Effective evaluation of the exact relativistic plasma dispersion functions

A new effective evaluation method of the exact relativistic plasma dispersion functions in the real and complex regions is given on the basis of nonsingular forms of Cauchy or Cauchy-type integrals and the Euler-Maclaurin formula.Предлагается новый эффективный метод вычисления точных релятивистских плазменных дисперсионных функций в реальной и комплексной областях на основе интегральных форм Коши или типа Коши и формулы Эйлера-Маклорена.Пропонується новий ефективний метод обчислення точних релятивістських плазмових дисперсійних функцій в реальній та комплексній областях на основі інтегральних форм Коші або типу Коші та формули Ейлера-Маклорена

Computation of the weakly relativistic plasma dispersion functions using superasymptotic and hyperasymptotic expansions

A new method to compute the weakly relativistic plasma dispersion functions for complex argument is presented. It is demonstrated that Jacobi fractions represent those functions asymptotically for z→ ∞ in the upper semi-plane.Предлагается новый метод вычисления слаборелятивистских плазменных дисперсионных функций комплексного аргумента.Пропонується новий метод обчислення слабкорелятивістських плазмових дисперсійних функцій комплексного аргументу

Electron Bernstein waves emission in the TJ-II Stellarator

Taking advantage of the electron Bernstein waves heating (EBWH) system of the TJ-II stellarator, an electron Bernstein emission (EBE) diagnostic was installed. Its purpose is to investigate the B-X-O radiation properties in the zone where optimum theoretical EBW coupling is predicted. An internal movable mirror shared by both systems allows us to collect the EBE radiation along the same line of sight that is used for EBW heating. The theoretical EBE has been calculated for different orientations of the internal mirror using the TRUBA code as ray tracer. A comparison with experimental data obtained in NBI discharges is carried out. The results provide a valuable information regarding the experimental O-X mode conversion window expected in the EBW heating experiments. Furthermore, the characterization of the radiation polarization shows evidence of the underlying B-X-O conversion process.Comment: 21 pages, 14 figure

Fast computation of the exact plasma dispersion functions

The paper is concerned with a computation of the exact relativistic plasma dispersion functions for complex argument z = x + iy in the region Q : y ≥ 0 on the base the theory of the continued fractions of Jacobi. It is first observed that these fractions represent those functions asymptotically for z → ∞ in the sector Q.На основі теорії ланцюгових дробів розвивається метод швидкого обчислення точних релятивістських плазмових дисперсійних функцій у комплексній області.На основе теории цепных дробей развивается метод быстрого вычисления точных релятивистских плазменных дисперсионных функций в комплексной области

Cs-induced charge transfer on (2x4)-GaAs(001) studied by photoemission

Cesium adsorption on 2x4 GaAs (001) was studied by photoemission and low energy electron diffraction. The different Cs induced changes of the As 3d and Ga 3d core level spectra show that charge transfer is almost complete for Ga surface sites, but is negligible to surface As at a coverage smaller than 0.3 ML. The situation is opposite for a coverage larger than 0.3ML, at which transfer occurs to As but no longer to Ga. Charge transfer to As atoms leads to disordering and destabilization and induces surface conversion from the As-rich surface to the Ga-rich 4x2 one after annealing at a reduced temperature of 450 C

Quality Assurance on a custom SiPMs array for the Mu2e experiment

The Mu2e experiment at Fermilab will search for the coherent $\mu \to e$ conversion on aluminum atoms. The detector system consists of a straw tube tracker and a crystal calorimeter. A pre-production of 150 Silicon Photomultiplier arrays for the Mu2e calorimeter has been procured. A detailed quality assur- ance has been carried out on each SiPM for the determination of its own operation voltage, gain, dark current and PDE. The measurement of the mean-time-to-failure for a small random sample of the pro-production group has been also completed as well as the determination of the dark current increase as a function of the ioninizing and non-ioninizing dose.Comment: 4 pages, 10 figures, conference proceeding for NSS-MIC 201

Design, status and perspective of the Mu2e crystal calorimeter

The Mu2e experiment at Fermilab will search for the charged lepton flavor violating process of neutrino-less $\mu \to e$ coherent conversion in the field of an aluminum nucleus. Mu2e will reach a single event sensitivity of about $2.5\cdot 10^{-17}$ that corresponds to four orders of magnitude improvements with respect to the current best limit. The detector system consists of a straw tube tracker and a crystal calorimeter made of undoped CsI coupled with Silicon Photomultipliers. The calorimeter was designed to be operable in a harsh environment where about 10 krad/year will be delivered in the hottest region and work in presence of 1 T magnetic field. The calorimeter role is to perform $\mu$/e separation to suppress cosmic muons mimiking the signal, while providing a high level trigger and a seeding the track search in the tracker. In this paper we present the calorimeter design and the latest R$\&$D results.Comment: 4 pages, conference proceeding for a presentation held at TIPP'2017. To be published on Springer Proceedings in Physic

The Mu2e undoped CsI crystal calorimeter

The Mu2e experiment at Fermilab will search for Charged Lepton Flavor Violating conversion of a muon to an electron in an atomic field. The Mu2e detector is composed of a tracker, an electromagnetic calorimeter and an external system, surrounding the solenoid, to veto cosmic rays. The calorimeter plays an important role to provide: a) excellent particle identification capabilities; b) a fast trigger filter; c) an easier tracker track reconstruction. Two disks, located downstream of the tracker, contain 674 pure CsI crystals each. Each crystal is read out by two arrays of UV-extended SiPMs. The choice of the crystals and SiPMs has been finalized after a thorough test campaign. A first small scale prototype consisting of 51 crystals and 102 SiPM arrays has been exposed to an electron beam at the BTF (Beam Test Facility) in Frascati. Although the readout electronics were not the final, results show that the current design is able to meet the timing and energy resolution required by the Mu2e experiment.Comment: 6 pages, 8 figures, proceedings of the "Calorimetry for the high energy frontier (CHEF17)" conference, 2-6 October 2017, Lyon, Franc

Бесконтактный температурный метод влияния поля при магнитотерапии

Запропоновано безконтактний температурний метод контролю впливу магнітного поля на біологічний об’єкт, який полягає в дистанційній реєстрації, візуалізації та аналізі теплових полів біологічних об’єктів в зоні дії індукторів на основі їх інфрачервоного випромінювання, та спосіб контролю впливу на організм магнітним полем, оснований на вимірюванні температури до, під час та по закінченню терапевтичної процедури. Проведене математичне моделювання впливу магнітного поля на зміну температури поверхневих шарів епідермісу та експериментальне дослідження зміни температури на індукторах магнітотерапевтичних апаратів «МАГ-30-4», «МИТ-11» та «ПОЛЮС-4» при їх контакті та без контакту з біологічним об’єктом.Are offered a contactless temperature quality monitoring of influence magnetic field on biological objects which consists in distant registration, visualisation that the analysis of thermal fields biological objects in the zone of action inductors on the basis of their caloric radiation, and a way of influence on an organism a magnetic field which based that the temperature to, in a time and on the termination of therapeutic procedure is measured. Mathematical modelling of influence of a magnetic field on change of temperature of superficial spheres epidermis and an experimental research of change of temperature on inductors magnetictherapy apparatuses «MAG-30-4», «MIT-11» and «POLUS-4» is spent at their contact and without contact to biological installation.Предложены бесконтактный температурный метод контроля влияния поля при магнитотерапии, который состоит в дистанционной регистрации, визуализации и анализе тепловых полей биологических объектов в зоне индукторов на основе их инфракрасного излучения, и способ контроля влияния на организм магнитным полем, основанный на измерении температуры до, во время и по окончанию терапевтической процедуры. Проведено математическое моделирование влияния магнитного поля на изменение температуры поверхностных шаров эпидермиса и экспериментальное исследование изменения температуры на индукторах магнитотерапевтических аппаратов «МАГ-30-4», «МИТ-11» и «ПОЛЮС-4» при их контакте и без контакта с биологическим объектом