Polystyrene and deuteropolystyrene plastic scintillators for a polarized active target

Results of light output measurements for a polystyrene scintillator deuterated to a degree of 96 at. % are presented. Applications of the deuterated scintillator are considered, in particular, as an active detector. In order to polarize the hydrogen nuclei in the scintillation target, a special additive, 2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPO), was introduced into it. This resulted in a light output of the sample with a thickness of 3.6 mm 50% that of the initial sample.     

Decreasing losses in Y1Ba2Cu3O7−δ rods in the superconducting state

A new method is proposed for growing Y₁Ba₂Cu₃O_7?δ (YBCO) rods and special growth regimes are described which provide decreasing losses in these rods in the superconducting state. It is shown that the thermocapillary mechanism of liquid phase transfer during the melting and crystallization of YBCO is responsible for the formation of a nonsuperconducting phase at the boundaries between crystal blocks. Results of the measurement of current-voltage characteristics of YBCO rods in the superconducting state are presented.     

Calibration of the scintillation trigger detector of the forward muon system for the D0 experiment

A procedure for LED-based calibration of the scintillation trigger detector of the forward muon system for the D0 experiment on the Tevatron collider at the Fermi National Accelerator Laboratory (Batavia, United States) is presented. During its 4-year operation, the deviation in the signal amplitudes averaged over 4214 counters was 4% or less and the variance (σ) of the distribution of these deviations over all counters was 10%. In the same period of time, the signals remained stable in time with an accuracy of 0.23 ns and the variance (σ) of the distribution of these deviations was 0.52 ns. The calibration procedure based on measuring the amplitude response of the detector counters to muons produced by proton-antiproton collisions at the Tevatron collider is also described. The variations in the absolute value of the amplitude responses over a period of 4 years were in the range of +3%...?9%.     

Design of free space WDM router based on holographic concavegrating

A design for a 91×91 router with 0.33 nm channel spacing using a stationary anastigmatic Littrow mount of a holographic concave grating is reported. A simplified method of concave grating analysis is developed for the evaluation of the wavelength router performance. The coupling losses for all routed channels are within -0.9 dB and the power penalty due to coherent crosstalk caused by aberrations and diffraction at the aperture is negligibly small     

A new method for measuring γ-ray energy at the internal calibration of a radioactive source

We developed a new method for measuring γ-ray energies in the internal calibration of a radioactive source under investigation. The measurements were carried out with the spectrometer of delayed coincidences and an optical delay line. This method allows the energies of the reference peak and the γ-ray peak under investigation to be compared, even if they are close or coincide. The possibility of precise γ-ray energy measurements is illustrated with⁶⁰Co and¹⁵⁴Eu isotopes.     

Determining the absolute thermo emfs of conductors using a Y<Subscript>1</Subscript>Ba<Subscript>2</Subscript>Cu<Subscript>3</Subscript>O<Subscript>7 − δ</Subscript> rod

The voltage drop on a 110-mm-long Y₁Ba₂Cu₃O_{7 − δ} (YBCO) rod with a diameter of 7 mm bearing a current of 1 A has been studied as a function of the temperature. It is shown that YBCO rods can be used to measure the absolute thermo emf of conductors in a range of temperatures up to the onset of breakage of the superconducting state. The thermo emf of Ni, Cu, and W conductors was determined.     

Nuclear-energy complexes and the economic and ecological problems of nuclear power development

Conclusions In the long term, serious economic and ecological problems may arise if the required scale and rate of growth of power production is to be ensured while retaining the principle of dispersed location of ever larger power stations in regions with high population density and a developed infrastructure, since the ecological capacity of these regions is limited. This is particularly true of nuclear power, which in the long term will become the main source of electrical energy.Prospects for a solution to the economic and ecological problems of nuclear power and for an increase in its economic efficiency are offered by the construction of nuclear-energy complexes—large industrial units that contain within a single site a group of atomic power stations of total rated power output of the order of 10–50,000 MW and also the facilities of the external fuel cycle, the complexes being remote from densely populated regions but connected to the centers of energy demand by electrical transmission lines.Translated from Atomnaya Énergiya, Vol. 43, No. 5, pp. 369–373, November, 1977.     

Changes in alkaline phosphatase activity and blood phosphorus levels in healthy persons and patients with peptic ulcer

Venous blood total phosphatase activity, its thermostable fraction, and inorganic phosphorus levels were measured thrice within 20-64 min in the course of registration of regular motor activity of the gastrointestinal tract in 38 men aged 18 to 57 (9 healthy and 29 with peptic ulcer). These parameters changed within a wide range over the mentioned period; besides, they depended on the individual features of the organism. Using the chi 2 test at the 5% significance level the authors have demonstrated that total blood alkaline phosphatase activity is increased by the end of a regular cycle in the gastroduodenal system. For more accurate assessment of venous blood total alkaline phosphatase and its thermostable fraction activities and inorganic phosphorus level repeated measurements should be carried out within an hour.