This article reports world averages of measurements of
b
-hadron,
c
-hadron, and
τ
-lepton properties obtained by the Heavy Flavor Averaging Group using results available through summer 2016. For the ...averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters,
C
P
violation parameters, parameters of semileptonic decays, and Cabbibo–Kobayashi–Maskawa matrix elements.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The INFN-LASA laboratory (Milano, Italy) is involved in the High-Luminosity LHC program for the design, construction, and test of 54 superconducting high-order corrector magnets. One of the ...challenging project stages was the transition from the construction of laboratory prototypes to the series production, awarded to industries, with the demanding requirement of maintaining high-quality production standards. Common and custom quality assurance (QA) methods were adopted for the analysis of the electrical characteristics of the coils. This paper discusses in detail the principle of the methods, their expected sensitivity, and the final observed effectiveness on the 510 produced coils. In some cases, the methods led to early defect detection thus avoiding possible severe damages during the final cold test that have already occurred for a prototype magnet not subject to the QA procedures described in this paper.
In agreement with CERN the LASA laboratory of INFN (National Institute for Nuclear Physics) of Milan has carried out the industrial development of a novel type of magnet, for the High Order (HO) ...correctors of the High Luminosity - LHC (HL-LHC) project. These corrector magnets are based on a superferric design and will be installed in the new HL-LHC insertion regions for the ATLAS and CMS Experiments at CERN. These fifty-four correctors cover different harmonic order: from skew quadrupole up to dodecapole, and all assembled in six cold masses named Corrector Packages, a novelty for superferric in a collider. The first magnet batches have been already manufactured by industry and tested at LASA. Magnetic measurements have been performed at low current (at room temperature) as well as at operating current (4.2 K during cold tests at LASA). The measurements have been used as production monitoring and magnet acceptance. The measurement setup, based on a rotating coil system, is described including also the commissioning of the new PCB probe, supplied by CERN. To assess the suitability for collider operation the field multipoles and the transfer function for the various magnet types are reported in the paper. The results have been also compared to the 3-D model calculations.
INFN is developing at the LASA lab (Milano, Italy) the High Order (HO) corrector magnets for the High Luminosity-LHC (HL-LHC) project, which will equip the new interaction regions. All the HO ...correctors, from skew quadrupole to dodecapole, are based on a novel superferric design, never used so far in high energy colliders, which allows a relatively simple, modular, and easy way to construct a magnet. The series production is ongoing after the completion of the five prototypes program; all the 54 series magnets have been produced in the industry and the testing at LASA is ongoing. The delivery to CERN also started. We discuss the design optimizations introduced and the lessons learned during the first half of the series production. We also focus on the quality assurance plan, which allowed us to early detect non-conformities and monitor the learning curve. The testing station at LASA is fully operational, four magnets per cool down are tested. Each magnet is powered individually, and the magnetic measurement system, supplied by CERN, provides field quality and transfer function. We provide an overview of the performed tests and measurements, focusing on the test station's performance and quality of the measurements. Finally, we provide an outlook of the production completion, test plan and delivery to CERN.
INFN has developed at the LASA lab (Milano, Italy) the High Order (HO) corrector magnets for the High Luminosity-LHC (HL-LHC) project, which will equip the new interaction regions. All the HO ...correctors, from skew quadrupole to dodecapole, are based on a novel superferric design, never used so far in high energy colliders, which allows a relatively simple, modular, and easy way to construct a magnet. After the completion of the production of the 54 series magnets in industry, the powering of all the produced magnets has been achieved. The delivery to CERN and the assembly of the first cold mass started. Each magnet has been powered individually and most of them have also been magnetically characterized, the aggregate results are presented and discussed. The lessons learned during the production and the testing of the magnets are reported. The quality assurance and the procedures developed in during development and production in industry proved to be key points of the successful experience of the HO correctors development, together with the solid design. We also report the lessons learned during the experience of the series production of the HO correctors.
In the family of the High-Luminosity LHC high order correctors, the skew quadrupole was the most critical magnet as three assemblies with different solutions were needed to meet the design ...specifications. This paper summarizes the prototyping phase of the magnet, discussing the observed nonconformities, the subsequent root cause analyses, and the adopted solutions. A first-hand experience showed us the importance of adopting rigorous quality assurance methods for the electrical insulation, aimed at the early defect detection, and implementing a consistent measurement-to-simulations chain for the optimization of the coils mechanical support. The improvements discussed in the paper are integrated into the final magnet design for the series production of six skew quadrupole correctors.
CERN and INFN, Italy, have signed an agreement for R&D activities relating to high-luminosity LHC superconducting magnets, which include the design, construction, and cryogenic test of a set of five ...prototypes, one for each type foreseen, from the skew quadrupole to the dodecapole. The reference layout of these magnets is based on a superferric design type, which allows reaching the required integrated field strength with a relatively simple design. Since the number of magnets of all the types required for the series is 36, emphasis has been put on modularity, reliability, ease of construction, and on the use of an available superconducting wire. This paper presents the status of the development work being performed at INFN, LASA Laboratory, and at CERN, focusing on the following issues: the electromagnetic 2- and 3-D design including harmonic component study; the fringe field analysis; the magnet powering and quench protection; mechanical and construction main choices.
Diffuse thrombosis represents one of the most predominant causes of death by COVID-19 and SARS-CoV-2 infection seems to increase the risk of developing venous thromboembolic diseases (VTE). Aim of ...this study is to analyze the relationship between validated predictive scores for VTE such as IMPROVE and IMPROVEDD and: (1) Intensification of Care (IoC, admission to Pulmonology Department or Intensive Care Unit) (2) in-hospital mortality rate 3) 30-days mortality rate.
We retrospectively evaluated 51 adult patients with laboratory diagnosis of SARS-CoV-2 infection and calculated IMPROVE and IMPROVEDD scores. All patients underwent venous color-Doppler ultrasound of the lower limbs to assess the presence of superficial vein thrombosis (SVT) and/or deep vein thrombosis (DVT). Patients with normal values of D-dimer did not receive heparin therapy (LMWH); patients with ≥ 4 ULN values of D-dimer or with a diagnosis of DVT were treated with therapeutic LMWH dosage, while the remaining patients were treated with prophylactic LMWH dosages.
We found strong relations between IMPROVE score and the need for IoC and with the in-hospital mortality rate and between the IMPROVEDD score and the need for IoC. We defined that an IMPROVE score greater than 4 points was significantly associated to in-hospital mortality rate (p = 0.05), while an IMPROVEDD score greater than 3 points was associated with the need for IoC (p = 0.04). Multivariate logistic analysis showed how IMPROVE score was significantly associated to in-hospital and 30-days mortality rates.
IMPROVE score can be considered an independent predictor of in-hospital and 30-days mortality.
High-power Hall Effect thrusters (HETs) represent an attractive propulsion option for the next-generation manned and robotic missions. The main challenging feature of these missions is a lifetime in ...the order of 104 hours required to the propulsion system. One of the most critical components of a HET is the cathode, used to emit electrons to sustain the discharge and to neutralize the ion beam. The main life-limiting factor of hollow cathodes designed for HETs is the material wear due to ion bombardment by the discharge plasma. The aim of this paper is to present the characterization of the electrical parameters and plasma plume properties of a hollow cathode. The effect of the cathode orifice geometry was also investigated, in terms of different length-to-diameter aspect-ratio (AR). Two ARs were analyzed to assess the effect of the orifice geometry on the plasma parameters and onset of unstable modes. The cathode analyzed, named HC20, is a hollow cathode developed for a mid-range power HET under development at SITAEL. The cathode was designed to provide discharge currents between 5 and 30 A, already characterized during previous experimental campaigns. The measurements in the plasma plume of the cathode were performed with triple Langmuir probes, one of which capable of scanning the plume along the cathode axis. The results show that a larger orifice AR can shift the transition to an unstable mode of operation of the cathode, named plume mode, at lower mass flow rate, increasing the cathode operative range.
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