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[en] An algorithm for track search in the 6-meter spectrometer with electrodynamic chambers uniformly distributed in an analyzing magnet field is described. The algorithm takes into account the chamber design features and operates reliably in a wide range of measured particle momenta (0.3-40 GeV/c) and chamber efficiency (60-100%)

[en] Experimental data (∼ 40000 K_SK_S events and ∼ 2300 ΛΛ-bar events) were obtained on the ITEP 6-meter spectrometer with a 40 GeV π- beam of the IHEP U-70 accelerator. The experimental setup is being upgraded now. The analysis of the 1200-1300 MeV/c2 effective mass region of the K_SK_S-meson system was carried out for events obtained with the neutral trigger with 40 cm H2 target. Irregularity near 1240 MeV/c2 and width about 30 MeV/c2 is clearly observed. Similar irregularity is observed on another sample of 15000 event on carbon target. A resonance states with mass near 1800 MeV/c2 and 2230 MeV/c2 are observed at selection of cos θGJ. The results of studying the ΛΛ-bar system produced in the reaction π-p → ΛΛ-barn at a π--meson energy of 40 GeV are reported. The invariant-mass spectra for the events dominated by the singlet or triplet ΛΛ-bar states were found to differ considerably from each other. The data give evidence for the existence of resonance states of the ΛΛ-bar system in the mass regions near 2.3, 2.5 and 2.8 GeV

[en] A calculational model of a wire spark chamber with the electrodynamic data read-out is considered. The model was developed for providing a required accuracy of the point determnation on a track and takes account of geometric characteristics of each of 64 chambers of a magnetic spectrometer, sound duct material properties, mechanism of spark development and electronic un properties. The model permits to adequately describe tracks with an angle of up to 0.5 rad. between a tangent to the track and a normal to chamber electrodes. The requirement of periodical changing of direction of ultrasonic pulse propagation, which permits to determine the effect of a current pulse shape in sparks and delays of their development with respect to reference pulses is intro-- duced into the model. The model also permits to attain track coordinate mesurement accuracy better than 0.4 mm for 0.5-40 GeV/c particle pulses. This allows to determine particle pulse passing through all the spectrometer chambers with 0.5% accuracy and the effective mass of π⁺π^- meson track pairs of K⁰ decay with an error of an order of 10 MeV/c

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No abstract available

[en] The main parameters of magnetic 6-meter spectrometer, set at second particle beams of IHEP proton synchrotron, are considered. Determination algorithm of charged particle track parameters in spectrometer magnetic field is described. Spectrometer track detector is placed in 150x80 cm cross section electromagnet gap. Field induction nominal value in the gap centre is 1.9 T. Detector consists of 64 spark chambers with electrodynamic technique of information reading. A traditional method, based on numerical solution of two second-order differential equations system for charged particle trajectory in magnetic field and usage of least squares method when evaluating parameters and their errors, is used to determine particle track parameters. A new feature of the algorithm used is the introduction of supplementary parameter - spark cross driftage in crossing electric and magnetic fields. This new parameter characterizes track origination time in spectrometer relative to the start-up signal and is used to determine tracks unrelated to the event. The algorithm described is realized in computer codes for PDP-15, BESM-6 and ES 1060 computers. By their means ∼300 thousand of events have been processed. The data obtained give evidence of conducting calculations satisfactory accuracy

[en] A procedure for determining geometric reconstruction constants by the ITEP 6m magnetic spark spectrometer has been described. Geodesic measurements and the procedure described provide 0.3 m/m horizontal and 1.6 mm vertical accuracy of space reconstruction. The geodesic measurements are performed in two stages: chamber certification-measurement of point coordinates on mark filaments and soundguides in a system connected with two chamber marks (template system), conjunction to the spectrometer coordinate system-measurement of chamber mark coordinates in the working position of the chambers. The described method for determining constants is optimal, as it requires little time (approximately 2h) and can be used when necessary during each movement of the spectrometer chambers

No abstract available

[en] A Calorimetric-Time-Of-Flight (CTOF) technique is proposed for real-time, high precision measurement of neutrons spectrum, and for evaluation of charged particles spectra and parameters of gamma radiation. By using the CTOF technique, it is possible to make these measurements in framework of the single experiment. This technique consists of a set of current mode time-of-flight instruments each having a set of organic scintillation detector placed at a different distance from a source at an interested angle from the initial proton beam direction. The CTOF technique is applicable to burst source conditions with radiation pulse duration of some dozens of nanoseconds and intensity of the order of 10¹⁰-10¹² particles per pulse. In experiment, a cylindrical tungsten target of 20 cm in diameter, 22.5 cm thick, was irradiated with 50 ns width, 1.2 and 0.5 GeV proton pulses of 2.5x10¹¹ ppp. One-litre scintillators followed with 120 m long light-guides and photomultipliers were used for determining neutron and proton spectra and gamma rays flux intensity at the angle 175 degree sign from the initial proton beam direction. The method and results of this experiment are given in this paper