The Goals of Upgrading the ATLAS Tracker System
The Goals of Upgrading the ATLAS Tracker System
V. V. Sinetckii$^{1,2}$, L. N. Smirnova$^1$
The review presents the stages of modernization of the tracker system of the ATLAS detector at the Large Hadron Colider (LHC). The period from the moment of the detector creation to its further operation in the high luminosity mode of the HL-LHC is considered. Changes of the detector design at different stages, resolution when measuring tracks of charged particles, the quality of the recovery of vertices under conditions of high luminosity of the collider, leading to simultaneous recording of 200 events on average with the birth of two or more charged particles during collisions of proton bunches are shown. The physical goals are indicated, for the solution of which the realizable and planned changes of the ATLAS track system are critical.
Show AbstractDemonstration of complex rotational motion of a rigid body
Demonstration of complex rotational motion of a rigid body
S. S. Krotov$^1$, S. A. Shuteev$^1$, V. G. Yelenskii$^1$
Taking a “rotating tube” as a starting point to demonstrate a rigid body motion peculiarities, several advanced options of such a things are offered to visualize the corresponding concepts in kinematics, with the instantaneous axis of rotation having a special priority. The significant difference in behavior of the devices under consideration from other nonlinear systems concerns the time needed for the achievement of stationary phases. The corresponding time intervals are found to be finite, as opposed to exponential ones widely spread in nonlinear processes – due to dry friction.
Show AbstractBeam dynamics in the racetrack microtron with a harmonic cavity
Beam dynamics in the racetrack microtron with a harmonic cavity
M. A. Borisov, V. I. Shvedunov
One of the main disadvantages of both classical and split microtron is a small region of stable phase oscillations, which directly affects the value of the output current of the accelerator, greatly reducing it. To increase it, an additional harmonic of the reproducing field is introduced in this paper. Theoretical calculations and computer modeling were performed, which showed an increase in the region when the second harmonic was added.
Show AbstractAcoustical Waves in the Wedge of Lithium Niobate Crystal
Acoustical Waves in the Wedge of Lithium Niobate Crystal
A. I. Korobov$^1$, A. A. Agafonov$^1$, A. I. Kokshayskiy$^1$, M. Yu. Izosimova$^1$
Experimental studies of the features of nonlinear propagation of harmonic acoustic waves in wedges made of an anisotropic lithium niobate crystal are carried out. The effect of fast dynamics, nonlinear absorption and generation of the second and third harmonics of the wedge elastic waves are observed.
Show AbstractNew reliable data on the photodisintegration of 160Gd
New reliable data on the photodisintegration of 160Gd
V. V. Varlamov$^1$, V. D. Kaydarova$^2$, V. N. Orlin$^1$
Using objective physical reliability criteria, experimental data on the cross sections for partial photoneutron reactions on the 160Gd, obtained on the beams of quasimonoenergetic annihilation photons and methods for separation of neutron multiplicity were analyzed. It was established that the experimental cross sections of partial reactions (γ, 1n), (γ, 2n) and (γ, 3n) don’t satisfy the introduced criteria. The new data for partial and total photoneutron reactions for 160Gd cross sections were obtained using the experimental–theoretical method of evaluating the cross sections of the partial reactions, satisfying the reliability criteria. The noticeable deviations of the experimental cross sections from the evaluated once resulted from the unreliable sorting of neutrons between the channels with multiplicities were found.
Show AbstractIn-situ profile measurement of a focused synchrotron radiation beam by a fluorescence detector with a dynamic range of 1E6
In-situ profile measurement of a focused synchrotron radiation beam by a fluorescence detector with a dynamic range of 1E6
S. S. Makarov$^{1,2}$, S. A. Pikuz$^3$, A. P. Chernyeav$^4$
The use of fluorescent detectors is considered extremely promising for the registration of super-intensive X-ray beams. This is due to a number of advantages of such detectors in comparison with traditional detectors (such as CCD, diodes, X-ray films, etc.). In particular, this type of detectors has submicron spatial resolution, simultaneously with a large field of view (up to several cm2). It is also known that the dynamic range of a fluorescent detector ( lithium fluoride crystal – LiF) for soft X-ray radiation significantly exceeds the dynamic range of conventional detectors 1E4. In the framework of this work, the possibility of in-situ profile measurement of a focused synchrotron radiation with ultra-wide dynamic range 1E6 using a fluorescent detector (lithium fluoride crystal-LiF) and a confocal laser scanning microscope are presented.
Show AbstractCapabilities of fully populated multi-element ultrasound phased arrays for noninvasive surgical destruction of deep brain structures using shock waves
Capabilities of fully populated multi-element ultrasound phased arrays for noninvasive surgical destruction of deep brain structures using shock waves
P. B. Rosnitskiy$^1$, I. L. Stepanov$^1$, P. V. Yuldashev$^1$, L. R. Gavrilov$^2$, O. A. Sapozhnikov$^1$, V. A. Khokhlova$^1$
Three models of multi-element ultrasound phased arrays for shock-wave surgical destruction of deep brain structures through an intact skull are proposed. The arrays contain 256, 512, and 1024 elements and have the maximum dense filling of their surface with the elements. Unlike the existing systems of ultrasound neurosurgery, these arrays can realize not a thermal but a mechanical mechanism of tissue ablation (boiling histotripsy). Such approach permits to avoid undesirable overheating and damage to the skull bones. The proposed arrays are much more compact as compared to the existing systems. The arrays have the shape of a spherical segment with an aperture of 200 mm, whereas existing arrays have the shape of a hemispherical bowl with a diameter of 300 mm. Comparative analysis of focus steering capabilities is performed and the possibility of creating volumetric lesions larger than 20 mm in each dimension is shown for all proposed arrays. Nonlinear simulation demonstrated the possibility of reaching focal waveforms with developed shock fronts higher than 70 MPa, required for boiling histotripsy method. Taking into account energy losses when focusing through the skull bones and brain tissues, the intensity at the elements of the arrays does not exceed maximum permissible value of 40 W/cm2.
Show AbstractEvolution of nuclear structure concepts: from the liquid drop to quark-gluonic interactions in nuclei
Evolution of nuclear structure concepts: from the liquid drop to quark-gluonic interactions in nuclei
B. S. Ishkhanov$^{1,2}$, D. E. Lanskoy$^2$
Evolution of nuclear structure concepts is traced from the simplest drop and single-particle shell models in view of the Thomas Jefferson Lab (USA) experiment, in which short-range correlations of nucleons in nuclei have been studied. It is argued that treatment of the short-range correlations requires theoretical consideration of subnucleonic (quark and gluonic) degrees of freedom in nuclei.
Show AbstractWavelet analysis of audiosignals and speech synthesis
Wavelet analysis of audiosignals and speech synthesis
S. A. Nikonorov, A. N. Bogolubov
The speech analysis and approximation algorithm based on the continuous wavelet transform was created. In the current work, audiofiles from the Zuiga Mizuki voice bank were analised and some of them (namely vowel sound files) were synthesised using the suggested algorithm.
Show AbstractThe noise immunity increasing of the communication systems with OFDM-signals using the wavelet transform
The noise immunity increasing of the communication systems with OFDM-signals using the wavelet transform
E. N. Rychkov$^1$, Yu. A. Pirogov$^2$
The communication systems with OFDM-signals have been considered in a comparison with the classic communication systems, which are based on amplitude, frequency and phase modulation types. The possibilily of usage the wavelet transform instead of Fourier transform in such systems has been investigated. The experiment has been done with a matching of received information in two types of OFDM-systems: with Fourier and wavelet transforms. There has been shown that wavelet-basis can lead to the benefit with a selective fadding, so as information in such a signal is not localized in frequency domain, but, on the other hand, is not blurred in the time domain. Thus, the possibility has been demonstrated to build new communication systems, in which the optimal parameters of the system are not distributed in several algorithms, but are concentrated in wavelet transform. Such several algorithms in common OFDM-systems are interleaving coding, OQAM-IOTA, FBMC and others.
Show Abstract