[en] A transducer id described based on the measurement of the distribution of ''image currents'' induced by a beam of charged particles in the conducting walls of a vacuum chamber. The transducer is designed for measuring the position of the centre of gravity of the beam and the ellipticity of its cross section. The transducer design is given. The transducer signal rise time is better than 0.3 ns

[en] A sensor which is based upon measurements of distribution of ''image current'' induced by a charged particle beam in conducting walls of a vacuum chamber is described. The operational version of the sensor comprises 16 monitors which are actually current transformers with signal wires as the primary winding. The secondary winding is loaded upon coaxial cables with 50 Ohm wave resistance. In case of 1:10 transformation ratio the total resistance introduced into the chamber discontinuity is 3.1x10xH-² Ohm, which ensures spreading time of about 100 ns. Sensor rise time is better than 0.3 ns. Apart from information upon the beam gravity centre the signals obtained from the sensor contain data on ellipticity of its cross section. A practical design of the sensor has been presented

No abstract available

[en] It is shown that if the pickup electrodes measuring the beam position are outside a dielectric vacuum chamber the effect of the chamber reduces to the appearance of scale factors for each of the beam-potential harmonics. Analytical expressions for the factors, which depend on the dielectric element geometry, its dielectric constant, and the number of the potential harmonic, have been obtained for the case of axially symmetric pickup electrodes and chamber

[en] Principles for construction of the system for stabilization of the proton beam radial position in the B-5 synchrotron are considered. Stabilization of the beam radial position during acceleration is performed by correction of the driving oscillator frequency according to the signals of the sign of beam excursion from vacuum chamber center. The stability of trimming loop is provided by the beam phase feedback. The expressions, relating the system parameters with beam characteristics are given. The above principles were used for construction of the system for stabilization of radial beam position in the B-5 synchrotron. The beam acceleration practically without losses is due to the operation of this system. When the number of beam particles doesn't exceed 1.5x10⁸, the system stabilizes its position in the limits of less than +-3 mm With respect to geometric center of the chamber, which constitutes 10% of its aperture

No abstract available

[en] The automated system for electron and positron beam trajectory stabilization booster storage unit into the VEPP-4 storage track is described. The above system includes the transducers for the beam parameter taking off and processing and the control computer. Special attention is paid to the beam positron transducer structure, which is used as the image current transducer. The achieved accuracy of coordinate resolution for transducers within the 4-150 range at the VEPP-3 equals 0.25 mm. 4 refs

[en] The status of the experiment on the precise τ lepton mass measurement running at the VEPP-4M collider with the KEDR detector is reported. The mass value is evaluated from the τ⁺τ^- cross section behaviour around the production threshold. The preliminary result based on 6.7 pb^-1 of data is m_τ=1776.80_-0.23^+0.25±0.15 MeV. Using 0.8 pb^-1 of data collected at the ψ^' peak the preliminary result is also obtained: Γ_ee.B_ττ(ψ^')=7.2±2.1 eV

[en] The first lasing near wavelength 140 μm was achieved in April 2003 on a high-power free electron laser (FEL) constructed at the Siberian Center for Photochemical Research. In this paper, we briefly describe the design of FEL driven by an accelerator-recuperator. Characteristics of the electron beam and terahertz laser radiation, obtained at the first experiments, are also presented in the paper

[en] The National Synchrotron Light Source II is a third generation light source under construction at Brookhaven National Laboratory. The project includes a highly optimized 3 GeV electron storage ring, linac pre-injector and full-energy booster-synchrotron. Budker Institute of Nuclear Physics builds booster for NSLS-II. The booster should accelerate the electron beam continuously and reliably from minimal 170 MeV injection energy to maximal energy of 3.15 GeV and average beam current of 20 mA. The booster shall be capable of multi-bunch and single bunch operation. This paper summarizes the status of NSLS-II booster.