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  • 1
    Electronic Resource
    Electronic Resource
    Study of Δ(1232) isobar electroproduction at the VEPP-2M e + e − collider (1998)
    Springer
    JETP letters 67 (1998), S. 777-780 
    Details
    ISSN: 1090-6487
    Keywords: 25.30.Rw ; 14.20.Gk ; 13.65.+i
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Results from the Spherical Nonmagnetic Detector (SND) on Δ(1232) isobar electroproduction in the collisions of beam electrons (positrons) and residual gas nuclei in the VEPP-2M e + e − collider are presented. On the basis of the data obtained the expected counting rate of this process in future high-luminosity e + e − colliders (φ, c-τ, and b factories) is estimated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.567747
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  • 2
    Electronic Resource
    Electronic Resource
    The process e + e − → ωπ0 near the Φ resonance (2000)
    Springer
    Journal of experimental and theoretical physics 90 (2000), S. 927-938 
    Details
    ISSN: 1090-6509
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The reaction e + e −→ωπ0 near a Φ resonance was studied with a spherical neutral detector at VEPP-2M e + e − collider. Both main modes of decay of a ω meson were investigated: ω→π+π−π0 and ω→π 0γ. The probability of decay Φ→ωπ0 was obtained from the magnitude of the interference wave in the cross section for the reaction e + e −→ωπ0→ π+π−π0π0: B(Φ→ωπ0) = (5.5 −1.4 +1.6 ±0.3) ×10−5. The ratio of the partial widths of the ω meson was obtained from the ratio of the cross sections for the two modes: Γ(ω→π0γ )/Γ(ω→π+π−π0) = 0.0994 ± 0.0036 ± 0.0038.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.559181
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  • 3
    Electronic Resource
    Electronic Resource
    Multiframe digitization of x-ray (TV) images (abstract) : INTERNATIONAL CONFERENCE ON SYNCHROTRON RADIATION INSTRUMENTATION (1989)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 60 (1989), S. 2335-2335 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The work in progress deals with the experimental search for a technique of digitizing x-ray TV images. The small volume of the buffer memory of the analog-to-digital (A/D) converter (ADC) we have previously used to detect TV signals made it necessary to digitize only one line at a time of the television raster and also to make use of gating to gain the video information contained in the whole frame. This paper is devoted to multiframe digitizing. The recorder of video signals comprises a broadband 8-bit A/D converter, a buffer memory having 128K words and a control circuit which forms a necessary sequence of advance pulses for the A/D converter and the memory relative to the input frame and line sync pulses (FSP and LSP). The device provides recording of video signals corresponding to one or a few frames following one after another, or to their fragments. The control circuit is responsible for the separation of the required fragment of the TV image. When loading the limit registers, the following input parameters of the control circuit are set: the skipping of a definite number of lines after the next FSP, the number of the lines of recording inside a fragment, the frequency of the information lines inside a fragment, the delay in the start of the ADC conversion relative to the arrival of the LSP, the length of the information section of a line, and the frequency of taking the readouts in a line. In addition, among the instructions given are the number of frames of recording and the frequency of their sequence. Thus, the A/D converter operates only inside a given fragment of the TV image. The information is introduced into the memory in sequence, fragment by fragment, without skipping and is then extracted as samples according to the addresses needed for representation in the required form, and processing. The video signal recorder governs the shortest time of the ADC conversion per point of 250 ns. As before, among the apparatus used were an image vidicon with luminophor conversion of x-radiation to light, and a single-crystal x-ray diffraction scheme necessary to form dynamic test objects from x-ray lines dispersed in space (the projections of the linear focus of an x-ray tube).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1140760
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  • 4
    Electronic Resource
    Electronic Resource
    Device for absolute calibration of x-ray imaging detectors and x-ray counters (abstract) : INTERNATIONAL CONFERENCE ON SYNCHROTRON RADIATION INSTRUMENTATION (1989)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 60 (1989), S. 2336-2336 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Electronic devices intended to visualize x-ray images are intensively evolved on the basis of linear video signal shapers (LVSS): x-ray vidicons, image vidicons with x radiation-to-light conversion using luminophors and scintillators, charge-coupled devices, photodiode arrays and matrices, as well as on the basis of various electro-optical converters: electrostatically or magnetically focused and microchannel image intensifers. Their broad application to x-ray diffraction topography, structue analysis, diffractometry, tomography, and radiography has necessitated (already from 1982) the introduction of a common criterion for calibration of their sensitivity—the flux density of monoenergetic photons. In particular, when calibrating the LVSS it is necessary to find a direct, unambiguous correspondence between this criterion and the amplitude of a video signal. For this purpose, a device has been designed which is used both for absolute calibration of LVSSs and, of course, for a trivial standardization of x-ray counters with respect to their efficiency. This device is based on two commercial gas proportional counters whose position in space is aligned for a successive, one after another, "threading'' of them to the x-ray beam monochromatized by means of the crystal-diffraction scheme (Lukirsky's method). Both counters are identical to each other. Of course, each counter has input and output windows. The beam is shaped by diaphragms and by two slits, horizontal and vertical, with cylinders as "knives.'' One of the slits is scanned in the diffraction plane by a stepper motor. The counters are tested for identity by selecting them depending on their counting properties and energy resolution, with the escape peaks taken into account. All these operations and the rest of the measurements are performed by electronic units in the CAMAC standard, controlled by a microcomputer. On the test monochromatized x-ray beam, the device is interchangeable with a LVSS or a counting detector being standardized. The test beam is monitored. The width of the slit being scanned is shaped up to 10 μm, thereby allowing the LVSS to be standardized for geometrical resolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1140761
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  • 5
    Electronic Resource
    Electronic Resource
    Parameters of a high-sensitive x-ray imaging detector on the basis of an electro-optical image intensifier and an image vidicon (abstract) : INTERNATIONAL CONFERENCE ON SYNCHROTRON RADIATION INSTRUMENTATION (1989)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 60 (1989), S. 2334-2334 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Since the early 1980s a tandem system consisting of an electrostatically focused image intensifier and an image vidicon has found extensive applications to visualization of the images formed by weak fluxes of x radiation. We present the result of measurements of some parameters of this complex linear video signal shaper (LVSS). The test x-ray image—x-ray lines dispersed in space by a single-crystal diffraction scheme (the projections of the linear focus of an x-ray tube) is directed onto a commercial one-stage image intensifier with electrostatic image focusing whose fiber-optics input window is covered by a luminophor to convert x radiation to light. The outlet of the image intensifier is fiber-optically coupled to the input fiber glass window of the commercial image vidicon (silicon intensifier target tube with intensifier section). The measurements performed on the device for absolute calibration of x-ray imaging detectors and x-ray counters (see the report at this Conference) have shown that the use of this LVSS permits one to record threshold flux densities of monoenergetic photons which are more than one order of magnitude lower than with the use of the image vidicon alone. Measurements of the dependence of the threshold flux density on the photon energy have been made. For example, for 8 keV (Cukα), when using gadolinium oxysulphide as the luminophor the threshold flux density is 20 times lower than for the image vidicon alone, and achieves 105 cm−2 s−1. At such a high sensitivity, detection of small-scale details of images with low brightness and contrast requires taking account of the noise of the radiation being detected, which is caused by the fluctuations of the photon flux. This LVSS visualizes light flashes caused by single hard x-ray photons and β particles which are incident upon the luminophor settled on the inlet window of the image intensifier. Both the x-ray images of the test objects and the luminescent flashes caused by photons and fast electrons are represented in digital form (see the report on multiframe digitization x-ray images at this Conference).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1140759
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