Capacitive Discharge Excilamps

UV radiating sources on KrCl ( 222 nm), XeCl ( 308 nm), and XeBr ( 282 nm) molecules excited by a capacitive discharge are described. The sources have a simple design of the radiator and are characterized by a high radiation efficiency (up to 25%), a lifetime of up to 2500 h, and a radiation band half-width of 4–8 nm.     

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'.     

A Switching System for Capacitive Energy Storage

The system is intended both for synchronous and programmed discharging of large capacitive energy storage systems. As circuit closers, triggered vacuum switches (TVSs) -43 are used. The TVSs can handle a current of up to 200 kA at a voltage of up to 30 kV and charge of up to 120 C. Each TVS is enclosed in a shielding case with sockets for coaxial cables that connect the switch with the capacitors and the load. Switch-triggering pulses are generated by multichannel high-voltage pulse generators (triggering generators). Each channel is controlled by a programmer via a fiber-optic cable. The programmer operates in conjunction with a computer and provides, in each channel, a prescribed delay of the pulses generated relative to the synchronizing pulse common to the entire system.     

An Infrared Camera Based on Schottky Barriers for Daytime Observations of Stars

The daytime-sky background spectrum is analyzed. It is shown that the spectrum has a minimum in the vicinity of 2.5 m, which is close to the position of the peak of the spectral characteristic of elements of an array based on PtSi Schottky barriers. The optical layout of an -26 telescope with a built-in IR camera and an alignment channel is presented. The technique of adjusting the IR camera as a part of the telescope is described. The threshold sensitivity of the system, which consisted of the telescope with a 600-mm-diameter lens and an IR camera based on PtSi Schottky barriers, was experimentally measured in the spectral region of 1.2–3.3 m and was found to be equal to three stellar magnitudes.     

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 High-Voltage Switching Device Based on Two High-Current Vacuum Gaps Connected in Series

A high-voltage switch that consists of two -43 triggered vacuum spark gaps connected in series has been manufactured and tested. The switch is intended for use at a voltage of up to 80 kV. The maximum current switched is 200 kA. The breakdown strength of the switch has been theoretically and experimentally investigated. Experimental and theoretical breakdown-voltage distribution functions have been obtained for the gaps and the switch. Based on the empirical breakdown-voltage distributions for both of the gaps, the breakdown-voltage distribution for the switch has been calculated and found to be in satisfactory agreement with the measurement results.     

A 14-Bit Code-to-Current Converter

A high-precision code-to-current converter ensuring a conversion error corresponding to 14 bits is described. The output current of the converter is ±250 mA, and the conversion nonlinearity is 0.015%. The converter circuit has insignificant time (0.001%/h) and temperature (0.001%/10°) drifts. The suppression of supply voltage variations is 70 dB.     

A Modern Solution to Problems of Eddy-Current Structuroscopy

The problems arising during nondestructive quality tests of articles of nonmagnetic alloys and during sorting in the electrical conductivity are considered. The function and performance characteristics of a -26 eddy-current structruroscope are described. The structural diagram of this device and the algorithm of its operation are described. The capabilities of the -26 eddy-current structruroscope for performing nondestructive quality tests of thermal treatment of articles made of nonmagnetic materials are analyzed.     

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.     

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.     

A High-speed Charger of a Five-megavolt Shaper of Nanosecond Voltage Pulses

A generator of voltage pulses with an amplitude of up to 4.5 MV is described. The generator is a part of an oil-filled shaping line (in the following, called shaper) and enables a high-speed (in 0.5 s) charging of a coaxial line up to a voltage of 5 MV in order to decrease (by a factor of 2–3) the duration of the leading edge of the generated nanosecond voltage pulse. The circuit and design solutions that enable a very low specific self-inductance of the discharge circuit, 3.35 H/MV, are presented. The -4.5 generator has a rated voltage of 4.5 MV, discharge capacitance of 16 nF, stored energy of 162.0 kJ, self-inductance of 25.0 H, and a probability of no failure of 0.9987.     

Assessment of the Hazard Level (Depth) of Flaws Using a ВД-12НФМ Eddy Current Flaw Detector

The operation features and the main technical characteristics of the -12 eddy current flaw detector are considered. A method is proposed for testing complex-shaped parts with the use of holding attachments and a specialized transducer with a slanted sensitive element. The capabilities of the device in assessing the hazard level (depth) of a flaw are shown. The distinctive features of the -12 eddy current flaw detector are presented.     

The Materials Science Complex of the СПРУТ-VI Instrument Package

The materials science complex of the -VI instrument package developed for the Mir space station was designed for studying the effect of factors of outer space and space flight conditions on various construction components. The complex was used to expose materials in both passive and active modes (to obtain current–voltage characteristics of various photoelectric converters of solar batteries) and to assess the isolated-error rate in integrated circuits (IC) under space-flight conditions with the simultaneous monitoring of the radiation environment. The verification of various engineering solutions was also included in the materials science program.     

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.     

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.     

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.     

Generation of High-Voltage Subnanosecond Pulses with a Peak Power of 700 MW and Repetition Frequency of Up to 3.5 kHz

Test results of a combined subnanosecond modulator with an output impedance of 45 , which incorporates an all-solid-state high-voltage nanosecond charging device (with an inductive energy storage and a semiconductor opening switch) and a pulse sharpener with gas-filled gaps, are presented. The sharpening and cutting spark gaps filled with hydrogen at a pressure of 100 atm ensured the formation of stable pulses with amplitudes of –(180–200) kV and durations of (400–700) ps at a repetition frequency of up to 3.5 kHz. An average output power of 1.4 kW was achieved for the modulator's burst-mode operation with a number of pulses in a packet of 10⁴at a maximum pulse repetition rate.     

A Plasma Source for a Microsecond Plasma Opening Switch

The results of the studies of surface plasma sources with an -7 optical photochronograph and a double electric probe are presented. The designs of radial and axial plasma generators are described. It is shown that a radial SPS does not ensure satisfactory reproducibility of the plasma flow parameters from pulse to pulse, which influences the operation stability of plasma opening switches. Based on data obtained experimentally, a modernized axial plasma generator was constructed. Studies of plasma flows with a double electric probe have shown that, at equal energy contributions to the plasma generator, the probe's current density increases by a factor of four. The use of an axial surface plasma source on the SIGNAL (high-current pulse generator for laser pumping) installation with a plasma opening switch resulted in the front sharpening of the load current pulse (200–220 kA) from 60 ns obtained in earlier experiments to 30 ns for the same current amplitude.     

On reconstruction of cracks with interacting edges

A method for the reconstruction of the configuration of cracks is suggested based on finding heat sources that model the interaction between cracks edges (such as friction and collapse) in solids exposed to external ultrasound. The input information for reconstruction is a stationary temperature field on a solid boundary. The functional of nonreciprocity was constructed; the study of this functional made it possible to convert the problem of determining a cracks parameters into a few transcendental equations; explicit formulas were obtained for small cracks. The results of computational experiments on reconstruction of the parameters of a straight crack are considered.Translated from Defektoskopiya, Vol. 40, No. 10, 2004, pp. 62–69.Original Russian Text Copyright © 2004 by Vatulyan, Solovev.     

Formation of High-Power Pulses of Nanosecond Duration by Generators on Reverse Switch-on Dynistors with Sharpening Circuits Based on Diode Opening Switches

The basic principles of constructing generators of nanosecond pulses on reverse switch-on dynistors with sharpening output circuits based on diode opening switches are considered. The results of an experimental study of a high-power generator incorporating such a dynistor; a step-up pulse transformer; and a high-voltage diode opening switch, which is an assembly of drift step-recovery diodes connected in series, are presented. The output voltage pulses of the generator with an amplitude of 45 kV, a duration of 50 ns, a rise time of 10 ns, and a repetition rate of 1 kHz are applied to a load resistance of 25 .