4,651 research outputs found

    Dependence of effective spectrum width of synchrotron radiation on particle energy

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    For an exact quantitative description of spectral properties in the theory of synchrotron radiation, the concept of effective spectral width is introduced. In the classical theory, numeric calculations of effective spectral width (using an effective width not exceeding 100 harmonics) for polarization components of synchrotron radiation are carried out. The dependence of the effective spectral width and initial harmonic on the energy of a radiating particle is established

    Effective spectrum width of the synchrotron radiation

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    For an exact quantitative description of spectral properties of synchrotron radiation (SR), the concept of effective width of the spectrum is introduced. In the most interesting case, which corresponds to the ultrarelativistic limit of SR, the effective width of the spectrum is calculated for the polarization components, and new physically important quantitative information on the structure of spectral distributions is obtained. For the first time, the spectral distribution for the circular polarization component of the SR for the upper half-space is obtained within classical theory

    Numerical model of Electron Cyclotron Resonance Ion Source

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    Important features of Electron Cyclotron Resonance Ion Source (ECRIS) operation are accurately reproduced with a numerical code. The code uses the particle-in-cell technique to model a dynamics of ions in ECRIS plasma. It is shown that gas dynamical ion confinement mechanism is sufficient to provide the ion production rates in ECRIS close to the experimentally observed values. Extracted ion currents are calculated and compared to the experiment for few sources. Changes in the extracted ion currents are obtained with varying the gas flow into the source chamber and the microwave power. Empirical scaling laws for ECRIS design are studied and the underlying physical effects are discussed.Comment: 24 pages, 41 figure

    Interaction of the Church and Society in Commemoration Campaigns Activated By Museum of Sanctity and Asceticism in the Urals in 20

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    The article analyzes attempts of the Orthodox Church and secular society to form some integrated space of historical memory about repressions in the Urals in the 2

    Numerical simulations of gas mixing effect in Electron Cyclotron Resonance Ion Sources

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    The particle-in-cell MCC code NAM-ECRIS is used to simulate the ECRIS plasma sustained in a mixture of Kr with O2, N2, Ar, Ne and He. The model assumes that ions are electrostatically confined in ECR zone by a dip in the plasma potential. Gain in the extracted krypton ion currents is seen for the highest charge states; the gain is maximized when oxygen is used as the mixing gas. A special feature of oxygen is that most of singly charged oxygen ions are produced after dissociative ionization of oxygen molecules with the large kinetic energy release of around 5 eV per ion. Increased loss rate of energetic lowly charged ions of the mixing element requires building up of the retarding potential barrier close to ECR surface to equilibrate electron and ion losses out of the plasma. In the mixed plasmas, the barrier value is large (~1 V) compared to the pure Kr plasma (~0.01 V), with the longer confinement times of krypton ions and with the much higher ion temperatures

    On Optical Properties Of Ion Beams Extracted From Electron Cyclotron Resonance Ion Source

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    Ion extraction from DECRIS-PM source is simulated by using initial distributions of ions at the extraction aperture obtained with NAM-ECRIS code. Three-dimensional calculations of plasma emissive surface are done and ions are traced in the extraction region. The ion beam profiles show strong aberrations due to shape of plasma meniscus; hollow beam features are reproduced, as well as changes in profiles for different focusing conditions

    NbS3_{3}: A unique quasi one-dimensional conductor with three charge density wave transitions

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    Through transport, compositional and structural studies, we review the features of the charge-density wave (CDW) conductor of NbS3_{3} (phase II). We highlight three central results: 1) In addition to the previously reported CDW transitions at TP1T_{P1} = 360\,K and TP2T_{P2} = 150\,K, another CDW transition occurs at a much higher temperature TP0T_{P0} = 620-650\,K; evidence for the non-linear conductivity of this CDW is presented. 2) We show that CDW associated with the TP2T_{P2} - transition arises from S vacancies acting as donors. Such a CDW transition has not been observed before. 3) We show exceptional coherence of the TP1T_{P1}-CDW at room-temperature. Additionally, we report on the effects of uniaxial strain on the CDW transition temperatures and transport.Comment: 16 pages, 18 figure
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