Probability of radiation of twisted photons by classical currents

The general formula for the probability of radiation of a twisted photon by a classical current is derived. The general theory of generation of twisted photons by undulators is developed. It is proved that the probability to record a twisted photon produced by a classical current is equal to the average number of twisted photons in a given state. The general formula for the projection of the total angular momentum of twisted photons with given the energy, the longitudinal projection of momentum, and the helicity is obtained. The symmetry property of the average number of twisted photons produced by a charged particle moving along a planar trajectory is found. The explicit formulas for the average number of twisted photons generated by undulators both in the dipole and wiggler regimes are obtained. It is established that, for the forward radiation of an ideal right-handed helical undulator, the harmonic number $n$ of the twisted photon coincides with its projection of the total angular momentum $m$. As for the ideal left-handed helical undulator, we obtain that $m=-n$. It is found that the forward radiation of twisted photons by a planar undulator obeys the selection rule that $n+m$ is an even number. It turns out that the average number of twisted photons produced by the undulator and detected off the undulator axis is a periodic function of $m$ in a certain spectral band of the quantum numbers $m$.Comment: 36 pp; some misprints corrected; formulas (48)-(51) change

Properties of an ultrarelativistic charged particle radiation in a constant homogeneous crossed electromagnetic field

The properties of radiation created by a classical ultrarelativistic scalar charged particle in a constant homogeneous crossed electromagnetic field are described both analytically and numerically with radiation reaction taken into account in the form of the Landau-Lifshitz equation. The total radiation naturally falls into two parts: the radiation formed at the entrance point of a particle into the crossed field (the synchrotron entrance radiation), and the radiation coming from the late-time asymptotics of a particle motion (the de-excited radiation). The synchrotron entrance radiation resembles, although does not coincide with, the ultrarelativistic limit of the synchrotron radiation: its distribution over energies and angles possesses almost the same properties. The de-excited radiation is soft, not concentrated in the plane of motion of a charged particle, and almost completely circularly polarized. The photon energy delivering the maximum to its spectral angular distribution decreases with increasing the initial energy of a charged particle, while the maximum value of this distribution remains the same at the fixed observation angle. The ultraviolet and infrared asymptotics of the total radiation are also described.Comment: 14 pp, 3 fig

Neural network modeling of Herglotz—Wiechert inversion of multiparametric travel-time curves of seismic waves

Using artificial neural networks to solve a problem of plotting travel-time curves of seismic waves can create nonlinear travel-time model of P and S phases of seismic waves arrangement as a function of several arguments: source depth, magnitude, back azimuth and epicenter distance. Construction of three-dimensional travel-time relationships and their use for modeling of hadographs and their inversion are considered on examples of seismic records Ukrainian seismic stations. Examples of inversion locus within the model Herglotz—Wiechert and features of application of the model in a real environment for single seismic stations, and generalization for arbitrary coordinate of the source and the point of signal registration in the Black Sea region are given.Використання мереж штучних нейронів у задачі побудови годографів сейсмічних хвиль дає змогу створювати нелінійні моделі поля часів поширення P- і S-фаз сейсмічних хвиль як функцій декількох аргументів: глибини розміщення вогнища, магнітуди, азимуту надходження хвиль і епіцентральної відстані. Побудову тривимірних годографів розглянуто на прикладах сейсмічних записів українських сейсмостанцій і їх використання для моделювання годографів та інверсії останніх. Наведено приклади інверсії годографа в рамках моделі Герглотца— Віхерта, а також особливості застосування моделі в реальному середовищі для одиничних сейсмостанцій і узагальнення для випадку довільних координат джерела і точки реєстрації сигналу в Чорноморському регіоні

INFLUENCE OF OXYGENATOR EXTRACORPORAL CIRCUIT TREATMENT WITH ADAPTATION COMPOSITION (AdC) ON MORPHOLOGICAL CHANGES OF ERYTHROCYTES.

Summary. The study highlights a method of treatment extracorporeal circuit with «adaptation composition» (AdC) for the reduction of negative impact on state of erythrocytes. Materials and methods. A total of 90 patients were enrolled, they were divided into two groups. The group 1 (45 patients, 39/6 male/female) included patients who underwent surgical procedures without treatment of an extracorporeal circuit with AdC. The group 2 (45 patients, 39/6 male/female) included patients who underwent surgery with the treatment of an extracorporeal circuit with AdC. According to the study protocol, patient blood was sampling for complete blood cell count (CBC) and erythrocyte morphology at 4 stages of surgery: before surgery, at 10 min. CPB-time, at 60 min. CPB-time and after separation from CPB. Results. The albumin of AdC creates a protective nanolayer on the surface of the oxygenator membrane and tubes. There were no statistically significant differences of parameters in the groups before CPB. Level of Ht 2 (group 2) at 60 min CPB-time and after CPB, were lower than Ht 1 (group 1) (p=0.021 and p=0.035 correspondingly) because MCV1 was higher (р=0.025 and p<0.0001 correspondingly). The increase MCHC in groups at 10 min. CPB-time relatives with the decrease in MCV at 10 min CPB-time. At 60 min, there are changes of RDWa2 76.05 ± 5.46 and RDWa1 72.35 ± 7.26, p<0.000. After CPB higher content of reticulocytes (р <0.0001), echinocytes (р <0.0001) and spherocytes (р <0.0001) is observed in group 1. The lowering of mechanical resistance (р = 0.04) and increasing membrane permeability for urea were in group 1. After CPB the best aсid hemolysis resistance was in group 2 (р = 0.05), erythrocytes were more resistant to hypoosmotic factor (р = 0.01) in group 2. Conclusion. The treatment of oxygenator with AdC reduces the negative influence СРВ on state of RBC. Membranes of erythrocytes were more resistant to traumatic factors in the group with AdC.В роботі висвітлюється метод обробки экстракорпорального контура оксигенатора «адаптуючою композицією» (adaptation composition – AdC) для зменшення негативного впливу штучного кровообігу на стан еритроцитів. Матеріали і методи. В дослідження було включено 90 пациентов, які були розподілені на дві групи. Пацієнтам першої групи (45 хворих, 39/6 чол./жін.) оперативні втручання виконували без обробки контуру оксигенатору адаптуючою композицією (AdC). Оперативні втручання у пацієнтів другої групи (45 пацієнтів - 36/9 чол./жін.) проводились з обробкою AdC. Згідно протоколу дослідження, у пацієнтів набирали кров для загального аналізу крові та морфологічного дослідження еритроцитів на 4 етапах оперативного втручання: до початку операції, на 10 хв. ШК, на 60 хв. ШК та в кінці операції. Результати та їх обговорення. Альбумін в складі AdС створює наношар на поверхні магистралей та мембрани оксигенатора. Між групами до ШК не було статистично значущої різниці у показниках. Рівень Ht 2 (група 2) на 60 хв. ШК ти після ШК був нижче, ніж Ht 1 (група 1) (p=0,021 і p=0,035 відповідно) через зібльшення MCV 1 (р=0,025 і p <0,0001 відповідно). На 10 хв. ШК підвищення МСНС в групах пов'язано зі зниженням MCV на 10 хв. ШК. На 60 хв. від початку ШК відбувається зміна в RDWа2 76,05 ± 5,46 і RDWа1 72,35 ± 7,26, р <0,0001. Після ШК в групі 1 визначається більш високий вміст ретикулоцитів (р <0,0001), ехіноцитів (р <0,0001) і сфероцитів (р <0,0001). В групі 1 після ШК відбувається зниження механічної стійкості еритроцитів (р = 0,04) та підвищена проникність мембрани еритроцитів для сечовини. Після ШК більша резистентність еритроцитів до кислотного гемолізу була в групі 2 (р = 0,05), також в групі 2 еритроцити були більш стійкими до гіпоосмотичному фактору (р = 0,01). Висновки. Обробка оксигенатора адаптуючою композицією призводить до зменшення негативного впливу ШК на стан еритроцитів. Мембрани еритроцитів були більш резистентні до дії факторів що ушкоджують в групі з використанням AdC

Translation peculiarities of idioms: cultural aspect, metaphorical grounds

Idioms are found in every language and learning them is an important aspect of mastering a language. The English language is no exception as it contains a large number of idioms, which are extensively used. Due to their rigid structure and quite unpredictable meaning, idioms are often considered difficult to learnyesBelgorod State Universit

Методологія природознавства як засіб формування в учнів сучасної фізичної картини світу

Метою є обгрунтувати логіку проектування та розробити методику реалізації світоглядних ситуацій на уроках фізики основної школи з позицій діяльнісного та особистісного підходів.The aim is to justify the logic proection and develop a methodology for implementation of ideological situations at primary school physics lessons from the standpoint of activity and personal approach

Transition radiation from a Dirac particle wave packet traversing a mirror

The explicit expression for the inclusive probability to record a photon created in transition radiation from a one Dirac particle wave packet traversing an ideally conducting plate is derived in the leading order of perturbation theory. The anomalous magnetic moment of the Dirac particle is taken into account. It is shown that the quantum corrections to transition radiation from an electrically charged particle give rise to production of photons with polarization vector orthogonal to the reaction plane ($E$-plane). These corrections result from both the quantum recoil and the finite size of a wave packet. As for transition radiation produced by a neutron falling normally onto the conducting plate, the probability to detect a photon with polarization vector lying in the reaction plane does not depend on the observation angle and the energy of the incident particle. The peculiarities of transition radiation stemming from different shapes of the particle wave packet are investigated. In particular, the transition radiation produced by the wave packet of one twisted Dirac particle is described. The comparison with classical approach to transition radiation is given and the quantum formula for the inclusive probability to detect a photon radiated by the $N$-particle wave packet is derived.Comment: 21 pp; some misprints correcte

Semiclassical probability of radiation of twisted photons in the ultrarelativistic limit

The semiclassical general formula for the probability of radiation of twisted photons by ultrarelativistic scalar and Dirac particles moving in the electromagnetic field of a general form is derived. This formula is the analog of the Baier-Katkov formula for the probability of radiation of one plane wave photon with the quantum recoil taken into account. The derived formula is used to describe the radiation of twisted photons by charged particles in undulators and laser waves. Thus, the general theory of undulator radiation of twisted photons and radiation of twisted photons in the nonlinear Compton process is developed with account for the quantum recoil. The explicit formulas for the probability to record a twisted photon are obtained in these cases. In particular, we found that the quantum recoil and spin degrees of freedom increase the radiation probability of twisted photons in comparison with the formula for scalar particles without recoil. In the range of applicability of the semiclassical formula, the selection rules for undulator radiation established in the purely classical framework are not violated. The manifestation of the blossoming out rose effect in the nonlinear Compton process in a strong laser wave with circular polarization and in the wiggler radiation is revealed. Several examples are studied: the radiation of mega-electron-volt twisted photons by 180 GeV electrons in the wiggler, the radiation of twisted photons by 256 MeV electrons in strong electromagnetic waves produced by the CO2 and Ti:Sa lasers, and the radiation of MeV twisted photons by 51.1 MeV electrons in the electromagnetic wave generated by the free-electron laser with photon energy 1 keV