Accelerator performance analysis of the Fermilab Muon Campus

Fermilab is dedicated to hosting world-class experiments in search of new physics that will operate in the coming years. The Muon g-2 Experiment is one such experiment that will determine with unprecedented precision the muon anomalous magnetic moment, which offers an important test of the Standard Model. We describe in this study the accelerator facility that will deliver a muon beam to this experiment. We first present the lattice design that allows for efficient capture, transport, and delivery of polarized muon beams. We then numerically examine its performance by simulating pion production in the target, muon collection by the downstream beam line optics, as well as transport of muon polarization. We finally establish the conditions required for the safe removal of unwanted secondary particles that minimizes contamination of the final beam.Comment: 10 p

Multi-wavelength thermal-lens spectrometry for high-accuracy measurements of absorptivities and quantum yields of photodegradation of a hemoprotein–lipid complex

AbstractAccurate measurements of absorptivities and quantum yields of biochemical species under various conditions are an important task of applied photonics and analytical chemistry. In this work, we provide a comparison of the capabilities of thermal-lens spectrometry to measure these parameters of various samples. Measurements of relevant model substances, biologically active substituted 2-thiohydantoins and their complexes of copper(I,II) and heme proteins (forms of hemoglobin and cytochrome c), showed negligible differences in apparent molar absorptivities for thermal-lens spectrometry and optical-absorption (spectrophotometric) data. The values for tabletop and microscale thermal-lens measurements under batch conditions differ insignificantly. The precision of measurements of molar absorptivities by thermal-lens spectrometry is no less than in the case of spectrophotometry or the precision is even higher in the cases of low absorptivities. For cardiolipin–cytochrome c-NO complex, the difference between absorptivity values calculated from thermal-lens data and acquired by spectrophotometry is significant due to complex photodegradation. The quantum yield of its photolysis reaction calculated from optical absorption and thermal-lens data altogether at two wavelengths for 0.4–360s of the reaction, 0.46±0.04, was estimated

Особливості багатошарового наплавання з використанням модуляції параметрів дугового процесу

Особливості багатошарового наплавання з використанням модуляції параметрів дугового процесу = Characteristics of multi-layer deployment using modulation of arc process parameters / В. О. Лебедєв, В. О. Тищенко, В. В. Спіхтаренко, С. А. Лой // Shipbuilding & Marine Infrastructure. – 2022. – № 1 (16). – С. 15–23.Наплавлення застосовується в основному для відновлення вузлів, що вже перебували в експлуатації, і тим самим продовжують термін їх експлуатації. Серед способів наплавлення можна відзначити два основних напрямки, які реалізуються за рахунок імпульсних і модульованих алгоритмів впливу на дуговий процес. Це насамперед способи, що впливають роботу джерела зварювального струму з періодичною зміною вихідної напруги та системи подачі електродного дроту з можливістю управління струмом зварювання – наплавлення. Метою роботи є підвищення експлуатаційних характеристик наплавлення за рахунок реалізації імпульсних та модульованих методів на дуговий процес. У даній роботі наведено дослідження та аналіз характеристик металу в зоні між наплавленими валиками, а також у зоні багатошарового наплавлення з оцінкою їх впливу на експлуатаційні можливості вузлів та деталей при використанні наплавлення з модульованими режимами. Для проведення програми досліджень було обрано комплекс обладнання у складі автомата А-874Н з випрямлячем ВДУ-506. Модуляція параметрів режиму проводилася за допомогою дослідної приставки модулятора ОИ-10 – конструкції ІЕЗ ім. Є.О. Патона шляхом періодичної зміни частоти обертання валу приводного електродвигуна механізму подачі електродного дроту, або синхронізованого впливу на електричні ланцюги управління джерела живлення та електроприводу двигуна подачі електродного дроту. У модуляторі є два канали управління – для електроприводу механізму подачі електродного дроту, а також заданням рівнів максимальної та мінімальної вихідної напруги і максимальної та мінімальної частот обертання валу приводного електродвигуна і відповідно струму зварювання. Наплавлення дослідних зразків проводилося високолегованим порошковим самозахисним електродним дротом ПП-АН-140 діаметром 2,0 мм. Наплавлення виконували на стандартних зразках, виконаних з легованих конструкційних сталей, переважно матеріалів штампового інструменту. Наплавлений шар випробовувався на зносостійкість. Вивчалася мікротвердість та мікроструктура отриманого шару. Результати дослідження показали, що використання модульованого струму при наплавленні зносостійкого шару дозволяє збільшити показники зносостійкості, при цьому модуляція режимів дугового процесу дозволяє поліпшити показники зносостійкості, так і показники твердості.Surfacing is mainly used to restore units that have already been in operation and thereby extend their service life. Among the surfacing methods, two main directions can be noted, which are implemented due to pulsed and modulated algorithms for influencing the arc process. First of all, these are methods that affect the operation of the welding power source with a periodic change in the output voltage and the electrode wire supply system with the ability to control the welding current – surfacing. The purpose of the work is to improve the operational characteristics of surfacing through the implementation of pulsed and modulated methods of influencing the arc process. This paper presents studies and analysis of the characteristics of the metal in the zone between the deposited beads, as well as in the zone of multilayer surfacing with an assessment of their influence on the operational capabilities of units and parts when using surfacing with modulated modes. To carry out the research program, a set of equipment consisting of an A-874N automatic machine with a VDU-506 rectifier was chosen. The modulation of the mode parameters was carried out with the help of an experimental attachment modulator OI-10 – designed by the PWI. E.O. Paton by either periodically changing the rotational speed of the drive motor shaft of the electrode wire feed mechanism, or by synchronizing the effect on the electrical control circuits of the power source and the electric drive of the electrode wire feed motor. The modulator has two control channels – for the electric drive of the electrode wire feed mechanism, as well as for setting the levels of the maximum and minimum output voltage and the maximum and minimum speeds of the drive motor shaft and, accordingly, the welding current. Surfacing of prototypes was carried out with highly alloyed flux-cored self-shielding electrode wire PP-AN-140 with a diameter of 2.0 mm. Surfacing was performed on standard specimens made of tool steels, mainly from materials of stamping tools. The deposited layer was tested for wear resistance. The microhardness and microstructure of the obtained layer were studied. The results of the study showed that the use of modulated current when surfacing a wear-resistant layer makes it possible to increase the wear resistance indicators, while the modulation of the arc process modes improves both the wear resistance indicators and the hardness indicators

Seasonal hydrological and hydrochemical surveys in the Voevoda Bay (Amur Bay, Japan Sea)

Hydrological and hydrochemical surveys were conducted in the Voevoda Bay in May, August, and October, 2011 and February, 2012, in total 140 stations. Free water exchange of the bay with the Amur Bay is observed, with exception of its inner bights Kruglaya and Melkovodnaya. The water exchange is maintained by anticyclonic circulation with the inflow along the southern coast and outflow along the northern coast of the Voyevoda Bay. However, the opposite cyclonic circulation is observed in the Melkovodanaya Bight because of its coastal line patterns and fresh water discharge by the river. Dissolved oxygen content and partial pressure of CO2 in the bay waters are determined mostly by intensive processes of production and destruction of organic matter. There are three main groups of primary producers there, as diatom algae, sea grass Zostera marina , and periphyton. Specific chemical regime is formed in the Melkovodnaya Bight, in particular in winter when primary production depends on the ice cover and is driven by variations of photosynthetically active radiation passed through the ice. Seasonal variability of production-destruction processes intensity is discussed on the data of chemical parameters changes

Measurement of proton, deuteron, triton, and α particle emission after nuclear muon capture on Al, Si, and Ti with the AlCap experiment

Background: Heavy charged particles after nuclear muon capture are an important nuclear physics background to the muon-To-electron conversion experiments Mu2e and COMET, which will search for charged lepton flavor violation at an unprecedented level of sensitivity. Purpose: The AlCap experiment aimed to measure the yield and energy spectra of protons, deuterons, tritons, and α particles emitted after the nuclear capture of muons stopped in Al, Si, and Ti in the low-energy range relevant for the muon-To-electron conversion experiments. Methods: Individual charged particle types were identified in layered silicon detector packages and their initial energy distributions were unfolded from the observed energy spectra. Results: The proton yields per muon capture were determined as Yp(Al)=26.64(28stat.)(77syst.)×10-3 and Yp(Ti)=26.48(35)(80)×10-3 in the energy range 3.5-20.0 MeV, and as Yp(Si)=52.5(6)(18)×10-3 in the energy range 4.0-20.0 MeV. Detailed information on yields and energy spectra for all observed nuclei are presented in the paper. Conclusions: The yields in the candidate muon stopping targets, Al and Ti, are approximately half of that in Si, which was used in the past to estimate this background. The reduced background allows for less shielding and a better energy resolution in these experiments. It is anticipated that the comprehensive information presented in this paper will stimulate modern theoretical calculations of the rare process of muon capture with charged particle emission and inform the design of future muon-To-electron conversion experiments.</p

On the possibility for laboratory simulation of generation of Alfvén disturbances in magnetic tubes in the solar atmosphere

The paper deals with generation of Alfvén plasma disturbances in magnetic flux tubes through exploding laser plasma in magnetized background plasma. Processes with similar effect of excitation of torsion-type waves seem to provide energy transfer from the solar photosphere to the corona. The studies were carried out at experimental stand KI-1 representing a high-vacuum chamber 1.2 m in diameter, 5 m in length, external magnetic field up to 500 G along the chamber axis, and up to 2·10–6 Torr pressure in operating mode. Laser plasma was produced when focusing the CO2 laser pulse on a flat polyethylene target, and then the laser plasma propagated in θ-pinch background hydrogen (or helium) plasma. As a result, the magnetic flux tube 15–20 cm in radius was experimentally simulated along the chamber axis and the external magnetic field direction. Also, the plasma density distribution in the tube was measured. Alfvén wave propagation along the magnetic field was registered from disturbance of the magnetic field transverse component Bφ and field-aligned current Jz. The disturbances propagate at a near-Alfvén velocity 70–90 km/s and they are of left-hand circular polarization of the transverse component of magnetic field. Presumably, the Alfvén wave is generated by the magnetic laminar mechanism of collisionless interaction between laser plasma cloud and background. A right-hand polarized high-frequency whistler predictor was registered which propagated before the Alfvén wave at a velocity of 300 km/s. The polarization direction changed with the Alfvén wave coming. Features of a slow magnetosonic wave as a sudden change in background plasma concentration along with simultaneous displacement of the external magnetic field were found. The disturbance propagates at ~20–30 km/s velocity, which is close to that of ion sound at low plasma beta value. From preliminary estimates, the disturbance transfers about 10 % of the original energy of laser plasma.</jats:p

Microwave radiometry in monitoring and emergency mapping of water seepage and dangerously high groundwaters, Journal of Telecommunications and Information Technology, 2007, nr 1

Detailed and geo-referenced maps identifying the locations of saturated and dry levees can be produced using microwave radiometric measurements from a light aircraft or helicopter, and integrated with GPS for positioning and orientation. The development of synergetic remote sensing technology for raised groundwater and seepage detection by the joint use of microwave and optical data along with GIS databases is an effective and most contemporary way of supporting risk assessment and facilitating disaster prevention and management. In this paper we present a remote sensing microwave technology for monitoring and detection of areas of water seepage through irrigation constructions, levees and dykes as well as for revealing areas with dangerously high groundwater level. The possibility for emergency response mapping, integrated with GPS and GIS data, facilitates the risk assessment and management services. The passive microwave radiometry (PMR) is based on spectral measurements in the millimetre to decimetre range of wavelengths. Compared to other remote sensing techniques, such as colour and infrared photography, thermal images and lidar, PMR is the only technology taking measurements under the earth’s surface and therefore is very well suited for water seepage and underground water monitoring in a fast and reliable way

A correction of water balance in sport

It is presented an information about the state of water balance for the sportsmen of high qualification under act of the physical loadings. Directions of prophylaxis dehydration are considered. Basic aspects and methods are shown for conducting of the drinkable mode. The necessity of correction of water balance is grounded. It is set that at the aerobic loadings dehydration is reduced by a capacity on 20%. The most optimum variant of filling in of supplies of water is filling in with intensity of the proper intensity of its losses