An Electromagnetic Calorimeter with a Transversal Orientation of the Scintillating Fibers

The space and energy resolutions of the SPACAL electromagnetic calorimeter with a transverse orientation of the scintillating fibers have been measured. The main parameters of the calorimeter are presented. The results of experiments with an electron test beam of the DESY synchrotron at energies E = 1–6 GeV are discussed. The measured energy resolution of the calorimeter is found to be (/E) = 12.7%/E 2.0% (E is expressed in terms of GeV), and the space resolution is _{x, y} (E) = 1 mm at E = 4 GeV.     

The possibility of measuring the qualitative parameters of welded gears

The problem of measuring weld penetration during electron-beam welding by an ultrasonic method is considered. The results of calculations and data of experimental studies are reported. The efficiency of introducing the ultrasonic method for testing weld penetration during electron-beam welding is demonstrated.Translated from Defektoskopiya, Vol. 41, No. 1, 2005, pp. 29–31.Original Russian Text Copyright © 2005 by Sadadinov, Pyankov.     

The PIBETA spectrometer for studying rare and forbidden decays of muons and pions

The construction and characteristics of the PIBETA spectrometer are described. This spectrometer is designed to implement a program of precise measurement of pion decay ^{+ 0} + e ⁺ + _e at the Paul Scherrer Institute (Switzerland). A spherical calorimeter, consisting of 240 crystals of pure CsI scintillator and embracing a solid angle of 3, is the main detector of the setup. In addition, the spectrometer is composed of an active collimator (which also acts as a beam degrader), a segmented active plastic target, two multiwire cylindrical proportional chambers, a 20-element cylindrical plastic hodoscope, and veto counters of cosmic muons.__________Translated from Pribory i Tekhnika Eksperimenta, No. 2, 2005, pp. 39–48.Original Russian Text Copyright © 2005 by Baranov, Kalinnikov, Karpukhin, Khomutov, A. Korenchenko, S. Korenchenko, Kravchuk, Kuchinskii, Mzhaviya, Rozhdestvenskii, Sidorkin, Tsamalaidze, Sakhelashvili, Frlez, Poanic, Li, Minehart, Smith, Stephens, Ziock, Bertl, Horisberger, Ritt, Schnyder, Wirtz, Ritchie, Supek, Kozlowski.     

The full-voltage effect and the optimal modes of the pulsed conditioning of electrodes in a vacuum

The effect of full voltage on the efficiency of the pulsed conditioning of electrodes in a vacuum is assessed. The efficiency of optimal conditioning modes, estimated from the quality of the cathode surface relative to gaps of centimeter length and long-acting voltage, increases by more than two orders of magnitude when the pulse duration and interelectrode gap are reduced. An increase of up to one order of magnitude is achieved by reducing the gap width to micron sizes during conditioning. The efficiency increases by a factor of as much as 30 by reducing the pulse duration and raising the optimal regimes pulse power.__________Translated from Pribory i Tekhnika Eksperimenta, No. 2, 2005, pp. 92–94.Original Russian Text Copyright © 2005 by Emelyanov, Emelyanova, Kubyshkina.     

Structural synthesis of attachable eddy-current probes with a given distribution of the probing field in the test zone

A method for designing attachable eddy-current probes with a given spatial distribution of the probing field is proposed. This method is based on a structural synthesis implemented using a genetic algorithm. An example of the numerical solution for the synthesis of a local cylindrical probe is given.Translated from Defektoskopiya, Vol. 41, No. 1, 2005, pp. 40–46.Original Russian Text Copyright © 2005 by Galchenko, Vorobev.     

A high-speed precision digital phase meter with direct calculation of the signal phase

A programmed phase meter for the detection of small phase deviations is described. The device is designed for a remote vibration meter. The application of digital signal processing ensures the detection of differential or simple phase deviations at a specified carrier frequency of 10.7 MHz with a sensitivity of 10^–5 rad.__________Translated from Pribory i Tekhnika Eksperimenta, No. 2, 2005, pp. 88–91.Original Russian Text Copyright © 2005 by Goncharenko.     

Synchronization of a millimeter-band oscillator on an avalanche-transit diode

Experimental results from investigations of the synchronization band of an 8-mm-band oscillator on an avalanche-transit diode are given. The dependencies of the synchronization band on the parameters of the generators oscillating system and the supply current of the avalanche-transit diode are presented.__________Translated from Pribory i Tekhnika Eksperimenta, No. 2, 2005, pp. 101–102.Original Russian Text Copyright © 2005 by Alekseev, Maliev, Nashchanskii.     

A three-coordinate electromagnetic stepping system for positioning the tip of a scanning tunneling microscope

A simple, compact device for stepwise three-coordinate translation, designed to position the tip of a scanning tunneling microscope operating at liquid-helium temperatures, is described. Movement is effected by the forces of interaction between the currents in a system of coils through which current pulses of up to 10 A and a duration of 20–200 µs are passed. The range of translations along all coordinates is several millimeters, and the size of the controllably varied step ranges from 0.1 to several tens of microns. The voltage applied to the motor elements is <100 V, excluding the possibility of an electric breakdown during operation in gaseous helium at any pressure.__________Translated from Pribory i Tekhnika Eksperimenta, No. 2, 2005, pp. 133–139.Original Russian Text Copyright © 2005 by Ofitserov, Edelman.     

A device for measuring the angular distribution of the output radiation of optical fibers

The characteristics of a device developed for measuring the angular distribution of the intensity of the output radiation of optical fibers in the far field are described. The devices angular translation stage is controlled through a standard parallel port of a personal computer, and the experimental data are acquired and digitized using a standard sound card. The dynamic range of measurements is >50 dB. Examples of measurements performed with this device for single-mode optical fibers of several types are presented. Good agreement between the calculated and experimental data is demonstrated. The effect of the dynamic range of measurements in the far field on the accuracy of calculating the mode field distribution was investigated.Translated from Pribory i Tekhnika Eksperimenta, No. 1, 2005, pp. 112–118.Original Russian Text Copyright © 2004 by Grekov, Vasilev, Korolev, Bozhkov, Medvedkov, Senatorov.     

A Coordinate Detector for Studying Horizontal Fluxes of Cosmic Rays

A DECOR coordinate detector is a multilayer system of plastic streamer tube chambers located around a NEVOD Cerenkov water calorimeter. The basic characteristics of the detector are as follows: the area is 100 m², the angular resolution is 1°, and the space resolution is 1 cm. The structure of the detector, data acquisition and trigger systems, and results obtained during the operation of a pilot assembly (8 chamber layers and a working area of 8.4 m²) are given.     

The adsorption of zinc dialkyldithiophosphates on partially stabilized zirconia from hydrocarbon solution

Kinetics, isotherms and enthalpy of adsorption of zinc di-n-alkyl(di-n-alkylphenyl, di-n-dialkylphenyl)dithiophosphates (ZDTPs) lubricating oil additives on zirconia partially stabilized by yttria (PSZ) powder from hydrocarbon solution at temperatures 25 °C and 35 °C were done. The adsorption enthalpy has been determined using a Montcal calorimeter. ZDTP adsorption isotherms are Langmuir-like. The adsorption quantities and differential molar enthalpies of ZDTPs adsorption on PSZ are low for n-alkyl derivatives, the adsorption decreases with the increasing length of the hydrocarbon chain of the additive ZDTP, the unexpectedly for di-n-propyl ZDTP the differential molar enthalpies of adsorption at 25 °C are very low, near zero and for di-n-dialkylphenyl ZDTP only at lower coverage ratios are endothermic, at higher surface coverage for this and remaining additives are exothermic. At 35 °C all n-alkyl ZDTPs adsorb on PSZ endothermically endothermic, while both aryl ZDTPs exhibit exothermic effects. All ZDTPs are reversibly physisorbed at 25 °C and at 35 °C except for both mono- and dialkylphenyl ZDTPs, which are weakly chemisorbed.     

The use of generalized magnetic parameters for magnetic structural analysis and nondestructive testing

The results of studies regarding the dependence of the product of the coercive force and the initial magnetic susceptibility of a nickel single crystal with an intermediate orientation on the shear stress are analyzed. It is concluded that an increase in the aforementioned product for a nickel single crystal upon cold plastic deformation is due to refining of magnetic domains that is caused by formation of cells and subgrains within the single crystal. The tentative size of magnetic domains was determined based on the value of generalized magnetic parameter . The variations in the product and in the calculated dimensions of magnetic domains in polycrystalline nickel are analyzed using data reported by Kersten-Gottschalt. It was also shown that, the density of dislocations being constant, the generalized magnetic parameter is sensitive to changes in the sizes of nonferromagnetic inclusions, whereas in the case of small nonferromagnetic inclusions, an increase in the generalized parameter is due to an increase in the density of dislocations.Translated from Defektoskopiya, Vol. 40, No. 7, 2004, pp. 62–76.Original Russian Text Copyright © 2004 by Bida.     

Facility for investigating the propagation of sound in the surface layer of the earth’s atmosphere

The facility is intended for investigating the propagation of sound waves in the surface layer of the Earths atmosphere. It permits the directional radiation, and recording, of high-level audio-frequency sound. The maximum sound level (referred to a distance of 1 m) is as high as 151 dB; the antenna beamwidth is 6° to 16°, depending on the frequency; the side-lobe level does not exceed –20 dB; and the lengths of the investigated propagation paths, with various underlying surfaces, are up to 3 km.__________Translated from Pribory i Tekhnika Eksperimenta, No. 2, 2005, pp. 130–132.Original Russian Text Copyright © 2005 by Krasnenko, Kudryavtsev, Mananko.     

A microwave interferometer for steady-state plasma density measurements

An interferometer for a wavelength of 8 mm, capable of homodyne frequency conversion for measuring the electron density of a steady-state plasma from a high-frequency ion source, is described. An original method for generating a reference intermediate-frequency signal using a cavity resonator is applied in the interferometer. The unambiguously measured phase shifts range from 1.5° to 360°, and the error in measuring the phase shift is 5%.__________Translated from Pribory i Tekhnika Eksperimenta, No. 2, 2005, pp. 98–100.Original Russian Text Copyright © 2005 by D. Nagornyi, A. Nagornyi, Voznyi.     

Processing an array of data on radiation testing of content of the main material and longitudinal distribution in rod-type specimens

Additional processing of the data array obtained from scanning a specimen by a radiation-data converter is proposed. This approach makes it possible to improve the accuracy with which dimensions and locations of characteristic zones are determined in rod-type specimens. The procedure involves binary coding of the moving-average function and restoring the arrays envelope by comparing a fixed-length sample, which moves along the binary array, to standard samples during preliminary conversion of samples into codes-products.Translated from Defektoskopiya, Vol. 40, No. 12, 2004, pp. 30–39.Original Russian Text Copyright © 2004 by Mushnikov.This revised version was published online in April 2005 with a corrected cover date.     

Studying the Kinetics of Radiation Damage in PWO Crystals for the CMS Electromagnetic Calorimeter (CERN)

The influence of the irradiation of PWO crystals on the characteristic timing parameters of changes in their optical transparency and subsequent recovery during the working cycle of the LHC accelerator (CERN) was studied. PWO crystals were irradiated with a working dose corresponding to the radiation load in the electromagnetic calorimeter. A method for evaluating the influence of the change in the optical transparency of scintillation crystals on the statistical term in the energy resolution of the electromagnetic calorimeter in intense radiation fields is proposed. This method is applied to the development of the technology of mass production of radiation-hard scintillation crystals used in electromagnetic calorimetry and to its certification.__________Translated from Pribory i Tekhnika Eksperimenta, No. 3, 2005, pp. 37–41.Original Russian Text Copyright © 2005 by Dormenev, Drobyshev, Korzhik, Lopatik, Peigneux, Sillou.     

Upgrade of the beam profile ionization monitor for the KOMBAS fragment separator

The results from upgrade of an ionization beam profile monitor (IBPM) are presented. The IBPM consists of a conventional capacitor that extracts the ionization products of the residual gas and analyzing capacitors. The main objective of this upgrade was to create a device with uniform spatial resolution. For this purpose, an additional difference of potentials, the ramping of which allows the beam cross section to be scanned, is applied between the capacitors of the monitor, while the electric fields in the capacitors themselves remain constant. Two IBPMs have been developed as a result of the facilitys upgrade: an IBPM for on-line monitoring of the vertical and horizontal beam current distributions in the beam line in an area of 8 × 8 cm² with a uniform 1-mm resolution, and an IBMP for detailed beam profile monitoring with a uniform resolution of 1 × 1 mm² over the scanning region. It was established experimentally that the proposed scanning technique provides good results in beam profile measurements when the ion component of the ionized residual gas is extracted; for the electron component, the result is much worse.__________Translated from Pribory i Tekhnika Eksperimenta, No. 2, 2005, pp. 61–66.Original Russian Text Copyright © 2005 by Teterev, Phi Thanh Huong.     

Behavior of plutonium in floodplain soils

It is shown that the plutonium concentration in the floodplain soils of the Techa-Iset river system is 10–100 times higher than the level attributable to the global nuclear fallout and regularly decreases with distance from the source of contamination. As follows from the Pu-⁹⁰Sr and Pu-¹³⁷Cs ratios, the migratory ability of Pu is higher than the migratory ability of ¹³⁷Cs but lower than that of ⁹⁰Sr.Translated from Defektoskopiya, Vol. 41, No. 1, 2005, pp. 74–79.Original Russian Text Copyright © 2005 by Mikhailovskaya, Molchanova, Karavaeva.     

The DEVIS track detector developed by the Institute for Theoretical and Experimental Physics for studying double β decay

The DEVIS setup, consisting of a time projection chamber placed in a magnetic field, is designed to study the 2 decay of ¹³⁶Xe atoms. The sensitivity of the setup was assessed in a set of measurements using Xe with natural isotopic composition. The setup will allow observations of the two-neutrino double decay of ¹³⁶Xe with a half-life of <3 × 10²⁰ yr.__________Translated from Pribory i Tekhnika Eksperimenta, No. 2, 2005, pp. 49–60.Original Russian Text Copyright © 2005 by Artemiev, Belov, Brakhman, Zeldovich, Karelin, Kirichenko, Kozodaeva, Kuchenkov, Lyubimov, Mitin, Tsvetkova.     

A two-coordinate detector for a beam of atomic hydrogen or deuterium

The profile of an atomic beam in the region where it forms is an important characteristic of a polarized atomic hydrogen (or deuterium) source. A mathematical model for a two-coordinate resistive detector of atomic hydrogen beams is presented. Metering equipment and a technique for measuring an atomic beam profile are described, and the results of our measurements are presented.Translated from Pribory i Tekhnika Eksperimenta, No. 1, 2005, pp. 141–145.Original Russian Text Copyright © 2004 by Trofimov, Vasilev, Kovalev, Kravtsov.