Budker Institute of Nuclear Physics (Siberian Branch, Russian Academy of Sciences) continues to create a high-voltage electron cooling system for the NICA collider, which is necessary to achieve the design luminosity of the complex in ion–ion collisions. The system consists of two independent coolers with an electron energy of up to 2.5 MeV with current of up to 1 A, which simultaneously cool two colliding ion beams. The article describes the status of the system and the results of testing of its elements.

VEPP-2000 is an electron-positron collider with round beams built and operating at the Budker Institute of Nuclear Physics. The integrated luminosity accumulated over last 2 years has reached 0.5 fb–1 with peak luminosity of 0.9 × 1032 cm–2 s–1. The short description of the VEPP-2000 complex and current status with achieved results are presented.

The VEPP-5 injection complex is a source of electron and positron beams for the VEPP-2000 and VEPP-4 complexes and is considered as an injector for the future collider project. The performance of the complex is sufficient for current users, but needs to be improved to serve future setups. Work is underway at the injection complex to improve the stability of operation and ease of use. Current achievements and planned improvements of the injection complex are described.

This paper describes an approach enabling the continuous monitoring of all devices on the Synchrotron Radiation Facility Siberian Circular Photon Source (SRF SKIF) accelerator complex units synchronically with the measurements of beam parameters. The operation of devices is monitored in distributed controllers with a frequency of 10 kHz. After detecting any deviations from specified parameters above the tolerance value in the operation of a device, the controller of this device sets a corresponding signal. When a beam exhibits an abnormal behavior, the comparative analysis of synchronous data from the distributed controllers and the beam diagnosing electronics is performed to reveal the device resulting in such a behavior.

— The review presents the experiments performed with the KEDR detector at the e^ + e^ - collider VEPP-4M in the energy range of √(s) = 1.84–3.88 GeV. The cross section of e^ + e^ - annihilation to hadrons was measured at 22 points of this range and the search for narrow resonances was conducted below 3.1 GeV. The masses of J / . -0emψ and ψ (2S) mesons were measured with a record accuracy better than 3 ×10^ - 6 ; their partial and total widths were determined. Measurements of the tau lepton mass and masses of charged and neutral D mesons were performed with high precision. The measurements of the ψ (3770) parameters are discussed, and attention is drawn to some inconsistency of the procedure employed by the Particle Data Group for determining its parameters.

The VEPP-5 injection complex is a source of intense electron and positron beams that supplies the VEPP-4M and VEPP-2000 accelerator complexes through the K-500 transport channel. At present, the injection complex is in regular operation. Work is being carried out to improve the performance and stability of the facility, and possible ways of working with perspective beam users are being considered. This article presents a description of the injection complex and the experience of its operation, as well as the latest improvements being considered.

Tune measurement system developed in Budker Institute of Nuclear Physics for the Booster of the SKIF project provides fast and accurate measurements of fractional part of betatron tunes during Booster acceleration cycle. Resonance excitation of betatron oscillations with help of radio frequency (RF) pulses feeding to the kiker electrodes is used in the system. The minimal tune measurement time is 1.3 ms, which allows having tunes measurement data for each phase of the Booster accelerating cycle. The system can perform up to 256 measurements during 400 ms time interval of Booster energy ramping. The tune measurement accuracy is better than 0.001 f 0 , where f 0 is Booster revolution frequency.

We present the study of the decay J/ψ → ρπ . The results are based on of 5.2 million J/ψ events collected by the KEDR detector at the VEPP-4M collider. The branching fractions are measured to be ℬ ( J/ψ → ρπ ) = (2 . 072 ± 0 . 017 ± 0 . 062) ∙ 10 − 2 and ℬ ( J/ψ → π + π − π 0 ) = (1 . 878 ± 0 . 013 ± 0 . 051) ∙ 10 − 2 , where the first uncertainties are statistical and the second systematic. Our results are more precise than the previous relative measurements.

The VEPP-2000 is an electron–positron collider with round beams built and operating at the Budker Institute of Nuclear Physics (BINP). The collider luminosity was increased twofold last year. The integrated luminosity accumulated over the last year has exceeded 0.3 fb –1 , which almost doubled the total data collected since the collider operation began. The short description of the VEPP-2000 complex, current status, and the results are presented in this work.

Using a low-pressure flow reactor, the kinetic regularities of the reaction of atomic fluorine with monochloroacetic acid at temperature T = 293 K are studied. The concentrations of the reagents are monitored by molecular beam mass spectrometry, detecting the molecular peaks of the substances. Using the published data, the value of the reaction rate constant $$k = (9.6 \pm 3.8) \times {{10}^{{ - 11}}}$$ cm3 molecules–1 s–1, which is the average value determined by comparison with the rate constants of competing reactions (kref), is calculated. The ratios of the rate constants k/kref, equal to 0.99 ± 0.12 and 0.75 ± 0.04, respectively, are determined for two competing reactions: a fluorine atom with 2-fluoroethanol and a fluorine atom with cyclohexane. The rate constants of the reaction of atomic fluorine with monochloroacetic acid are compared with the rate constants of reactions of atomic fluorine with chlorine-substituted acetic acids: dichloroacetic and trichloroacetic acids.

Using the 1.32 pb^-1 statistics collected at the J/ψ peak with the KEDR detector at the VEPP-4M e^+e^- collider, we measured the branching fractions of J/ψ meson decays to the final states 2( π ^+π ^-)π ^0 , K^+K^-π ^+π ^-π ^0 , 2( π ^+π ^-) and K^+K^-π ^+π ^- . The results obtained for the decays J/ψ→ 2( π ^+π ^-)π ^0 , J/ψ→ K^+K^-π ^+π ^-π ^0 contradict the measurements performed by other groups in the last century, but agree well with recent results of BABAR and BESIII collaborations.

Abstract Using the 1.32 $$\hbox {pb}^{-1}$$ pb - 1 statistics collected at the $$J/\psi $$ J / ψ peak with the KEDR detector at the VEPP-4M $$e^{+}e^{-\, }$$ e + e - collider, we measured the branching fractions of $$J/\psi $$ J / ψ meson decays to the final states 2( $$\pi ^{+}\pi ^{-})\pi ^{0}$$ π + π - ) π 0 , $$K^{+}K^{-}\pi ^{+}\pi ^{-}\pi ^{0}$$ K + K - π + π - π 0 , 2( $$\pi ^{+}\pi ^{-})$$ π + π - ) and $$K^{+}K^{-}\pi ^{+}\pi ^{-}$$ K + K - π + π - . The results obtained for the decays $$J/\psi \rightarrow $$ J / ψ → 2( $$\pi ^{+}\pi ^{-})\pi ^{0}$$ π + π - ) π 0 , $$J/\psi \rightarrow K^{+}K^{-}\pi ^{+}\pi ^{-}\pi ^{0}$$ J / ψ → K + K - π + π - π 0 contradict the measurements performed by other groups in the last century, but agree well with recent results of BABAR and BESIII collaborations.

Using the 1.32 pb(-1) statistics collected at the J/psi peak with the KEDR detector at the VEPP-4M e(+)e(-) collider, we measured the branching fractions of J/psi meson decays to the final states 2(pi(+)pi(-))pi(0), K+K- pi(+)pi(-)pi(0), 2(pi(+)pi(-)) and K+K- pi(+)pi(-). The results obtained for the decays J/psi -> 2(pi(+)pi(-))pi(0), J/psi -> K+K- pi(+)pi(-)pi(0) contradict the measurements performed by other groups in the last century, but agree well with recent results of BABAR and BESIII collaborations.

Using the 1.32 pb^-1 statistics collected at the J/ψ peak with the KEDR detector at the VEPP-4M e^+e^- collider, we measured the branching fractions of J/ψ meson decays to the final states 2( π ^+π ^-)π ^0 , K^+K^-π ^+π ^-π ^0 , 2( π ^+π ^-) and K^+K^-π ^+π ^- . The results obtained for the decays J/ψ→ 2( π ^+π ^-)π ^0 , J/ψ→ K^+K^-π ^+π ^-π ^0 contradict the measurements performed by other groups in the last century, but agree well with recent results of BABAR and BESIII collaborations.

We review the recent results obtained by the KEDR experiment in the charmonium energy range. They include the measurements of J/psi meson total and partial widths and exclusive branching fractions, study of D+ and D-0 meson masses and R between 1.8 and 7.0 GeV.

The project of new accelerator complex NICA relating to nuclear and hadron physics require a more powerful longitudinal and transverse cooling that stimulates searching new technical solutions. The new accelerator complex NICA is designed at the Joint Institute for Nuclear Research (JINR, Dubna, Russia) to do experiment with ionion and ion-proton collision in the energy range 1-4.5 GeV/u for studying the properties of dense baryonic matter at extreme values of temperature and density with planned luminosity 1027 cm-2s-1. This value can be obtained with help of very short bunches with small transverse size. This beam quality can be realized with help of stochastic and electron cooling at energy of the physics experiment. The electron cooling system on 2.5 MeV consists of two coolers, which cool both ion beams simultaneously. The Budker Institute of Nuclear Physics (BINP SB RAS) has already built and commissioned the electron cooling system for the NICA booster, and now it develops the high voltage electron cooling system for the collider. The article describes the construction and status of the cooler development.

The mass spectra of negative ions of aqueous solutions of completely neutralized monochloroacetic acid (MCA), dichloroacetic acid (DCA), and trichloroacetic acid (TCA) with a concentration of 0.01 mol/L at 20°C are obtained by the mass spectrographic method of electrospraying electrolyte solutions in vacuum. In all the distributions according to the degree of hydration of the acid residue, the dependence of the ion current intensity on the number of water molecules in the ion current is found. At an acid concentration of 0.01 mol/L, the number of hydrated monochloroacetic and dichloroacetic ions decreases monotonically with the increasing degree of hydration. For a TCA solution, the ion current intensity reaches the maximum of the distribution for two water molecules in the ion.