Suchergebnisse

Integrated Circuits are used in most people's lives in the modern societies. An important branch of research and technology is focused on Integrated Circuit (IC) design, fabrication, and their efficient applications; moreover most of these activities are about commercial productions with applications in ambient environment. However the ICs play very important role in very advance research fields, as Astronomy or High Energy Physics experiments, with absolutely extreme environments which require very interdisciplinary research orientations and innovative solutions. For example, the Fast TracKer (FTK) electronic system, which is an important part of triggering system in ATLAS experiment at European Organization for Nuclear Research (CERN), in every second of experiment selects 200 interesting events among 40 millions of total events due to collision of accelerated protons. The FTK function is based on ICs which work as Content Addressable Memory (CAM). A CAM compares the income data with stored data and gives the addresses of matching data as an output. The amount of calculation in FTK system is out of capacity of commercial ICs even in very advanced technologies, therefore the development of innovative ICs is required. The high power consumption due to huge amount of calculation was an important limitation which is overcome by an innovative architecture of CAM in this dissertation. The environment of ICs application in astrophysics and High Energy Physics experiments is different from commercial ICs environment because of high amount of radiation. This fact started to get seriously attention after the first "Telstar I" satellite failure because of electronic damages due to radiation effects in space, and opened a new field of research mostly about radiation hard electronics. The multidisciplinary research in radiation hard electronic field is about radiation effects on semiconductors and ICs, deep understanding about the radiation in the extreme environments, finding alternative solutions to increase the radiation tolerance of electronic components, and development of new simulation method and test techniques. Chapter 2 of this dissertation is about the radiation effects on Silicon and ICs. Moreover, In this chapter, the terminologies of radiation effects on ICs are explained. In chapter 3, the space and high energy physics experiments environments, which are two main branches of radiation hard electronics research, are studied. The radiation tolerance in on-chip circuits is achieving by two kinds of methodology: Radiation Hardening By Process (RHBP) and Radiation Hardening By Design (RHBD). RHBP is achieved by changing the conventional fabrication process of commercial ICs. RHBP is very expensive so it is out of budget for academic research, and in most cases it is exclusive for military application, with very restricted rules which make the access of non-military organizations impossible. RHBD with conventional process is the approach of radiation hard IC design in this dissertation. RHBD at hardware level can be achieved in different ways: • System level RHBD: radiation hardening at system level is achieved by algorithms which are able to extract correct data using redundant information. •Architecture level RHBD: some hardware architectures are able to prevent of lost data or mitigate the radiation effects on stored data without interfacing of software. Error Correction Code (ECC) circuits and Dual Interlocked storage CEll (DICE) architecture are two examples of RHBD at architecture level. • Circuit level RHBD: at circuit level, some structures are avoided or significantly reduced. For example, feedback loops with high gain are very sensitive to radiation effects. • Layout level RHBD: there are also different solutions in layout design level to increase the radiation tolerance of circuits. Specific shapes of transistor design, optimization of the physical distance between redundant data and efficient polarization of substrate are some techniques commonly used to increase significantly the radiation tolerance of ICs. An innovative radiation hard Static Random Access Memory (SRAM), designed in three versions, is presented in chapter 4. The radiation hardening is achieved by RHBD approach simultaneously at architecture, circuit and layout levels. Complementary Metal-Oxide-Semiconductor (CMOS) 65 nm is the technology of design and the prototype chip is fabricated at Taiwan Semiconductor Manufacturing Company (TSMC). Chapter 5 is about the development of simulation models that can help to predict the radiation effect in the behavior of SRAM block. The setup system developed to characterize the radiation hard SRAM prototype chip is presented in Chapter 5. The setup system gives the possibility of testing the prototype exposed under radiation in a vacuum chamberand regular laboratory environment. Chapter 6 is about the contribution of this dissertation on FTK project and the conclusion of all research activities is shown in the final part of this dissertation. The research activities of this dissertation in supported by Italian National Institute for Nuclear Physics (INFN) as part of CHIPIX65 project and RD53 collaboration at CERN.

String theory is canonically accompanied with a space-time interpretation which determines S-matrix-like observables, and connects to the standard physics at low energies in the guise of local effective field theory. Recently, we have introduced a reformulation of string theory which does not rely on an a priori space-time interpretation or a pre-assumption of locality. This metastring theory is formulated in such a way that stringy symmetries (such as T-duality) are realized linearly. In this paper, we study metastring theory on a flat background and develop a variety of technical and interpretational ideas. These include a formulation of the moduli space of Lorentzian worldsheets, a careful study of the symplectic structure and consequently consistent closed and open boundary conditions, and the string spectrum and operator algebra. What emerges from these studies is a new quantum notion of space-time that we refer to as a quantum Lagrangian or equivalently a modular space-time. This concept embodies the standard tenets of quantum theory and implements in a precise way a notion of relative locality. The usual string backgrounds (non-compact space-time along with some toroidally compactified spatial directions) are obtained from modular space-time by a limiting procedure that can be thought of as a correspondence limit. ; U.S. Department of Energy [DE-FG02-13ER42001, DE-FG02-13ER41917] ; Government of Canada through NSERC ; Province of Ontario through MRI ; We thank L. Anderson, P. Argyres, V. Balasubramanian, B. Basso, D. Berman, R. Blumenhagen, M. Buric, F. Cachazo, S. Caron-Huot, L. N. Chang, T. Curtright, M. Cvetic, S. Das, M. Duff, E. Gimon, J. Gomis, J. Gray, M. Gunaydin, A. Hanany, J. Heckman, P. Horava, Y. Hui-He, C. Hull, V. Jejjala, T. Kephart, M. Kruczenski, D. Lust, J. Madore, J. Maldacena, L. McAllister, R. Myers, L. Pando Zayas, O. Parrikar, J. Polchinski, R. Plesser, S. Ramgoolam, R. Roiban, W. Siegel, K. Sfetsos, E. Sharpe, A. Shapere, R. Szabo, T. Takeuchi, W. Taylor, C. Thorn, A. Tseytlin, C. Tze, H. Verlinde, D. Vaman, P. Vieira, C. Zachos and B. Zwiebach for discussions, comments and communications. RGL and DM thank Perimeter Institute for hospitality. RGL is supported in part by the U.S. Department of Energy contract DE-FG02-13ER42001 and DM by the U.S. Department of Energy under contract DE-FG02-13ER41917. Research at Perimeter Institute for Theoretical Physics is supported in part by the Government of Canada through NSERC and by the Province of Ontario through MRI.

We explore Seiberg-like dualities, or mutations, for quiver quantum mechanics in the context of wall-crossing. In contrast to higher dimensions, the 1d Seiberg-duality must be performed with much care. With fixed Fayet-Iliopoulos constants, at most two nodes can be mutated, one left and the other right, mapping a chamber of a quiver into a chamber of a mutated quiver. We delineate this complex pattern for triangle quivers and show how the Witten indices are preserved under such finely chosen mutations. On the other hand, the quiver invariants, or wall-crossing-safe part of supersymmetric spectra, mutate more straightforwardly, whereby a quiver is mapped to a quiver. The mutation rule that preserves the quiver invariant is different from the usual one, however, which we explore and confirm numerically. ; NSF [PHY-1417316] ; Perimeter Institute for Theoretical Physics ; Government of Canada through Industry Canada ; Province of Ontario through the Ministry of Economic Development and Innovation ; John Templeton Foundation ; NSF [PHY-1417316] ; Perimeter Institute for Theoretical Physics ; Government of Canada through Industry Canada ; Province of Ontario through the Ministry of Economic Development and Innovation ; John Templeton Foundation ; We are indebted to Kentaro Hori and Zhao-Long Wang for useful conversations, and Kyungyong Lee for extensive discussions of the Cluster Algebra. H.K. and S-J.L. are grateful to Korea Institute for Advanced Study for hospitality. The work of S.-J.L. is supported in part by NSF grant PHY-1417316. H.K. was supported by the Perimeter Institute for Theoretical Physics. Research at Perimeter Institute is supported by the Government of Canada through Industry Canada and by the Province of Ontario through the Ministry of Economic Development and Innovation. The work of H.K. was made possible through the support of a grant from John Templeton Foundation. The opinions expressed in this publication are those of the author and do not necessarily reflect the views of the John Templeton Foundation.

This paper contributes to the literature on the impact of Big Science Centres on technological innovation. We exploit a unique dataset with information on CERN's procurement orders to study the collaborative innovation process between CERN and its industrial partners. After a qualitative discussion of case studies, survival and count data models are estimated; the impact of CERN procurement on suppliers' innovation is captured by the number of patent applications. The fact that firms in our sample received their first order over a long-time span (1995-2008) delivers a natural partition of industrial partners into "suppliers" and "not yet suppliers". This allows to estimate the impact of CERN on the hazard to file a patent for the first time and on the number of patent applications, as well as the time needed for these effects to show up. We find that a "CERN effect" does exist: being an industrial partner of CERN is associated with an increase in the hazard to file a patent for the first time and in the number of patent applications. These effects require a significant "gestation lag" in the range of five to eight years, pointing to a relatively slow process of absorption of new ideas.

We address the validity of the usual procedure to determine the sensitivity of neutrino oscillation experiments to CP violation. An explicit calibration of the test statistic is performed through Monte Carlo simulations for several experimental setups. We find that significant deviations from a chi(2) distribution with one degree of freedom occur for experimental setups with low sensitivity to ffi. In particular, when the allowed region to which ffi is constrained at a given confidence level is comparable to the whole allowed range, the cyclic nature of the variable manifests and the premises of Wilk's theorem are violated. This leads to values of the test statistic significantly lower than a chi(2) distribution at that confidence level. On the other hand, for facilities which can place better constraints on ffi the cyclic nature of the variable is hidden and, as the potential of the facility improves, the values of the test statistics first become slightly higher than and then approach asymptotically a chi(2) distribution. The role of sign degeneracies is also discussed. ; Goran Gustafsson Foundation ; U.S. Department of Energy [DE-SC0003915] ; European Union [PCIG11-GA-2012-321582] ; ITN INVISIBLES [PITN-GA-2011-289442] ; Spanish MINECO [RYC2011-07710, FPA2009-09017] ; We are very grateful to Thomas Schwetz for valuable discussions and encouragement. We warmly thank Peter Ballett for pointing out an inconsistency in the treatment of the systematic errors in the first version of the manuscript, and Pilar Hernandez for illuminating discussions. This work was supported by the Goran Gustafsson Foundation [MB] and by the U.S. Department of Energy under award number DE-SC0003915 [PC]. EFM acknowledges financial support by the European Union through the FP7 Marie Curie Actions CIG NeuProbes (PCIG11-GA-2012-321582) and the ITN INVISIBLES (PITN-GA-2011-289442), and the Spanish MINECO through the "Ramon y Cajal" programme (RYC2011-07710) and through the project FPA2009-09017. We also thank the Spanish MINECO (Centro de excelencia Severo Ochoa Program) under grant SEV-2012-0249 as well as the Nordita Scientific program "News in Neutrino Physics", where part of this work was performed.

The ESS nu SB project is a proposed neutrino oscillation experiment based on the European Spallation Source with the search for leptonic CP violation as its main aim. In this letter we show that a near detector at around 1 km distance from the beamline is not only very desirable for keeping the systematic errors affecting the CP search under control, but would also provide a significant sensitivity probe for sterile neutrino oscillations in the region of the parameter space favored by the long-standing LSND anomaly. We find that the effective mixing angle theta(mu e) can be probed down to sin(2)(2 theta(mu e)) similar or equal to 2(8) . 10(-3) at 5 sigma assuming 15% bin-to-bin (un) correlated systematics. ; Goran Gustafsson Foundation ; U.S. Department of Energy [DE-SC0003915] ; European Union through FP7 Marie Curie Actions CIG NeuProbes [PCIG11-GA-2012-321582] ; European Union through ITN INVISIBLES [PITN-GA-2011-289442] ; Spanish MINECO through "Ramon y Cajal" programme [RYC2011-07710] ; Spanish MINECO [FPA2009-09017] ; Spanish MINECO (Centro de excelencia Severo Ochoa Program) [SEV-2012-0249] ; This work has been supported by the Goran Gustafsson Foundation [MB], and by the U.S. Department of Energy under award number DE-SC0003915 [PC]. EFM acknowledges financial support by the European Union through the FP7 Marie Curie Actions CIG NeuProbes (PCIG11-GA-2012-321582) and the ITN INVISIBLES (PITN-GA-2011-289442), and the Spanish MINECO through the "Ramon y Cajal" programme (RYC2011-07710) and through the project FPA2009-09017. We also thank the Spanish MINECO (Centro de excelencia Severo Ochoa Program) under grant SEV-2012-0249 as well as the Nordita Scientific program "News in Neutrino Physics", where this work was initiated.