Conveners
PS1: Poster Session
- Andrea Liedl (LNF)
Dr
Erine Babakhanyan
(National Research Laboratory after A.I. Alikhanian (Yerevan Physics Institute), Armenia)
26/09/2016, 18:40
The motion of a charged particle in a one-dimensional periodic potential of the Kronig-Penney type is considered. The energy band structure, Bloch wave functions in coordinate and momentum representation are investigated in detail. Two sharply distinguished groups of states, i.e. below-barrier and above-barrier, are extracted and the role of both of them in the channeling of positively and...
Dr
Yuichi Takabayashi
(SAGA Light Source)
26/09/2016, 18:40
Poster
When a relativistic charged particle is incident on a crystalline target, parametric X-ray radiation (PXR) is produced in the Bragg direction [1]. This radiation process can be regarded as diffraction of virtual photons associated with the incident particle. Recently, PXR has been studied as a new beam diagnostic method [2-5]. In such studies, measurements of PXR angular distributions are...
Mr
Sergei Abdrashitov
(National Research Tomsk Polytechnic University)
26/09/2016, 18:40
Poster
Recently, the effect of mirroring of sub-GeV electrons by a thin Si half-wave crystal (HWC) was experimentally observed and explained by computer simulations [1]. The features of corresponding radiation spectra [2] at HWC channeling are described using the code BCM-1 [3]. This code was also used earlier in calculations of positrons yield using channeling radiation [4].
The first estimation...
Prof.
Nikolay Kalashnikov
(National Research Nuclear University Mephi)
26/09/2016, 18:40
Poster
It is well known [1-2] that the particle trajectory in a axial symmetric potential U(r), is defined by two-dimensional equation of motion with effective potential Ueff(r)=U(r) + Mz2/2mr2, where m is the particle mass and Mz is its conserved angular momentum. The transversal movement of electrons or positrons in axial channeling mode must be considered in quantum approach based on the...
Prof.
Alexander Potylitsyn
(Tomsk Polytechnic University)
26/09/2016, 18:40
Poster
As a rule, an intensity spectrum of undulator radiation (UR) is calculated in the classical approach even for electron energy larger than 10 GeV. Such a spectrum is determined by an electron trajectory in an undulator neglecting by radiation losses. Using the Planck's law, the UR photon spectrum can be calculated from the obtained intensity spectrum both for linear and nonlinear...
Prof.
Alexander Potylitsyn
(Tomsk Polytechnic University),
Alexey Gogolev, Dr
Anton Babaev
(Tomsk Polytechnic University)
26/09/2016, 18:40
Poster
Parametric X-radiation (PXR) is generated by electrons of crystalline target when the projectiles (electrons) pass through the target. The radiation is amplified at the specific directions due to the periodicity of crystallographic structure, i.e. due to diffraction.
One of the technical challenges in the commissioning and operation of modern accelerators is the measurement and diagnostics...
Prof.
Yuri Kunashenko
(National Research Tomsk Polytechnic University; Tomsk State Pedagogical University)
26/09/2016, 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 [1].
In a present report using those wave functions we theoretical study the coherent photo-production of e +e- pairs by photons in the crystal taking into consideration the effect of channeling...
Prof.
Nikolai Shul'ga
(Akhiezer Institute for Theoretical Physics of NSC KIPT)
26/09/2016, 18:40
Poster
An investigation on the probability of close collisions of high-energy charged particles in a bent crystal was carried out. On the basis of analytical calculation and numerical simulation we analyzed the dependence of this probability from the orientation of the crystal with respect to the direction of fast charged particles motion. Comparison of the probability of close collisions was done...
Prof.
Akbarali Rasulov
(Ferghana Politehnical Institute)
26/09/2016, 18:40
Poster
Nanoclusters on surfaces are interesting for a wide range of chemical, magnetic, electronic and optical properties. Bimetallic particles can be produced displaying either core-shell structures or forming alloys with, eventually, a segregated surface. The possibilities of synthesis outside equilibrium conditions widely increase the range of possible cluster composition and structure. Such...
Prof.
Yuri Kunashenko
(National Research Tomsk Polytechnic University; Tomsk State Pedagogical University)
26/09/2016, 18:40
Poster
Small-angle particle reflection at the channeling conditions appear when electron is reflected from the crystallographic planes of the crystal [1]. In this work proved existence of quantum resonances in a small-angle reflection of relativistic electrons by a crystal surface, if the crystallographic planes are parallel to a surface. Calculations were based on Kronig–Penney model of potential....
25.
Experimental study of coherent interaction at high-energy in the presence of crystalline defects
Enrico Bagli
(FE)
26/09/2016, 18:40
Poster
The presence of structural defects in a crystal strongly affects the orientational coherent effects of high-energy charged particles. Indeed, the trajectories of charged particles may be abruptly modified by a dislocation or a stacking-fault, causing the particle to dechannel. Two strips, a bent SiGe strip and a bent lithium niobate strip, were exposed to a 400 GeV/c proton beam at ...
Dr
Sergey Kuznetsov
(Tomsk Polytechnic University), Dr
Timur Tukhfatullin
(National Research Tomsk Polytechnic University)
26/09/2016, 18:40
Poster
The energy dependence of the neutrons yield from d(d,n)3He reaction at deuterons energy 7÷12 KeV in the textured TiD2 target (the micro crystals are aligned mainly along <100> direction) was studied recently in [1] using pulsed plasma Hall accelerator with closed electron current (PHA). In Ref. [2] the authors investigated the neutron yield in the same reaction using textured CVD-Diamond and...
Prof.
Nikolai Shul'ga
(Akhiezer Institute for Theoretical Physics of NSC KIPT)
26/09/2016, 18:40
Poster
An investigation on stochastic deflection of high-energy negatively charged particles in a bent crystal was carried out. On the basis of analytical calculation and numerical simulation it was shown that it exists a maximum angle at which most of the beam is deflected. The existence of a maximum, which is taken in the correspondence of the optimal radius of curvature, is a novelty with respect...
Dr
Julia Janz
(Tomsk polytechnic university)
26/09/2016, 18:40
Poster
Radiation of charged particles passing through a set of equidistant ridges on the surface of a single crystal is analyzed. The ridge thickness is a half of the particle trajectory period at channeling in a thick crystal. Passing through such set of half-wave crystals the particle can move on quasi-undulator trajectories [1]. Properties of radiation emitted by swift positrons from such...
Dr
Timur Tukhfatullin
(National Research Tomsk Polytechnic University)
26/09/2016, 18:40
Poster
In Ref. [1] the authors investigated the neutron yield in the d(d,n)3Hе reaction using textured CVD-Diamond and 20 keV deuteron beam from HELIS accelerator which delivers the deuteron beam with small angular and energy divergences. The authors of [1] suggested that the observed enhancement of neutron yield is connected both with the screening and channeling effects.
To clarify the role of...
Mr
Yuri Eykhorn
(National Research Tomsk Polytechnic University)
26/09/2016, 18:40
Poster
The work is devoted to features of parametric X-ray radiation - PXR. On the base of the results obtained in [1] and [2] (and confirmed experimentally in [3]), it is noted that the dependence of maximum intensity on electrons energy for PXR and PXR at channeling (PXRC) is very different. The cause is in band structure of energy levels transverse motion. The relative difference between the...
Dr
Anatoly Sabirov
(Chuvash State University, Cheboksary, Russia)
26/09/2016, 18:40
Poster
The positrons quantum channeling in carbon nanotubes by the numerical solution of the Schrödinger equation in the corresponding paraxial approximation is considered. The spatial redistribution of the positrons flux in the transverse plane during channeling in nanotubes is detected. Also the angular distribution of positrons passed through the nanotube is studied. This distribution is sensitive...
Prof.
Alexander Lobko
(Institute for Nuclear Problems, Belarusian State University)
26/09/2016, 18:40
Poster
Quantum mechanical theory for channeling of relativistic charged particles in the bent crystals is considered. Quantum effects of underbarrier tunneling are essential when the radius of the crystal channel curvature is close to its critical value. In this case the wave functions of the quasi-stationary states corresponding to the particles captured in a channel can be presented in the...
Prof.
Nikolay Kalashnikov
(National Research Nuclear University Mephi)
26/09/2016, 18:40
Poster
Raman Scattering of Photons by the Channeling Electrons
Badreeva D.〖R.〗^1, Kalashnikov N.〖P.〗^1
1 National Research Nuclear University MEPhI, Moscow, Russia
dinkulenok@yandex.ru; kalash@mephi.ru
Abstract. The motion of channeling particles in the accompanying coordinate system can be considered as a two-dimensional atom in the case of axial channeling. The transversal motion of the...
Prof.
Nikolay Kalashnikov
(National Research Nuclear University Mephi)
26/09/2016, 18:40
Poster
In the recent publication [1] the authors had considered the resonance interaction of the laser radiation with ultra-relativistic electrons in planar channeling regime. The idea of the effect was simple: even though the distances between energy levels of channeled electrons and the energies of laser photons may belong to different ranges the Doppler effect bring may help them to match each...
Dr
Oleg Bogdanov
(TPU& TSU)
26/09/2016, 18:40
Poster
The sub-GeV – several GeV electrons channeling radiation (CR) spectrum is characterized by a brilliant maximum at photon energies up to several MeV [1], depending on electron beam energy. This is enough to excite separate nuclear levels (tens or hundreds KeV) and to excite reaction on light Be and D nuclei and even may reach the region of giant dipole resonance (7-8 MeV) in more heavier...
Prof.
Nikolay Kalashnikov
(National Research Nuclear University Mephi),
Sultan Dabagov
(LNF)
26/09/2016, 18:40
Poster
Stimulated Resonance Radiation of Channeling Particles
1,2,3 Dabagov S.B., 2 Kalashnikov N.P.
1 Laboratori Nazionale di Frascati, Istituto Nazionale di Fisica Nucleare, Italy.
2 National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow, Russia.
3 RAS, P.N. Lebedev Physical Institute, Moscow, Russia
Abstract. The motion of channeling...
Dr
Nikolae Maksyuta
(Taras Shevchenko National University of Kiev, Ukraine)
26/09/2016, 18:40
Poster
The formation of protonium atoms at channeling of antiprotons in a hydride lithium crystal is investigated
Prof.
Konstantin Korotchenko
(TPU)
26/09/2016, 18:40
Poster
As it was shown in [1], the radiation intensity of Parametric X-ray Radiation (PXR) for the different types of accelerated nuclei is proportional to Z2.
I our work the same problem is solved for ions. However, in contrast to [1] to calculate PXR radiation intensity, we have used the formula, obtained from the dynamical theory [2] within the framework of multipath approach developed by...
