Automated stand check of “B” type TRT ATLAS wheel straw detectors

The automated stand developed and created by the collaboration ATLAS for testing the wheel modules of the TRT ATLAS straw detectors allows a complete check of the module that defines the serviceability of all its channels and measures the gas gain inhomogeneity along its length for each straw. The results of testing the “B” type modules manufactured at the Laboratory of Particle Physics, JINR are presented.     

A physical basis for designing integrated acoustic network systems for underwater observations

A concept for designing network systems for underwater observations based on the joint development of hydroacoustic radiating and receiving elements integrated with different channels of communication is discussed. The main requirements for such systems, principles, and algorithms of their operation under nonstationary conditions of actual marine waters are formulated. The results from several numerical and field experiments demonstrating the performance of certain elements of such systems in typical shallow water basins are presented.     

Full-scale prototype of the circular track detector for the multipurpose detector facility at the NICA acceleration complex

The development of the NICA heavy ion collider, which is now under way, assumes the development of a Multipurpose Detector (MPD), including an end-cap tracker (EC) (which can be a wheel-type tracker based on thin-wall drift tubes (straws) similar to the inner detector of the transition radiation tracker (TRT) in the ATLAS experiment). The identical front and back tracker modules mounted behind the TPC are to ensure the detection of Au-Au ion collision products in the pseudorapidity range from 1.4 to 2.1 with good track parameters of reconstructed events. Each module will contain 60 circular straw planes and maximum straw occupancy will be no higher than 0.2 particle per collision. The NICA EC is substantially different from its analogue and requires a certain amount of R&D. The first results from applying new technology to make a full-scale prototype of the circular EC detector for NICA are presented.     

Transition radiation detectors—“B” trackers manufactured at JINR for ATLAS LHC inner detector

The results of the creation of a transition radiation detector—a “B” tracker on the basis of thin-walled drift tubes (straw tubes) for the inner detector of the ATLAS Large Hadron Collider (LHC)—are presented. The results of preliminary detector testing are described. The basic components and procedures of assembly for 17 eight-layer TRT modules manufactured at JINR are described.     

Q 2 dependence of the measured asymmetry A 1: A test of the Bjorken sum rule

We analyze the proton and deutron data on the spin-dependent asymmetry A ₁(x, Q ²), supposing that the DIS structure functions g ₁(x, Q ²) and F ₃(x, Q ²) have a similar Q ² dependence. As a result, we have found that Λ ₁ ^p −Λ ₁ ⁿ =0.190±0.038 at Q ²=10 GeV² and Λ ₁ ^p −Λ ₁ ⁿ =0.165±0.026 at Q ²=3 GeV²; these values are in the best agreement with the Bjorken sum rule predictions. Pis’ma Zh. éksp. Teor. Fiz. 65, No. 1, 9–14 (10 January 1997) Published in English in the original Russian journal. Edited by Steve Torstveit.     

Multichannel prototype detector based on segmented straws

The design and technology of assembling a prototype detector based on segmented straws with a granularity of 4 cm² are considered. The prototype with a sensitive area of 400 × 200 mm contains two straw planes with a diameter of 4 mm shifted with respect to each other by the straw radius. The total number of registration channels is 360. The results of a test bench study of the prototype are presented.     

Coordinate correction for parallax for gamma-ray beams detected by counters based on thin-film drift tubes

A model was put forward for finding the angle of incidence of a narrow gamma-ray beam and refining its coordinate when the beam is detected by cathode-readout counters based on thin-film drift tubes. The model can be used in solving small-angle scattering problems, which are widely met in X-ray diffraction analysis.     

Time-amplitude characteristics of thin-walled drift tubes (straws) for gas mixtures ArCO2 with CF4 and O2 additives

Results of the investigation of time-amplitude characteristics of thin-walled drift tubes (straws) of different diameters for gas mixtures ArCO₂ with CF₄ and O₂ additives are described. An essential reduction of the sensitivity time of the straw for CF₄ additive is shown, especially with increase the straw diameter. O₂ additive influences the time parameters of the straw insignificantly. CF₄ or O₂ additives with the so-called cleaning properties are of interest for optimization of parameters of detectors with small sensitivity time under the condition of high loadings.     

Straw Chambers for the NA64 Experiment

Physics of Particles and Nuclei Letters - The aim of this work is to describe the characteristics and properties of the particle-tracking detectors created at the Joint Institute for Nuclear...