Upgrading of the high-current accelerator “Tonus”

In the paper presented, the new technical development of the high-current electron accelerator “Tonus-NT” (Tomsk nanosecond accelerator – new technologies) is described. It has been developed taking into account the experience of 30-years exploitation of the previous analogue – the accelerator “Tonus”. The scheme of the accelerator includes the high-voltage transformer with resonant contours (Tesla transformer) charging the double forming line filled with the transformer oil and the high-voltage diode. The gas-filled trigatron spark gap with up to 10 atm operating pressure is used for the double forming line switching. The main accelerator parameters are as follows: accelerating voltage range 0.4-1.7 MeV, line impedance 36.6 Ω, pulse duration 60 ns, pulse repetition rate up to 10 pps

On Asymptotic Expansion in the Random Allocation of Particles by Sets

We consider a scheme of equiprobable allocation of particles into cells by sets. The Edgeworth type asymptotic expansion in the local central limit theorem for a number of empty cells left after allocation of all sets of particles is derived.Comment: 15 page

Progress in 433 MHz RFQ technology at NPK LUTS NIIEFA

The paper is a survey of progress in 433 MHz RFQ technology at Production Complex of Linacs and Cyclotrons of D.V. Efremov Institute Sci. over past three years. RFQs and APF-cavities are designed as bases for ion accelerators for different applications. The use of 433 MHz frequency determines high requirements for RFQ manufacture facilities, which are discussed herein. The test experimental results of RFQ full-scale stands and high power rf testing data under beam load of 1 MeV on a deuteron RFQ made of chromium copper are presented.Приведен обзор работ по созданию ПОКФ на 433 МГц в НПК ЛУЦ НИИЭФА им. Д.В. Ефремова за последние три года. ПОКФ и ПФФ-резонаторы планируется использовать в качестве основных резонаторов ускорителей ионов для различных применений. Использование частоты 433 МГц определяет высокие требования для изготовления ПОКФ, которые обсуждены в статье. Представлены экспериментальные результаты тестирования полномасштабных стендов ПОКФ и данные испытаний резонатора из хромистой меди для ускорения дейтронов до энергии 1 МэВ при высоком уровне ВЧ-мощности и нагрузке пучком.Наведено огляд робіт зі створення ПОКФ на 433 МГц у НПК ЛУЦ НІІЕФА ім. Д.В. Єфремова за останні три роки. ПОКФ і ЗФФ-резонатори планується використати як основні резонатори прискорювачів іонів для різних застосувань. Використання частоти 433 МГц визначає високі вимоги для виготовлення ПОКФ, які обговорені в статті. Представлено експериментальні результати тестування повномасштабних стендів ПОКФ і дані випробувань резонатора із хромистої міді для прискорення дейтронів до енергії 1 МеВ при високому рівні ВЧ-потужності і навантаженню пучком

Measurement of RudsR_{\text{uds}} and RR between 3.12 and 3.72 GeV at the KEDR detector

Using the KEDR detector at the VEPP-4M $e^+e^-$ collider, we have measured the values of $R_{\text{uds}}$ and $R$ at seven points of the center-of-mass energy between 3.12 and 3.72 GeV. The total achieved accuracy is about or better than $3.3\%$ at most of energy points with a systematic uncertainty of about $2.1\%$. At the moment it is the most accurate measurement of $R(s)$ in this energy range

New precise determination of the \tau lepton mass at KEDR detector

The status of the experiment on the precise $\tau$ lepton mass measurement running at the VEPP-4M collider with the KEDR detector is reported. The mass value is evaluated from the $\tau^+\tau^-$ cross section behaviour around the production threshold. The preliminary result based on 6.7 pb$^{-1}$ of data is $m_{\tau}=1776.80^{+0.25}_{-0.23} \pm 0.15$ MeV. Using 0.8 pb$^{-1}$ of data collected at the $\psi'$ peak the preliminary result is also obtained: $\Gamma_{ee}B_{\tau\tau}(\psi') = 7.2 \pm 2.1$ eV.Comment: 6 pages, 8 figures; The 9th International Workshop on Tau-Lepton Physics, Tau0

Search for narrow resonances in e+ e- annihilation between 1.85 and 3.1 GeV with the KEDR Detector

We report results of a search for narrow resonances in e+ e- annihilation at center-of-mass energies between 1.85 and 3.1 GeV performed with the KEDR detector at the VEPP-4M e+ e- collider. The upper limit on the leptonic width of a narrow resonance Gamma(R -> ee) Br(R -> hadr) < 120 eV has been obtained (at 90 % C.L.)

Measurement of \Gamma_{ee}(J/\psi)*Br(J/\psi->e^+e^-) and \Gamma_{ee}(J/\psi)*Br(J/\psi->\mu^+\mu^-)

The products of the electron width of the J/\psi meson and the branching fraction of its decays to the lepton pairs were measured using data from the KEDR experiment at the VEPP-4M electron-positron collider. The results are \Gamma_{ee}(J/\psi)*Br(J/\psi->e^+e^-)=(0.3323\pm0.0064\pm0.0048) keV, \Gamma_{ee}(J/\psi)*Br(J/\psi->\mu^+\mu^-)=(0.3318\pm0.0052\pm0.0063) keV. Their combinations \Gamma_{ee}\times(\Gamma_{ee}+\Gamma_{\mu\mu})/\Gamma=(0.6641\pm0.0082\pm0.0100) keV, \Gamma_{ee}/\Gamma_{\mu\mu}=1.002\pm0.021\pm0.013 can be used to improve theaccuracy of the leptonic and full widths and test leptonic universality. Assuming e\mu universality and using the world average value of the lepton branching fraction, we also determine the leptonic \Gamma_{ll}=5.59\pm0.12 keV and total \Gamma=94.1\pm2.7 keV widths of the J/\psi meson.Comment: 7 pages, 6 figure

Measurement of main parameters of the \psi(2S) resonance

A high-precision determination of the main parameters of the \psi(2S) resonance has been performed with the KEDR detector at the VEPP-4M e^{+}e^{-} collider in three scans of the \psi(2S) -- \psi(3770) energy range. Fitting the energy dependence of the multihadron cross section in the vicinity of the \psi(2S) we obtained the mass value M = 3686.114 +- 0.007 +- 0.011 ^{+0.002}_{-0.012} MeV and the product of the electron partial width by the branching fraction into hadrons \Gamma_{ee}*B_{h} = 2.233 +- 0.015 +- 0.037 +- 0.020 keV. The third error quoted is an estimate of the model dependence of the result due to assumptions on the interference effects in the cross section of the single-photon e^{+}e^{-} annihilation to hadrons explicitly considered in this work. Implicitly, the same assumptions were employed to obtain the charmonium leptonic width and the absolute branching fractions in many experiments. Using the result presented and the world average values of the electron and hadron branching fractions, one obtains the electron partial width and the total width of the \psi(2S): \Gamma_{ee} =2.282 +- 0.015 +- 0.038 +- 0.021 keV, \Gamma = 296 +- 2 +- 8 +- 3 keV. These results are consistent with and more than two times more precise than any of the previous experiments