Timing Observations of 27 Pulsars at the Pushchino Observatory from 1978 to 2012

We present results from timing observations of 27 pulsars made at the Pushchino Observatory over 33.5 yr between 1978 July and 2012 February. We also analyze archival Jet Propulsion Laboratory data of 10 pulsars to extend individual data span to 43.5 yr. We detected a new phenomenon in the timing behavior of two pulsars, B0823+26 and B1929+10, that demonstrates a rapid change of pulsar rotation parameters such that the sign of the second derivative $\ddot\nu$ is reversed. An analysis of the $\ddot\nu$ changes showed that this process can be considered as a modulation process in $\ddot\nu$. We showed that the process of rapidly changing of pulsar rotation parameters represents a new type of rotational irregularity that, together with three other types of rotational irregularities (discrete glitches, slow glitches and quasi-periodic oscillations), forms a large-scale structure of timing noise. These effects are all the cause of the deviation of the timing behavior of most ordinary pulsars from a simple $\nu,\,\dot\nu$ spin-down model. We found that all four types of observed rotational irregularities have evolving nature. Irregularities in pulsar rotation rate pass through three evolutional stages that show that a certain type of rotational irregularity can occur only at a certain stage of pulsar rotation evolution. The age boundaries between different evolutionary stages are indistinct and diffusive. This fact is because different pulsars having similar properties evolve along different paths. The evolutionary scenario of the occurrence of rotational irregularities explains well many of the observed properties of pulsar rotation.Comment: 66 pages, 17 figures. ApJ,775,2(2013

Low Frequency Radio Emission of Pulsar PSR J1907+0919 Associated with the Magnetar SGR 1900+14

The soft gamma repeater SGR 1900+14 was observed in Pushchino observatory since 1988 December using BSA radio telescope operating at 111 MHz. We have detected the pulsed radio emission (Shitov 1999) with the same 5.16 s period that was reported earlier for this object. The timing analysis has shown that this new radio pulsar PSR J1907+0919 associated with SGR 1900+14 has a superstrong magnetic field, which is 8.1 * 10^14 G, thereby confirming that it is a "magnetar". The dispersion measure of PSR J1907+0919 is 281.4(9) pc * cm^(-3) which gives an estimate of the pulsar's distance as about 5.8 kpc.Comment: 5 pages, 3 figures, newpasp.sty, to be published in Pulsar Astronomy - 2000 and Beyond, ASP Conference Serie

DQM Tools and Techniques of the SND Detector

SND detector operates at the VEPP-2000 collider (BINP, Novosibirsk). To improve events selection for physical analysis and facilitate online detector control we developed new data quality monitoring (DQM) system. The system includes online and reprocess control modules, automatic decision making scripts, interactive (web based) and program (python) access to various quality estimates. This access is implemented with node.js server with data in RDBMS MySQL. We describe here general system logics, its components and some implementation details

Spatial distributions of plasma potential and density in electron cyclotron resonance ion source

The Numerical Advanced Model of Electron Cyclotron Resonance Ion Source (NAM-ECRIS) is applied for studies of the physical processes in the source. Solutions of separately operating electron and ion modules of NAM-ECRIS are matched in iterative way such as to obtain the spatial distributions of the plasma density and of the plasma potential. Results reveal the complicated profiles with the maximized plasma density close to the ECR surface and on the source axis. The ion-trapping potential dips are calculated to be on the level of ~(0.01-0.05) V being located at the plasma density maxima. The highly charged ions are also localized close to the ECR surface. The biased electrode effect is due to an electron string along the source axis formed by reflection of electrons from the biased electrode and the extraction aperture. The string makes profiles of the highly charged ions more peaked on the source axis, thus increasing the extracted ion currents

Three-dimensional modelling of processes in Electron Cyclotron Resonance Ion Source

Three-dimensional numerical model is developed and applied for studies of physical processes in Electron Cyclotron Resonance Ion Source. The model includes separate modules that simulate the electron and ion dynamics in the source plasma in an iterative way. The electron heating by microwaves is simulated by using results of modelling the microwave propagation in the plasma by the COMSOL Multiphysics software. Extracted ion currents and other parameters of the source are obtained for different gas flows into the source. It is observed that the currents are strongly influenced by ion transport in transversal direction induced by the plasma potential gradients. Impact of some special techniques on the source performance is investigated. Magnetic field scaling is shown to reduce the ion losses during their movement toward the extraction aperture, as well as use of the aluminum chamber walls and mixing of the working gas with helium

On optimization of the metal ion production by Electron Cyclotron Resonance Ion Sources

The three-dimensional NAM-ECRIS model is applied for studying the metal ion production in the DECRIS-PM Electron Cyclotron Resonance Ion Source. Experimentally measured extracted ion currents are accurately reproduced with the model. Parameters of the injection of metal vapors into the source are optimized. It is found that the axial injection of the highly directional fluxes allows increasing the extracted ion currents of the highly charged calcium ions by factor of 1.5. The reason for the gain in the currents is formation of internal barrier for the ions inside the plasma, which increase the ion extraction and production efficiency. Benefits of injecting the singly-charged calcium ions instead of atoms are discussed

Measurement of the e+e−→π0γe^+e^- \to \pi^0\gamma cross section in the energy range 1.075--2 GeV at SND

The process $e^+e^- \to \pi^0\gamma$ is studied with the SND detector at the VEPP-2000 $e^+e^-$ collider. Basing on data with an integrated luminosity of 41 pb$^{-1}$ recorded in 2010-2012 we measure the $e^+e^- \to \pi^0\gamma$ cross section in the center-of-mass energy range from 1.075 up to 2 GeV. In the range 1.4-2.0 GeV the process $e^+e^- \to \pi^0\gamma$ is studied for the first time.Comment: 7 pages, 5 figures. arXiv admin note: text overlap with arXiv:1601.0806

Measurement of the e+e−→KSKLπ0\mathbf{e^+e^- \rightarrow K_S K_L \pi^0} cross section in the energy range s=1.3−2.0\mathbf{\sqrt{s}=1.3-2.0} GeV

The $e^+e^- \rightarrow K_S K_L \pi^0$ cross section is measured in the center-of-mass energy range $\sqrt{s}=1.3-2.0$ GeV. The analysis is based on the data sample with an integrated luminosity of 33.5 pb$^{-1}$ collected with the SND detector at the VEPP-2000 $e^+e^-$ collider.Comment: 8 pages, 3 figures, accepted for publication in Phys. Rev.

Measurement of the e+e−→ηπ+π−e^+e^- \to \eta\pi^+\pi^- cross section with the SND detector at the VEPP-2000 collider

The $e^+e^- \to \eta\pi^+\pi^-$ cross section is measured at the SND detector in the $\eta$ decay mode $\eta\to 3\pi^0$. The analysis is based on the data sample with an integrated luminosity of 32.7 pb$^{-1}$ collected at the VEPP-2000 $e^+e^-$ collider in the center-of-mass energy range $\sqrt{s}=1.075-2.000$ GeV. The data obtained in the $\eta\to 3\pi^0$ decay mode are found to be in agreement with the previous SND measurements in the $\eta\to \gamma\gamma$ mode. Therefore the measurements in the two modes are combined.Comment: 8 pages, 5 figure

Measurement of the e+e−→π+π−π0ηe^+e^- \to \pi^+\pi^-\pi^0\eta cross section below s=2\sqrt{s}=2 GeV

The process $e^+e^- \to \pi^+\pi^-\pi^0\eta$ is studied in the center-of-mass energy region below 2 GeV with the SND detector at the VEPP-2000 $e^+e^-$ collider. The four intermediate states contribute to this process: $\omega\eta$, $\phi\eta$, $a_0(980)\rho$, and a structureless $\pi^+\pi^-\pi^0\eta$ state. We measure the total $e^+e^- \to \pi^+\pi^-\pi^0\eta$ cross section and the cross sections for its components: $\omega\eta$, $\phi\eta$, and a sum of $a_0(980)\rho$ and the structureless state. Our results are in agreement with previous measurements and have comparable or better accuracies.Comment: 17 pages, 11 figures, 3 tables. arXiv admin note: text overlap with arXiv:1607.0037