21 research outputs found

    Testing the Untestable: A Realistic Vision of Fearlessly Testing (Almost) Every Single Accelerator Component Without Beam and Continuous Deployment Thereof

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    Whenever a bug in some piece of software or hardware stops beam operation, loss of time is rarely negligible and the cost (either in lost luminosity or real financial one) might be significant. Optimization of the accelerator availability is a strong motivation to avoid such kind of issues. Still, even at large accelerator labs like CERN, release cycles of many accelerator components are managed in a "deploy and pray" manner. In this paper we will give a short general overview on testing strategies used commonly in software development projects and illustrate their application on accelerator components, both hardware and software. Finally, several examples of CERN systems will be shown on which these techniques were or will be applied (LHC Beam-Based Feedbacks and LHC Luminosity Server) and describe why it is worth doing so

    A framework for online analysis based on Tensorics Expressions and Streaming Pool

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    Among other functionalities, the tensorics library provides a framework to declaratively describe expressions of arbitrary values and resolve these expressions in different contexts. The Streamingpool framework provides a comfortable way to transform arbitrary signals from devices into long-living reactive streams. The combination of these two concepts provides a powerful tool to describe modules for online analysis. In this paper we describe this approach, elaborate on the general concepts and give an overview of actual and potential use cases as well as ideas and plans for future evolution

    Tensorics - A Java library for manipulating multi-dimensional data

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    Accelerator control software often has to handle multi-dimensional data of physical quantities when aggregating readings from multiple devices (e.g. the reading of an orbit in the LHC). When storing such data as nested hashtables or lists, the ability to do structural operations or calculations along an arbitrary dimensions is hampered. Tensorics is a Java library that provides a solution for these problems. A Tensor is a n-dimensional data structure, and both structural (e.g. extraction) and mathematical operations are possible along any dimension. Any Java class or interface can serve as a dimension, with coordinates being instances of a dimension class. This contribution will elaborate on the design and the functionality of the Tensorics library and highlight existing use cases in operational LHC control software, e.g. the LHC luminosity server or the LHC chromaticity correction application

    Renovation of the Beam-Based Feedback Controller in the LHC

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    This work presents an extensive overview of the design choices and implementation of the Beam-Based Feedback System (BBFS) used in operation until the LHC Run 2. The main limitations of the BBFS are listed and a new design called BFCLHC, which uses the CERN Front-End Software Architecture (FESA), framework is proposed. The main implementation details and new features which improve upon the usability of the new design are then emphasised. Finally, a hardware agnostic testing framework developed by the LHC operations section is introduced

    Phase Advance Interlocking Throughout the Whole LHC Cycle

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    Each beam of CERN's Large Hadron Collider (LHC) stores 360 MJ at design energy and design intensity. In the unlikely event of an asynchronous beam dump, not all particles would be extracted immediately. They would still take one turn around the ring, oscillating with potentially high amplitudes. In case the beam would hit one of the experimental detectors or the collimators close to the interaction points, severe damage could occur. In order to minimize the risk during such a scenario, a new interlock system was put in place in 2016. This system guarantees a phase advance of zero degrees (within tolerances) between the extraction kicker and the interaction point. This contribution describes the motivation for this new system as well as the technical implementation and the strategies used to derive appropriate tolerances to allow sufficient protection without risking false beam dump triggers

    Staphylococcus aureus Nasal Colonization in Preoperative Orthopaedic Outpatients

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    Nasal colonization with Staphylococcus aureus (SA) increases the risk of surgical site infection (SSI). We first (1) determined the prevalence of asymptomatic nasal colonization with SA, (2) assessed trends in methicillin resistance with time, (3) ascertained risk factors for nasal colonization; and (4) correlated SSI to nasal colonization status and procedure. We performed a cross-sectional analysis of SA nasal colonization among healthy preoperative orthopaedic outpatients between 2003–2005 who were within 2 weeks of surgery. Of 284 patients, 86 (30%) carried SA; of these, 81 (94%) were colonized with methicillin-sensitive and five (6%) with methicillin-resistant SA (MRSA). Total SA colonization increased from 25/78 (32%) in 2003 to 37/97 (38%) in 2005, and colonization with MRSA increased from 0/78 (0%) to four of 97 (4%), respectively. We found no associations between nasal carriage and demographics or procedures. Surgical site infection occurred in nine of 282 (3%), four of which were attributable to SA; these included 0/43 (0%) carriers who received decolonization with 2% mupirocin, two of 43 (4.7%) who declined decolonization, and two of 196 (1.0%) who were noncarriers. Nasal colonization with SA, including MRSA, among preoperative orthopaedic outpatients is increasing and their rates reflect community rates. Knowledge of colonization status may be important in decolonization, choosing perioperative or any subsequent empiric antibiotics

    Online coupling measurement and correction throughout the LHC cycle

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    With high intensity beams, a precise measurement and effective correction of the betatron coupling is essential for the performance of the Large Hadron Collider (LHC). In order to measure this parameter, the LHC transverse damper(ADT), used as an AC dipole, will provide the necessary beam excitation. The beam oscillations will be recorded by the Beam Positions Monitors and transmitted to dedicated analysis software. We set up the project with a 3-layer software architecture: The central part is a Java server, orchestrating the different actors: The Graphical User Interface, the control and triggering of the ADT AC dipole, the BPMs, the oscillation analysis (partly in Python), and finally the transmission of the correction values. The whole system was developed in a team using Scrum, an iterative and incremental agile software development framework. In this paper we present an overview of this system, experience from machine development and commissioning as well as how scrum helped us to achieve our goals. Improvement and re-use of the architecture with a nice decoupling between data acquisition and data analysis are also briefly discussed

    A single-administration therapeutic interfering particle reduces SARS-CoV-2 viral shedding and pathogenesis in hamsters.

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    UNLABELLED: The high transmissibility of SARS-CoV-2 is a primary driver of the COVID-19 pandemic. While existing interventions prevent severe disease, they exhibit mixed efficacy in preventing transmission, presumably due to their limited antiviral effects in the respiratory mucosa, whereas interventions targeting the sites of viral replication might more effectively limit respiratory virus transmission. Recently, intranasally administered RNA-based therapeutic interfering particles (TIPs) were reported to suppress SARS-CoV-2 replication, exhibit a high barrier to resistance, and prevent serious disease in hamsters. Since TIPs intrinsically target the tissues with the highest viral replication burden (i.e., respiratory tissues for SARS-CoV-2), we tested the potential of TIP intervention to reduce SARS-CoV-2 shedding. Here, we report that a single, post-exposure TIP dose lowers SARS-CoV-2 nasal shedding and at 5 days post-infection infectious virus shed is below detection limits in 4 out of 5 infected animals. Furthermore, TIPs reduce shedding of Delta variant or WA-1 from infected to uninfected hamsters. Co-housed 'contact' animals exposed to infected, TIP-treated, animals exhibited significantly lower viral loads, reduced inflammatory cytokines, no severe lung pathology, and shortened shedding duration compared to animals co-housed with untreated infected animals. TIPs may represent an effective countermeasure to limit SARS-CoV-2 transmission. SIGNIFICANCE: COVID-19 vaccines are exceptionally effective in preventing severe disease and death, but they have mixed efficacy in preventing virus transmission, consistent with established literature that parenteral vaccines for other viruses fail to prevent mucosal virus shedding or transmission. Likewise, small-molecule antivirals, while effective in reducing viral-disease pathogenesis, also appear to have inconsistent efficacy in preventing respiratory virus transmission including for SARS-CoV-2. Recently, we reported the discovery of a single-administration antiviral Therapeutic Interfering Particle (TIP) against SARS-CoV-2 that prevents severe disease in hamsters and exhibits a high genetic barrier to the evolution of resistance. Here, we report that TIP intervention also reduces SARS-CoV-2 transmission between hamsters

    Online luminosity control and steering at the LHC

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    This contribution reviews the novel LHC luminosity control software stack. All luminosity-related manipulations and scans in the LHC interaction points are managed by the LHC luminosity server, which enforces concurrency correctness and transactionality. Operational features include luminosity optimization scans to find the head-on position, luminosity levelling, and the execution of arbitrary scan patterns defined by the LHC experiments in a domain specific language. The LHC luminosity server also provides full built-in simulation capabilities for testing and development without affecting the real hardware. The performance of the software in 2016 and 2017 LHC operation is discussed and plans for further upgrades are presented
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