New instrumental technique for research of the psycho-physiological reactions of the bio-objects under the microwave electromagnetic radiation, modulated by interval patterns of neural activity in the brain registered under different biological motivations, are suggested. The preliminary results of these new tool tests in real psycho physiological experiments on rats are presented.
The effect of the cardiac radio biotelemetry on human heart rate variability has been investigated. The burst transmission mode with a high duty cycle minimizes the influence of microwave artifacts on the reliability of transmitted data.
Negatively charged ions from the alpha particle tracks are detected by the discharge wire counter opened to the air. Ion clusters are transferred from the particle tracks to the detector volume by an air flux. It allows a remote detection of very low concentrations of alpha particles. In contrast to the existing long-range alpha particle detection technique this method employs a detector working in a counting mode using a gas discharge method with an open-air proportional counter that provides sharp selectivity and accuracy of measurements. The device allows to detect alpha contamination over large surface areas, including places hard to reach, using different nozzles such as the tube nozzle or disc nozzle. The basic parameters of the device are: detection distance - 0.5 m; time of detection - 10 s; the sensitivity per unit area - 0.05 Bq/cm(2). Also the auto-calibration technique and results are presented. That allows using the device under different ambient conditions by making an automatic recalibration. (C) 2015 Elsevier Ltd. All rights reserved.
A control circuit for the operation of Hamamatsu R11410-20 photomultiplier tubes (PMTs), which is intended for use in the RED 100 liquid-xenon emission detector, was developed. To prevent the photocathode degradation due to intense flashes that are associated with signals from high-energy cosmic-ray muons, the circuit forms a voltage pulse that is fed to the PMT photocathode and “blocks” the interelectrode gap between the photocathode and the first dynode. Thus, electron current through this gap is stopped for some time, which suffices for the complete collection of ionization electrons in the RED 100 detector after a cosmic muon passes its sensitive volume. The parameters of the circuit are selected such that the PMT relaxation time after the termination of a blocking pulse, which is determined by the transient processes in the divider, is ∼200 μs for a divider with a total resistance of 20 MΩ. This is acceptable for the intended application of the RED 100 detector in an experiment on the search for coherent neutrino scattering off xenon nuclei.
A safety fuse has been designed for the electrical protection of gas-filled detectors in the ATLAS experiment at CERN (Geneva, Switzerland). The fuse is a polished lithium niobate plate with a titanium strip of 91-kΩ resistance deposited by the photolithographic technique. The forced blow-out time of the fuse is 10–50 ms; whereupon the leakage current through it is <1 nA at a 2-kV voltage. The resistance of the fuse case is ≥1012 Ω. Its overall dimensions are 5.8 × 3.8 × 2 mm.