+-Befund korrelierte nicht mit den etablierten Prognosefaktoren. Der Nachweis von CK+-KMM war nicht mit locoregionären Rezidiven aber mit Fernmetastasierung und tumorabhängigen Tod assoziiert. Der immunzytochemische LKM-Nachweis hatte keine prognostische Bedeutung. In der multiarianten Analyse blieb die CK-Positivität des KM ein unabhängiger Prognosefaktor mit einer Hazard-Ratio von 6,1 für ein verkürztes Gesamtüberleben. Schlussfolgerung: Hämatogene, nicht jedoch lymphogene Mikrometastasierung scheint ein unabhängiger Prognosefaktor für nodal-negative Patientinnen zu sein. Dies könnte als Stratifizierungskriterium in adjuvanten Therapiestudien eingesetzt werden und zukünftige chirurgische Strategien beeinflussen

    Die prognostische Relevanz des Nachweises disseminierter Tumorzellen im Knochenmark und in Lymphknoten Level I nodal-negativer Mammakarzinompatientinnen

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    Fragestellung: Der Nachweis von CK+-KMM ist ein unabhängiger Prognosefaktor, der das primär auf den LK_Status ausgerichtete, aktuelle Tumorstaging beeinflussen könnte. In der vorliegenden Studie wurde untersucht, ob CK+-KMM und LKM parallel nachweisbar und jeweils prognostisch Relevant sind. Methode: 300 KM-Aspirate und 1590 axilläre Level I LK von 150 nodal-negativer Patientinnen wurden mit monoklonalen anti-CK Antikörpern (A45-B/B3 und NCL-5D3) prospektiv analysiert und mit etablierten Prognosefaktoren verglichen. Die mediane Beobachtungszeit betrug 39 Monate Ergebnisse: CK+-KMM fanden sich bei 44/150 (29%)und CK+-LKM bei 13/150 (9%) Patientinnen. ein CK+-Befund korrelierte nicht mit den etablierten Prognosefaktoren. Der Nachweis von CK+-KMM war nicht mit locoregionären Rezidiven aber mit Fernmetastasierung und tumorabhängigen Tod assoziiert. Der immunzytochemische LKM-Nachweis hatte keine prognostische Bedeutung. In der multiarianten Analyse blieb die CK-Positivität des KM ein unabhängiger Prognosefaktor mit einer Hazard-Ratio von 6,1 für ein verkürztes Gesamtüberleben. Schlussfolgerung: Hämatogene, nicht jedoch lymphogene Mikrometastasierung scheint ein unabhängiger Prognosefaktor für nodal-negative Patientinnen zu sein. Dies könnte als Stratifizierungskriterium in adjuvanten Therapiestudien eingesetzt werden und zukünftige chirurgische Strategien beeinflussen

    2D Detectors for Particle Physics and for Imaging Applications

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    The demands on detectors for particle detection as well as for medical and astronomical X-ray imaging are continuously pushing the development of novel pixel detectors. The state of the art in pixel detector technology to date are hybrid pixel detectors in which sensor and read-out integrated circuits are processed on different substrates and connected via high density interconnect structures. While these detectors are technologically mastered such that large scale particle detectors can be and are being built, the demands for improved performance for the next generation particle detectors ask for the development of monolithic or semi-monolithic approaches. Given the fact that the demands for medical imaging are different in some key aspects, developments for these applications, which started as particle physics spin-off, are becomming rather independent. New approaches are leading to novel signal processing concepts and interconnect technologies to satisfy the need for very high dynamic range and large area detectors. The present state in hybrid and (semi-)monolithic pixel detector development and their different approaches for particle physics and imaging application is reviewed

    News, intelligence and 'little lies' : rumours between the Cherokees and the British 1740-1785

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    Rumour and information are one of the most fundamental ways in which people engage with one another. Rumours can change the way that individuals and groups see each other and the actions that they take. Sociologists and anthropologists have long used rumour as a way to explore the experiences of their subjects. Historians of early America have, in recent years, begun to make use of rumour as a way of examining the, often hidden, world of interactions between American Indians and white Europeans. This thesis will expand upon this work by exploring the changing role of rumour within an intercultural relationship over several decades. This thesis will focus on rumour in the relationship between the Cherokee Nation and the colonists of the British Empire. It will explore the ways that rumour influenced these interactions and the impact of the rapidly changing backcountry environment of the latter eighteenth century, both on rumour and on the wider Cherokee- British relationship. This thesis will argue that rumour shifted in the course of the eighteenth century from being a diplomatic tool which could be used- either to create further panic and confusion or to calm and smooth over problems- to an uncontrollable force which would deepen and exacerbate the divisions between Cherokees and the British. Rumour played an important role in politics and society in the eighteenth century backcountry and its changing function offers a way to better understand the shifting currents of life in early America

    Design and technology of DEPFET pixel sensors for linear collider applications

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    Abstract The performance requirements of vertex detectors for future linear collider experiments is very challenging, especially for the detector's innermost sensor layers. The DEPleted Field Effect Transistor (DEPFET), combining detector and amplifier operation, is capable to meet these requirements. A silicon technology is presented which allows production of large sensor arrays consisting of linear DEPFET detector structures. The envisaged pixel array offers low noise and low power operation. To ensure a high radiation length a thinning technology based on direct wafer bonding is proposed

    Description and performance of track and primary-vertex reconstruction with the CMS tracker

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    A description is provided of the software algorithms developed for the CMS tracker both for reconstructing charged-particle trajectories in proton-proton interactions and for using the resulting tracks to estimate the positions of the LHC luminous region and individual primary-interaction vertices. Despite the very hostile environment at the LHC, the performance obtained with these algorithms is found to be excellent. For tbar t events under typical 2011 pileup conditions, the average track-reconstruction efficiency for promptly-produced charged particles with transverse momenta of pT > 0.9GeV is 94% for pseudorapidities of |η| < 0.9 and 85% for 0.9 < |η| < 2.5. The inefficiency is caused mainly by hadrons that undergo nuclear interactions in the tracker material. For isolated muons, the corresponding efficiencies are essentially 100%. For isolated muons of pT = 100GeV emitted at |η| < 1.4, the resolutions are approximately 2.8% in pT, and respectively, 10μm and 30μm in the transverse and longitudinal impact parameters. The position resolution achieved for reconstructed primary vertices that correspond to interesting pp collisions is 10–12μm in each of the three spatial dimensions. The tracking and vertexing software is fast and flexible, and easily adaptable to other functions, such as fast tracking for the trigger, or dedicated tracking for electrons that takes into account bremsstrahlung
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