Selection of High-Frequency Relays

The impedance of contacts of relays used as automatic switches in high-frequency (1–10 MHz) dielcometer analyzers was measured. The results of experimental investigations for six types of commercially produced relays are described. The use of a 12 high-frequency relay with an active resistance of closed contacts of one-fifth of that for 55 relay makes it possible to decrease an error component in the dielcometer control over substance compositions with a large and variable conductivity.     

The ВД-12НФП Eddy-Current Flaw Detector and Methods for Processing a Measured Signal Produced by a Flaw

The field of application, the features of operation, and the main performance characteristics of a -12 eddy-current flaw detector are considered. Methods of digital data processing for improving the recognition of flaw-produced signals against the background noise are presented.     

The ТЛ-1МП Thickness Meter for Galvanic Coatings

The specifics for monitoring the thickness of electrically- conductive coatings on a conductive substrate are described. Difficulties involved in designing thickness meters that assist in this task are noted. The technical characteristics and design of a -1 versatile eddy-current sensor are presented.     

Single-Electron Characteristics of a ФЭУ-184U Photomultiplier Tube

Single-electron and time characteristics of a -184U photomultiplier tube with a uviol window are presented. The -184U single-electron resolution can reach a value of 63–64%, and, in case of single-electron light-striking of the photocathode, the photoelectron transit time distribution (full width at half maximum) is 6 ns.     

A Combination β–γ-Radiometer and Dose-Rate Meter with an Extended Dynamic Range

A MKC-07 –-radiometer and dose-rate meter based on Geiger–Muller tubes is described. By using an unconventional signal-processing method, it is possible to extend the dynamic range of the instrument by a factor of 10–50, depending on the type and number of detectors in use, and to significantly reduce the error in measuring time-dependent ionizing-radiation intensities. The combination radiometer and dose-rate meter is used to determine the characteristics of constant and nonstationary ionizing-radiation fields.     

A Magnetometer Based on a Hall Probe

A magnetometer based on a 606117 Hall probe with residual field compensation and a sensitivity threshold of 10^–8 T Hz^–1/2 is described. A four-step algorithm of the residual field compensation is suggested. The algorithm allows the residual voltage to be reduced by a factor of 1200 and more. The magnetometer makes use of the analog switches series 590 and 1014.     

A Unit for Microwave Investigations of High-Temperature Superconductivity in a Magnetic Field

A simple updating of an P 1306 spectrometer for microwave absorption measurements in a low-induction magnetic field at temperatures of down to 15 K is described.     

A novel representation of tandem systems with inter-stage storage applied to on-line system monitoring

One of the goals of operating a tandem manufacturing system with finite inter-stage storage and asynchronous operations is to meet the demand without over-producing, under-producing or carrying large quantities of material in storage. We believe that analysing the operation of such a system on a real-time basis helps achieve this goal. The first step in this real-time analysis would be to quantitatively associate the causes and effects of over-production or under-production as they occur. This requires determining the cumulative effect that the performance that any stage has on the system, based on its history, the current system state and the interrelationships between the stages. This paper proposes a method which first represents uniquely and completely each stage and surrounding storage as an element. While this system, which consists only of this simple type of element functions in exactly the same way as the original one, each element is put into an ideal world for decoupled measurement. Though an element behaves in exactly the same way whether it is in the ideal world or in the real world, the elapsed times in the two worlds since the beginning of production can be different, since the responses (occurrences and durations of the blockings and starvations) of the two worlds can be different. A phase parameter is introduced for each element to represent this difference. Once the formation of the phase parameter of the output element is formulated, quantitative relationships between causes and effects of over-producing or under-producing can be explained as they occur.     

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.     

Error Corrections in a Sampling Sliding Along a Pulse Envelope Based on Decoding Tables

Code combinations of 2 ⁿ symbols +1 and –1 suggested for identification of characteristic features leading edge, trailing edge, maximum, minimum, horizontal portion, start of leading edge, end of leading edge, start of trailing edge, and end of trailing edge in a binary-code envelope of a pulse measured by an eddy-current transducer (ECT) scanning a tested surface generate a group code. This group code ensures for four levels of noise immunity the maximal likelihood in identification of reference sequences distorted by noise. The structure of a product code, which is also generated by the reference fragments, results in a higher capability of correcting for errors in moving samplings of signal envelopes, in particular, it reduces the degree of uncertainty in identification of the most important features of ECT pulses. The paper suggests simple decoding algorithms and regular logical structures that provide a high efficiency of the procedure eliminating errors in binary sequences of coded envelopes.     

Measurements of the Thermal Diffusivity and Thermal Conductivity of Metals Near the Melting Point

A pulsed technique for measuring the thermal diffusivity a and thermal conductivity of spherical samples with an allowance for the spatial–time energy distribution over the laser-beam cross section is described. The measured temperature dependences () and () for solid and liquid tin near the melting point of samples are presented. The a and measurement accuracies are 5 and 15%, respectively.     

Synthesis of Nanocrystalline Thin GaAs Films

A thermal method for the synthesis of nanocrystalline GaAs films is developed on the basis of a modernized -71-3 vacuum setup with three types of evaporators.     

Automated Devices for the Testing of Mill Rolls

Multichannel -type devices developed at TsNIITMASh for the automated ultrasonic inspection of cylindrical objects, such as mill rolls, shafts of turbines and compressor units, circular welded joints of thick-walled shell rings, etc., are described. These devices feature from two to eight acoustoelectronic channels. Acoustic contact occurs through industrial water. The testing is performed under workshop conditions; the object being inspected is rotated by a turning lathe or any other handling mechanism. Sonication is simultaneously performed by piezoelectric transducers (PETs) with input angles of 0, 40, 50, 60, and 70° and also by surface and head waves in order to reveal surface and subsurface flaws. A wide-span eddy-current transducer of special design is also used for this purpose. All data are stored in flash memory and retrieved on a PC located in an office. The inspection results are displayed as C- and B-type scanning defectograms. Moreover, it is possible to obtain an isometric image of flaw zones. -type devices have been used for over one and a half years in two workshops at OAO Severstal'.     

Electric Recording with a Double-Focusing Laser Mass Spectrometer

To improve the operating characteristics of an MA-2 double-focusing laser mass spectrometer or similar ones, a complex for electric recording of ion currents is developed, which allows one to conduct an elemental analysis in the online mode.     

Portable Electromagnetic-Acoustic Thickness Meters (EMAT)

Two varieties of contactless electromagnetic-acoustic portable thickness meters with autonomous power supply, created on the basis of up-to-date digital technologies, are described. The instruments implement a new highly efficient design of magnetic field concentrator developed on the basis of new magnetic materials. The -- thickness meter is equipped with a powerful microprocessor-based data processing system, which expands the capabilities of the instrument. The -100 thickness meter is a small-size and small-weight instrument. The main advantage of both instruments is that they can be operated on corroded untreated surfaces without the use of a contact fluid. Both instruments are suitable for testing through coatings of considerable thickness (up to 2 mm) and can be operated under workshop and field conditions.     

32-Channel All-in-One CAMAC Module as a Basic Element of Anode Wire Read-out Systems for Proportional Chambers

A special feature of the system is the integration of the amplifying section, signal delay unit, and digital section for the data outputting to computer into a common -32 module (CAMAC). The 1-M-size -32 module contains the electronics for 32 wires, which makes it possible to place up to 672 data channels in the CAMAC crate with a standard bus. To amplify signals, Ampl 8.3 eight-channel microcircuits are used. The output logic signals are delayed by 9-channel IDT72421 FIFO microcircuits enabling us to obtain a total signal delay of up to hundreds of microseconds and longer. The digital section of the system is based on ALTERA programmable logic arrays. At present, this system with a total of 576-channels is used in the PIBETA experiment to study rare pion decays on the PSI accelerator (Switzerland).     

The Magnetometric System of the СПРУТ-VI Instrument Package

The magnetometric system of the -VI instrument package installed on board the Mir orbital station in 1999 is described. The system was a fluxgate magnetometer that enabled high-precwasion vector measurements (with a resolution of 0.1 nT for each component) of the magnetic field over a range of ±65000 nT. The operating temperature range of the sensing device was –170 to +80°C and the temperature range of the system electronics was –55 to +60°C. The system was used for studying fluctuations of the Earth's magnetic field and characteristics of various particle formations in near-equatorial and low latitudes as well as calculating the pitch-angle distribution of fluxes of charged particles and determining the exact spatial coordinates of isolated malfunctions in microcircuits.     

Identification of Characteristic Features of Envelopes of Testing Pulses with the Help of the Diade Convolution Adaptable to Noise Level: I. Identification of Types of Characteristic Features

A method has been suggested for binary coding of envelopes of measured pulses from eddy-current transducers. The method enables one to identify their characteristic features of various types, such as leading edge, trailing edge, maximum, minimum, horizontal portion, start point of leading edge, end point of leading edge, start point of trailing edge, and end point of trailing edge, using weighted sums of no more than four Hadamard-ordered Walsh functions with numbers 0, 1, 2 ^n–1, and 2 ^n–1 + 1. The paper demonstrates the existence of obvious diade correlations of coded combinations corresponding to specific fragments with both one another and distortions of a current sampling simulated by adding an error vector. These properties make possible an identification of types of characteristic features in current samplings of binary data with four levels of a noise immunity, which are selected in the process of adaptation to the noise intensity with due account of the significance of identified features.     

Measurement of the Background Level in the Spectra of Internal-Conversion Electrons Using the МАС-1 Microscope Complex

A method for measuring the spectral lines in an -50 photoemulsion plate with a varying background level is described. The -ray spectrograph of the Joint Institute for Nuclear Research's Laboratory of Nuclear Problems, was used to record the spectra. The plate was exposed to internal-conversion electrons produced by the decay of erbium isotopes (erbium fraction). The spectral measurements were performed using the -1 microscope complex. The distribution of the background level over the plate surface was measured. Using the L-structure of the -ray line of ¹⁶¹Ho with an energy of 175.5 keV as an example, it was shown that the accuracy of the intensity measurements was 10% or better. The accuracy in measuring the background level governed the accuracy in identifying the multipolarity of nuclear transitions. A precision TV system for data readout based on a 768 × 576 pixel CCD matrix provided a measurement accuracy of 0.5 m for both coordinates.     

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.