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Straw tubes with resistive cathode and cathode readout were successfully manufactured and tested. The straw tubes were manufactured by ultrasonic welding technique. The resistive cathode electrode was made of diamond like carbon (DLC). The possibility of cathode signal readout from external strip electrodes was successfully demonstrated. The event coordinate along the straw can be accurately determined by applying center of gravity method to the individual strip signals. [ABSTRACT FROM AUTHOR]

Experimental results on pion decays obtained with the PIBETA spectrometer at the Paul Scherrer Institute (PSI) are reviewed. For pion beta decay π+ → π0е+ν (πβ), a precision measurement of relative probability yields Г(πβ) = [1.036 ± 0.004(stat) ± 0.004(syst) ± 0.003(π+→е+ν)] × 10-8, which implies Vud = 0.9728(30) for the corresponding element of the Cabibbo-Kobayashi-Maskawa mixing matrix. Using a sample of 65 × 103 events, relative probability of the π+→е+νγ radiative pion decay (RPD) in the kinematic region of Eγ > 10 MeV and θeγ > 40° is measured as Bexp = 73.86(54) × 10-8. A statistical analysis of measured Ee+ and Eγ distributions for this decay yield the values FV = 0.0258(17) and FA = 0.0117(17) for the pion weak formfactors. Assuming that FV linearly depends on the е+ν invariant mass q2 as FV(q2) = FV(0)(1 + aq2), the slope parameter is extracted as а = 0.10(6). The pion polarizability and neutral-pion lifetime are estimated as αE = 2.78(10) × 10-4 fm3 and τ(π0) = (8.5 ± 1.1) × 10-17 s, respectively. The data for decays π+→ е+ ν and μ+→e+vv¯γ have been collected and are being processed. The follow-up PEN experiment aims at reducing the uncertainty on the π+ → е+ ν relative probability by almost an order of magnitude (to 5 × 10-4). [ABSTRACT FROM AUTHOR]

A prototype of a 2D detector based on specially designed straw tubes with cathode data readout has been developed and tested. This detector exhibits comparable accuracies in measuring radial and longitudinal coordinates. Its rate capability is similar to the capabilities of traditional detectors whose tubes are smaller by half in diameter. [ABSTRACT FROM AUTHOR]

Precise measurement of straw axial coordinate (along the anode wire) with accuracy compatible with straw radial coordinate determination by drift time measurement and increase of straw detector rate capability by using straw cathode readout instead of anode readout are presented. [ABSTRACT FROM AUTHOR]

Detector rate capability is one of the main parameters for designing a new detector for high energy physics due to the permanent rise of the beam luminosity of modern accelerators. One of the widely used detectors for particle track reconstruction is a straw-detector based on drift tubes. The rate capability of such detectors is limited by the parameters of readout electronics. The traditional method of increasing detector rate capability consists in increasing their granularity (the number of 'elementary' detectors = readout channels) by reducing the straw diameter and/or by dividing the straw anode wire into two parts (for decreasing the rate per readout channel). A new method of designing straw detectors with a high rate capability is presented and tested. The method is based on dividing the straw cathode into parts and the independent readout of each part. [ABSTRACT FROM AUTHOR]

The PEN collaboration carries out a precision measurement of the π → eν decay branching ratio at the Paul Scherrer Institute (PSI, Switzerland). A special mini time-projection chamber (mTPC) has been developed for registration of particles in the pion beam. The chamber contains 14 × 10 g/cm of matter on the particle path. The chamber was successfully used during one-year-long run. Design and characteristics of the mTPC are described. [ABSTRACT FROM AUTHOR]

The stands for testing mini drift tubes at the workshop of the Joint Institute for Nuclear Research are described. The test stands are used to perform persistent and effective quality control of detectors under conditions of mass production. Detectors manufactured for the D0 and COMPASS experiments have been tested on these stands. [ABSTRACT FROM AUTHOR]

The procedures and results of mass testing of mini drift tubes in the course of their production for the D0 forward muon system (Tevatron, Fermilab) are described. High-voltage training, checking the stability and uniformity of signals induced by X rays, measuring the wire tension, and leak testing are included in the testing procedure. Owing to the fast and effective testing of detectors under conditions of mass production, the quality of the mini drift tubes is such that virtually no tubes are finally rejected during assembly of the detector system. [ABSTRACT FROM AUTHOR]

The construction and characteristics of the PIBETA spectrometer are described. This spectrometer is designed to implement a program of precise measurement of pion β decay π+ → π0 + e+ + νe at the Paul Scherrer Institute (Switzerland). A spherical calorimeter, consisting of 240 crystals of pure CsI scintillator and embracing a solid angle of ∼3π, 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. [ABSTRACT FROM AUTHOR]

A detector with a profile-based cathode and a two-coordinate cathode readout system has been experimentally investigated. Cathode pads located in each profile along the anode wire are diagonally interconnected, thus forming strips that cross the detector at some angle with respect to the anode wire. Owing to the availability of the two cathode coordinates and the coordinate associated with the anode wire, it is possible to solve the problem of identifying high-multiplicity events in a single detector. [ABSTRACT FROM AUTHOR]

The coordinate detectors based on straw tubes provide a high accuracy of the radial coordinate measurement using the drift time and a small amount of matter in the way of the measured particles. However, the measurement of the coordinate along the wire constitutes a problem. This paper proposes a method for measuring the hit coordinate along the wire with an accuracy better than 1 mm in a straw tube detector using the signals from the cathodes of the detector. [ABSTRACT FROM AUTHOR]