A Quench Detection and Monitoring System for Superconducting Magnets at Fermilab

A quench detection system was developed for protecting and monitoring the superconducting solenoids for the Muon-to-Electron Conversion Experiment (Mu2e) at Fermilab. The quench system was designed for a high level of dependability and long-term continuous operation. It is based on three tiers: Tier-I, FPGA-based Digital Quench Detection (DQD); Tier-II, Analog Quench Detection (AQD); and Tier-3, the quench controls and data management system. The Tier-I and Tier-II are completely independent and fully redundant systems. The Tier-3 system is based on National Instruments (NI) C-RIO and provides the user interface for quench controls and data management. It is independent from Tiers I & II. The DQD provides both quench detection and quench characterization (monitoring) capability. Both DQD and AQD have built-in high voltage isolation and user programmable gains and attenuations. The DQD and AQD also includes user configured current dependent thresholding and validation times. A 1st article of the three-tier system was fully implemented on the new Fermilab magnet test stand for the HL-LHC Accelerator Up-grade Project (AUP). It successfully provided quench protection and monitoring (QPM) for a cold superconducting bus test in November 2020. The Mu2e quench detection design has since been implemented for production testing of the AUP magnets. A detailed description of the system along with results from the AUP superconducting bus test will be presented

Anodal Block in Evaluation of Nerve Conduction Changes in Anesthetized Rats: Preclinical Non-Randomized Experimental Study

Background. There is currently no gold standard for functional assessment of nerve regeneration. Different researchers use various methods to assess the functionality of the regenerated nerve directly and indirectly. Indirect methods have the advantage of being minimally invasive, and the benefit of direct methods is recording the signal directly in the nerve.Objectives. To identify significant parameters of neurogram changes in the sciatic nerve in an anaesthetized rat when the anode block is applied and to evaluate neurography as a method for functional assessment of nerve regeneration.Methods. A series of experiments was performed on 10 anaesthetized rats. A DC anode was placed on the exposed sciatic nerve, more proximal and more distal to the recording electrodes, and a common cathode in the form of a needle was introduced into one of the forelimbs. Needle nichrome electrodes were introduced into the nerve using a manipulator. An original neurogram and a neurogram against anode activation were recorded by closing the DC circuit of different voltages to block the afferent signal, efferent signal and afferent and efferent signals simultaneously.Results. When the anodal block of different voltages was applied to the afferent signal, efferent signal, and afferent and efferent signals simultaneously in all 10 experiments, the frequency-amplitude characteristics of the neurogram changed significantly as compared to the original neurogram. The amplitude of the neurogram increased considerably, while the frequency decreased, though not so dramatically. The changes in amplitude and frequency parameters were revealed to depend on the voltage value. In most cases, this relationship was directly proportional to the amplitude and inversely proportional to the frequency.Conclusion. Considering the nature of the dynamics of the neurogram when exposed to the anodal block, the most significant parameter of its change is the amplitude. Changes in nerve fibre composition during its regeneration after damage cause changes in afferent and efferent signals, which is likely to be displayed in the neurogram as compared to the initial state. Thus, the anodal block can be used as a model of nerve damage, and the analysis of the dynamics of neurogram parameters — as a method for functional assessment of nerve regeneration

Hermeian haloes: Field haloes that interacted with both the Milky Way and M31

The Local Group is a unique environment in which to study the astrophysics of galaxy formation. The proximity of the Milky Way and M31 enhances the frequency of interactions of the low-mass halo population with more massive dark matter haloes, which increases their concentrations and strips them of gas and other material. Some low-mass haloes pass through the haloes of the Milky Way or M31 and are either ejected into the field or exchanged between the two primary hosts. We use high resolution gas-dynamical simulations to describe a new class of field haloes that passed through the haloes of both the Milky Way and M31 at early times and are almost twice as concentrated as field haloes that do not interact with the primary pair. These 'Hermeian' haloes are distributed anisotropically at larger distances from the Local Group barycentre than the primary haloes and appear to cluster along the line connecting the Milky Way and M31. Hermeian haloes facilitate the exchange of dark matter, gas, and stars between the Milky Way and M31 and can enhance the star formation rates of the gas in the primary haloes during their interactions with them. We also show that some Hermeian haloes can host galaxies that, because they are embedded in haloes that are more concentrated than regular field haloes, are promising targets for indirect dark matter searches beyond the Milky Way virial radius and can produce signals that are competitive with those of some dwarf galaxies. Hermeian galaxies in the Local Group should be detectable by forthcoming wide-field imaging surveys

СИНТЕЗ СИСТЕМЫ ЗАЖИГАНИЯ АВТОМОБИЛЯ, РАБОТАЮЩЕГО НА ОЗОНИРОВАННОМ ТОПЛИВЕ

The paper presents a mathematical model for electronic control system of the angular ignition timing (AIT) in the (ICE), which is running on ozonized fuel. An algorithm for  ignition system control of internal combustion engine using ozonized fuel has been developed in the paper. A structure of the dynamic ignition system while using a control unit for supplying  ozone into fuel with a purpose to improve automobile ecological and economical indices adapted to operational conditions. Application of the given system allows to ensure minimum reduction of operational petrol consumption and concentration of incomplete combustion products due to optimum ozone dosage into the fuel.  The paper proposes a controlled automobile ignition system as a sequential scheme which has a great number of discrete inputs and outputs and many discrete internal  states. The scheme establishes a functional dependence between input and output states. The paper provides an assessment of ecological indices according to massive emissions of carbon monoxide СО, hydrocarbon СпНт and nitric oxide NOx .  The analysis of  investigations results has been carried out in the paper.Разработана математическая модель электронной системы управления углом опережения зажигания (УОЗ) в двигателе внутреннего сгорания (ДВС), работающем на озонированном топливе. Разработан алгоритм управления системой зажигания ДВС на озонируемом топливе. Создана структура динамической системы зажигания с использованием блока управления подачи озона в топливо для повышения экологических и экономических показателей автомобиля адаптированных к условиям эксплуатации. Применение данной системы позволяет за счет дозирования оптимального количества озона в топливо обеспечить снижение расхода бензина и концентрации продуктов неполного сгорания с точки зрения минимумов в условиях эксплуатации. Представлена управляемую систему зажигания автомобиля как последовательную схему, которая имеет множество дискретных входов, множество дискретных выходов и множество дискретных внутренних состояний. Схема устанавливает функциональную зависимость между состояниями входа и состояниями выхода. Проведена оценка экологических показателей по массовым выбросам оксида углерода СО углеводородов СпНт, оксидов азота NOx, выполнен анализ результатов исследований

Measurement of the atmospheric muon charge ratio with the OPERA detector

The OPERA detector at the Gran Sasso underground laboratory (LNGS) was used to measure the atmospheric muon charge ratio in the TeV energy region. We analyzed 403069 atmospheric muons corresponding to 113.4 days of livetime during the 2008 CNGS run. We computed separately the muon charge ratio for single and for multiple muon events in order to select different energy regions of the primary cosmic ray spectrum and to test the charge ratio dependence on the primary composition. The measured charge ratio values were corrected taking into account the charge-misidentification errors. Data have also been grouped in five bins of the "vertical surface energy". A fit to a simplified model of muon production in the atmosphere allowed the determination of the pion and kaon charge ratios weighted by the cosmic ray energy spectrum.Comment: 14 pages, 10 figure

Emulsion sheet doublets as interface trackers for the OPERA experiment

New methods for efficient and unambiguous interconnection between electronic counters and target units based on nuclear photographic emulsion films have been developed. The application to the OPERA experiment, that aims at detecting oscillations between mu neutrino and tau neutrino in the CNGS neutrino beam, is reported in this paper. In order to reduce background due to latent tracks collected before installation in the detector, on-site large-scale treatments of the emulsions ("refreshing") have been applied. Changeable Sheet (CSd) packages, each made of a doublet of emulsion films, have been designed, assembled and coupled to the OPERA target units ("ECC bricks"). A device has been built to print X-ray spots for accurate interconnection both within the CSd and between the CSd and the related ECC brick. Sample emulsion films have been extensively scanned with state-of-the-art automated optical microscopes. Efficient track-matching and powerful background rejection have been achieved in tests with electronically tagged penetrating muons. Further improvement of in-doublet film alignment was obtained by matching the pattern of low-energy electron tracks. The commissioning of the overall OPERA alignment procedure is in progress.Comment: 19 pages, 19 figure