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This paper presents the results of development and tests of a sideband separating heterodyne receiver for the 85-115 GHz band with superconducting tunnel junctions (SIS) as frequency down converters. Sideband separation is achieved by using a quadrature scheme where two identical mixer junctions are pumped by a local oscillator (LO) with 90° phase difference. We used an innovative mixer layout where the quadrature scheme is implemented using waveguide-based and integrated on-chip components. We employed an additional pair of SIS junctions as terminations for LO-injection directional couplers. [ABSTRACT FROM PUBLISHER]

The ROOT software framework is foundational for the HEP ecosystem, providing multiple capabilities such as I/O, a C++ interpreter, GUI, and math libraries. It uses object-oriented concepts and build-time components to layer between them. We believe that a new layering formalism will benefit the ROOT user community. We present the modularization strategy for ROOT which aims to build upon the existing source components, making available the dependencies and other metadata outside of the build system, and allow post-install additions on top of existing installation as well as in the ROOT runtime environment. Components can be grouped into packages and made available from repositories in order to provide a post-install step of missing packages. This feature implements a mechanism for the more comprehensive software ecosystem and makes it available even from a minimal ROOT installation. As part of this work, we have reduced inter-component dependencies in order to improve maintainability. The modularization effort draws inspiration from similar efforts in the Java, Python, and Swift ecosystems. Keeping aligned with modern C++, this strategy relies on forthcoming features such as C++ modules. We hope formalizing the component layer provides simpler ROOT installs, improves extensibility, and decreases the complexity of embedding ROOT in other ecosystems.

ROOT is a data analysis framework broadly used in and outside of High Energy Physics (HEP). Since HEP software frameworks always strive for performance improvements, ROOT was extended with experimental support of runtime C++ Modules. C++ Modules are designed to improve the performance of C++ code parsing. C++ Modules offers a promising way to improve ROOT’s runtime performance by saving the C++ header parsing time which happens during ROOT runtime. This paper presents the results and challenges of integrating C++ Modules into ROOT.

Collaboration in research is essential for saving time and money. The field of high-energy physics (HEP) is no different. The higher level of collaboration the stronger the community. The HEP field encourages organizing various events in format and size such as meetings, workshops and conferences. Making attending a HEP event easier leverages cooperation and dialogue and this is what makes Indico service defacto a community standard. The paper describes HEPCon, a cross-platform mobile application which collects all information available on Indico and makes it available on a portable device. It keeps most of the data locally which speeds up the interaction. HEP-Con uses a shared code base which allows easy multiplatform development and support. There are iOS and Android implementations available for free download. The project is based on C# and we use the Xamarin mobile app technology for building native iOS and Android apps. SQLite database is responsible for retrieving and storing conference data. The app can be used to preview data from past CHEP conferences but the tool is implemented generic enough to support other Indico events.

Foundational software libraries such as ROOT are under intense pressure to avoid software regression, including performance regressions. Continuous performance benchmarking, as a part of continuous integration and other code quality testing, is an industry best-practice to understand how the performance of a software product evolves. We present a framework, built from industry best practices and tools, to help to understand ROOT code performance and monitor the efficiency of the code for several processor architectures. It additionally allows historical performance measurements for ROOT I/O, vectorization and parallelization sub-systems.

The 23rd International Conference on Computing in High Energy and Nuclear Physics (CHEP) took place in the National Palace of Culture, Sofia, Bulgaria from 9th to 13th of July 2018. 575 participants joined the plenary and the eight parallel sessions dedicated to: online computing; offline computing; distributed computing; data handling; software development; machine learning and physics analysis; clouds, virtualisation and containers; networks and facilities. The conference hosted 35 plenary presentations, 323 parallel presentations and 188 posters.

In this article we consider a critical thermodynamic system with the shape of a thin film confined between two parallel planes. It is assumed that the state of the system at a given temperature and external ordering field is described by order-parameter profiles, which minimize the one-dimensional counterpart of the standard ϕ4 Ginzburg–Landau Hamiltonian and meet the so-called Neumann – Neumann boundary conditions. We give analytic representation of the extremals of this variational problem in terms ofWeierstrass elliptic functions. Then, depending on the temperature and ordering field we determine the minimizers and obtain the phase diagram in the temperature-field plane.

The behaviour of the local and total susceptibilities of a fluid system bounded by different surfaces is studied in the framework of the Ginsburg-Landau Ising type model. The case of a plain geometry, Neumann-infinity boundary conditions under variations of the temperature and an external ordering field is considered. Exact analytic expressions for the order parameter, local and total susceptibilities in such a system are presented. They are used to analyse the phase behaviour of fluids confined in regions close to the bulk critical point of the respective infinite system.