Physics of Particles and Nuclei Letters最新文献

VITA, a neutron accelerator based on an accelerating tandem with vacuum isolation, has been created and is now operated at Budker Institute of Nuclear Physics. VITA includes a tandem electrostatic particle accelerator with a unique design (accelerator tandem with vacuum insulation) intended for generating a monochromatic proton or deuteron beam with an energy of up to 2.3 MeV and the current up to 10 mA. The facility is equipped with γ, α, and neutron spectrometers and dosimeters. The accelerator is used for the development of boron neutron-capture therapy of malignant tumors, radiation testing of advanced materials, and more recently for measuring cross-sections of nuclear reactions. Reliable determination of the linear thickness of atomic nuclei, interacting with a charged particle beam and impurities and affecting the charged particle braking rate, is of uttermost importance for measuring cross sections of nuclear reactions. The difficulty in determining these parameters may explain the significant variation in the data on cross-sections of nuclear reactions provided by various groups of researchers. The study presents the results of the measurements of cross-sections of some nuclear reactions. Attention is focused on the description of the methods used to measure the thickness and elemental composition of thin investigated layers irradiated by a proton or deuteron beam. The applicability of these methods and their accuracy are discussed; the results obtained are compared. Proposals for the development of the diagnostic for further measurements of cross-sections of nuclear reactions are discussed.

Design parameters of the accelerating cavity with vacuum loads to suppress higher order modes are reported. Features of the cavity design and loads are described. Electrodynamic properties of the cavity, as well as results of the thermohydraulic simulation, are presented.

The LINAC-200 linear accelerator in the Dzhelepov Laboratory of Nuclear Problems at the Joint Institute for Nuclear Research is a new facility constructed to provide electron test beams for particle detector research and development studies of advanced methods of electron beam diagnostics and for applied research. It is planned to use four beam-output channels, each providing electron beams in a specific energy range: channels 1 (5–25 MeV), 2 (25–60 MeV), 3 (60–130 MeV), and 4 (130–200 MeV). Channel 2 is in the final manufacturing stages. The design results of the bending magnets and vacuum chambers for beam-output channel 2, as well as the architecture of the automated control system for the power supply of these bending magnets, are presented.

This paper presents the results of the design of a buncher for a linear accelerator of protons and light ions with a charge-to-mass ratio A/Z from 1 to 3.5 and a beam energy of 7.5 MeV/nucleon. It is developed at the National Research Nuclear University MEPhI and intended for use for scientific and applied purposes. The results of a simulation of electrodynamic, thermal, and mechanical processes are presented.

Over the next two years, AO NIIEFA will manufacture and supply three cyclotron systems for the production of radionuclides.

A quadrupole lens (QL) for the beam extraction system of the DC-140 cyclotron is developed. As a result of this work, a QL from identical blocks of permanent magnets (PMs) in the form of rectangular parallelepipeds has been designed. Incoming inspection of the PM batch is performed. Based on the results, the configuration and location of the magnets have been refined. An algorithm is proposed that includes stages of selecting, grouping, and sorting PMs, pursued in the form of a program code. The approach is applicable to various magnetic systems containing identical PM blocks, and the number of their types is not a limitation for the proposed algorithm.

In the framework of the (U(3) times U(3)) extended Nambu–Jona-Lasinio model, the processes ({{e}^{ + }}{{e}^{ - }} to {{K}^{ + }}{{K}^{ - }}{{pi }^{0}}) and ({{e}^{ + }}{{e}^{ - }} to {{K}^{ + }}{{K}^{ - }}eta ) are described taking into account both ground and first radially excited intermediate meson states. It is shown that channels with radially excited (phi (1680)) meson are dominant in both processes. The influence on the results of the appearance of phase factors of radially excited intermediate states, the existence of which is indicated by experimental data, is discussed.

We examine the unknown nature of the source of accelerating expansion of universe in general relativity which leads many researchers to delve into the evolution of our universe in the framework of modified theory of gravity. Here, specially we investigate on Friedmann–Robertson–Walker (FRW) space time filled with a perfect fluid in (f(R,{{L}_{m}})) modified theory framework formulated by Harko and Lobo (2010), where (R) is the Ricci scalar curvature, ({{L}_{m}}) is the ideal fluid’s Lagrangian. To accomplish this, we use a specific form of (f(R,{{L}_{m}})) gravity as (f(R,{{L}_{m}}) = frac{R}{2} + alpha L_{m}^{n} - beta ), where (alpha ), (beta ), and (n) are positive model parameters. Here we employ the parametrization of the deceleration parameter (q = a - frac{b}{H}) to resolve the modified field equations in the framework of (f(R,{{L}_{m}})) gravity for Friedmann–Robertson–Walker (FRW) metric. The evolution of different cosmological parameters have been examined by means of their graphs. We have also obtained our model parameters with 46 points observational Hubble dataset. We have analysed Energy conditions, statefinder and (Om(z)) diagnostics. Finally we have estimated the present age of the universe. The proposed model behaves as a dark energy model and we come to know that it behaves as the SCDM model during early stage of the universe and (Lambda )CDM model during the late time.

The full stack development of components to modernize the control system has been carried out. The TANGO system is used for the direct control of installations. It includes equipment control, an authorization and authentication system, and database control when saving information directly from TANGO. For the frontend part of the control system, web management is an advantage. Both frontend and backend have been developed, mainly using various tools with the TypeScript operating language.

The results of the magnetic structure correction for the VEPP-5 damping ring are presented. A new target model of the ring with a working tune point different from the old model is prepared. The optics were corrected to match the new structure, and a calibrated model of the ring is obtained. The horizontal orbit in the BPMs was corrected, and transverse shifts of the quadrupole lens magnetic axis relative to this orbit are measured.