Coordinatori
PS1 - Poster session
- Dariush Hampai (LNF)
Sig.
Aleksandr Savchenko
(NRNU MEPhI, Russia, Moscow)
24/09/18, 18:40
Poster
Backward transition radiation (BTR) is used at accelerators as a precise instrument for beam diagnostics. Being conventionally used in optical range, BTR based monitors are promising for submicron diagnostics, provided EUV and soft X-ray range is operated. Despite the theory of TR is very well developed, however, to the best of our knowledge the theory of backward TR from multilayered...
Prof.
Yuri Kunashenko
(National Research Tomsk Polytechnic University; Tomsk State Pedagogical University)
24/09/18, 18:40
Poster
In the present report on the base of solution Dirac equation [1] for axially channeled electron with fixed spin direction we find CR cross – section of twisted phonons (photons with fixed projection of angular momentum).
Dr.
Sergey Galyamin
(Saint Petersburg State University)
24/09/18, 18:40
Poster
We continue investigation of radiation produced by a charged particle bunch moving through the concentrator for Cherenkov radiation. We take into account a series of issues affecting the dimensions of the focal spot and distribution of the field across this area. It is reasonable to take into account finite length of the bunch and a small shift of the bunch from the axis. Moreover, it is...
Prof.
Yuri Kunashenko
(National Research Tomsk Polytechnic University; Tomsk State Pedagogical University)
24/09/18, 18:40
Poster
The solution of the Dirac equation for the electron (positron) in a continuous potential of the crystal axis taking into account the periodicity of the crystal in the direction of the axis was found in [1].
In a present report using those wave functions, we theoretical study the coherent bremsstrahlung from axially channeled electrons. Calculation shows that channeling of created particles...
192.
Coherent Radiation Characteristics of Modulated Positron Bunch, Formed in Crystalline Undulator
24/09/18, 18:40
Poster
The coherent X-ray radiation at a zero angle and at a resonant frequency, formed in crystalline undulator (CU) by the modulated positron bunch, is investigated. Taking into account the medium polarization, CU parameter and bunch energy are determined for both the conservation of channeling phenomenon and the photon beam with optimal characteristics. The spectrum of a coherent radiation has...
Dr.
Behnam Azadegan
(Hakim Sabzevari University, Physics department)
24/09/18, 18:40
Poster
At ion accelerators, the neutron yield is investigated in dd reactions within a TiD2 crystalline under irradiation by a deuterium ion beam with the energy of less than 30 keV [1-8]. To study such reaction with an ultralow collision energy, there is a need in the information on the yield of neutrons in the reaction d(d,n)3He versus the angular and spatial distribution of particles during the...
Sig.
Sergei Stuchebrov
(Tomsk Polytechnic University)
24/09/18, 18:40
Poster
This report demonstrates the results of experimental and theoretical studies of generation and transmission mechanisms of Cherenkov radiation in an optical fiber when an electron beam hits (or interacts with) a fiber. Measured dependence of a signal level of Cherenkov radiation transmitted through the fiber on value of incidence angle is presented. The experimental study has been carried out...
Sig.na
Alesia Leukovich
(INP BSU)
24/09/18, 18:40
Poster
We present the details of the modification of GEANT4 cross-sections for bremsstrahlung and electron-positron pair production in case of particle moving along the strongest PWO crystal axes. The scaling coefficients for cross-section modification depend on particle energy and have been previously calculated through the direct integration of Baier-Katkov formula. We used the modified GEANT4 to...
Sig.
Aleksandr Savchenko
(NRNU MEPhI, Russia, Moscow)
24/09/18, 18:40
Poster
We continue our investigation of the calorimeter system for the muon g-2 experiment. In our previous work we have shown the excellent spatial distribution of photons at the calorimeter crystals back surface, which is of a certain importance for the precise measurement of primary positron energy. We have also evaluated both photon energy and angular distributions as well as the time...
Dr.
Oleg Bogdanov
(LNF&TPU), Dr.
Peter Kazinski
(Tomsk State University)
24/09/18, 18:40
Poster
At the present moment, the bent crystals are employed as an effective tool for deflection of particle beams. There are also promising prospects for their use as alternative inexpensive sources of x-ray photons [1]. We develop this idea to apply the bent crystals for production of the so-called twisted photons, i.e., the photons with definite the energy, the longitudinal projection of momentum,...
Dr.
Timur Tukhfatullin
(National Research Tomsk Polytechnic University)
24/09/18, 18:40
Poster
The measurements of cross-sections of fusion reactions with ‘bare nuclei’ D(d, p)3H, D(d, n)3He, T(d, n)3He, 3He(d, p)4He, and D(3He, p)4He at astrophysical energies is of interest both for basic and applied physics [1]. These reactions participate in primordial nucleosynthesis. Information on the number of the D, T, 3He, and 4He nuclei formed in the early universe is used to characterize...
Dr.
Nikolai Maksyuta
(Taras Shevchenko National University of Kiev, Ukraine)
24/09/18, 18:40
Poster
This paper is a continuation of [1, 2]. In [1] at investigation of the channeling of relativistic electrons in ionic crystals it was shown that its electromagnetic field induces non-stationary dipole moments in a crystalline medium. This effect is the result of the inverse action of the field of channeled particle to crystal environment. From the other hand the arising non-stationary dipoles...
Sig.na
Xiatong Li
(Tomsk Polytechnic University)
24/09/18, 18:40
Poster
Sig.
Kirill Fedorov
(Royal Holloway, University of London)
24/09/18, 18:40
Poster
Producing and diagnostic of short bunches in modern particle accelerators are forefront issues. For example in modern high-gain free-electron lasers the electron bunches are longitudinally compressed down to 100 fs to achieve high peak currents which is crucial to drive FEL process. Such a short bunch duration opens the possibility to use effect of coherent radiation for longitudinal beam...
Dr.
Eugene Bulyak
(NSC KIPT)
24/09/18, 18:40
Poster
We report estimations on production of coherent photons in gamma region by relativistic electrons in periodic structures. Two aspects of coherency were considered: coherency of photons emitted by a single electron over the system, and coherency of the photons emitting by a bunch of electrons at a given position. The first aspect provides density of radiation in proportion to squared number of...
Prof.
Nikolai Shul'ga
(Akhiezer Institute for Theoretical Physics of NSC KIPT)
24/09/18, 18:40
Poster
When fast charged particles move in crystal at small angle to one of the crystalline planes their motion in the crystal can have both finite (planar channeling) and infinite (above-barrier) character relatively the crystalline planes. The problem of the motion of such particles in a crystalline undulator in which the crystalline planes are periodically deformed is of special interest. It is...
Dr.
Nikolai Maksyuta
(Taras Shevchenko National University of Kiev)
24/09/18, 18:40
Poster
This paper is a continuation of the work [1], in which was considered the possibility of generation of a short-wave radiation due to the pseudophotons fields use based on three-frequency parametric interaction on channeled electrons system in certain crystallographic directions of some crystals in which there are non-unimodal potential wells. For example, crystals with the structure of a zinc...
Dr.
Julia Janz
(Tomsk polytechnic university)
24/09/18, 18:40
Poster
The angular momentum of electromagnetic radiation has been widely studied in recent years. The first theoretical and experimental research have been made by use of laser radiation. Radiation in the x-ray range carrying the angular momentum was recently obtained by using a helical undulator at BESSY II storage ring. Some authors proposed the methods for generation radiation with angular...
Dr.
Nikolai Maksyuta
(Taras Shevchenko National University of Kiev)
24/09/18, 18:40
Poster
Crystal LiH is one of the best objects for creation of effective sources of hard radiation, generated by electron channeling. We have calculated the interaction potential of electrons with the main charged axes [110] of LiH and also found the radiation spectrum in this potentialal. These calculations were based on one-particle potentials for Li+ and Н– ions in a lithium hydride (LiH) crystal...
Prof.
Vladimir Baryshevsky
(Belarusian state University, Institute for Nuclear Problems)
24/09/18, 18:40
Poster
Combining the photonic crystal-based structures with vacuum electronic devices opens the way for creation of a family of radiation sources: photonic BWOs, volume FELs (VFEL), etc. Some beneficial options of such structures, which enable tunability and increasing the radiation source efficiency, are discussed. The VFEL instability law declares start current for generator with the interaction...
Prof.
Nikolai Shul'ga
(Akhiezer Institute for Theoretical Physics of NSC KIPT)
24/09/18, 18:40
Poster
In the present paper there was investigated on the base of the quantum electrodynamics eikonal approximation the process of charged high-energy particles scattering in ultrathin targets. There was suggested a unified approach that allows one to consider the scattering of particles in this case in both amorphous and crystalline targets from a single point of view.
Particular attention was paid...
Dr.
Sergey Galyamin
(Saint Petersburg State University)
24/09/18, 18:40
Poster
In this report, we study electromagnetic field produced by a charged particle bunch exiting an open-ended circular waveguide with dielectric filling placed inside collinear vacuum waveguide of a larger radius. We suppose that the bunch is prolonged along its trajectory and negligibly thin in the orthogonal direction. Based on the previously developed theory, we mainly investigate Cherenkov...
Dr.
Tatiana Alekhina
(SPbSU, Saint-Petersburg, Russia)
24/09/18, 18:40
Poster
Investigation of the field of a particle bunch in a waveguide loaded with dielectric is important for the wakefield acceleration technique and for other problems in the accelerator physics. Problems of producing high acceleration fields bring to study more effective methods, for example, with using anisotropic materials. Here we study the dielectric anisotropy influence on radiation of a bunch...
Sig.na
Xiatong Li
(Tomsk Polytechnic University)
24/09/18, 18:40
Poster
In the present report, we study the spin rotation of muons and anti – muons moving in a bent crystal in planar channeling regime. For this purpose, we find particle’s trajectory in the crystal. Using calculated trajectory we find exact solution of the BMT equation and calculated the angel of muon (anti - muons) spin rotation. The result of calculation is compared with one for spin rotation of...
Sig.
Koryun Gevorgyan
(Yerevan State University (student))
24/09/18, 18:40
Poster
The problem of channeling radiation of positron bunch in the system of packed nanotubes is investigated. An expression is obtained for the spectral distribution of the total radiation of a positron bunch. The spectral distribution, taking into account the inhomogeneity of the polarization of the medium, differs significantly from the case when the averaged homogeneous polarization of the...
Sig.na
Dina Badreeva
(National Research Nuclear University MEPhI)
24/09/18, 18:40
Poster
The capture process of the high energy particle into the axial channeling state in single crystal if considered in the laboratory reference system is a sufficiently relativistic process. The cross-section calculation of this process, especially in case when the electrons capture is accompanied by the emission of a high energy photon in ultra-relativistic case is not trivial and not very clear....
Dr.
Oleg Bogdanov
(TSU&TPU)
24/09/18, 18:40
Poster
The concept of channeling in a Half-Wave Crystal (HWC) was proposed in [1-3] for a proton beam. In our previous works [4,5], the processes of scattering and radiation of relativistic electrons channeled in a Si HWC according the beam parameters of the SAGA LS accelerator (Japan) were studied in detail.
It is known, that the radiation from channeled electrons in a straight crystal has...
Sig.
Hayk Gevorgyan
(Student)
24/09/18, 18:40
Poster
The problem of optical radiation produced by a bunch of relativistic positrons channeled to a crystalline undulator (CU) is considered. Taking into account the polarization of the crystal medium, an energy threshold takes place to form the radiation. If the energy of the bunch is above the threshold, the radiation is created in a limited frequency range. Both soft and hard boundary photons...
Sig.
Yury Eikhorn
(National Research Tomsk Polytechnic University)
24/09/18, 18:40
Poster
CR in both optical and ultraviolet regions occurs under the condition n > 1 for the crystal refractive index (see [2]), i.e. at the large angles to the direction of motion for channeled particles - near Cherenkov angle.
This radiation can be used, for example, in biomedical research. In modern medical clinics the proton accelerators are in active use. By supplementing at such medical...
