Instruments and Experimental Techniques最新文献

A standard diaphragm pump has been upgraded for continuous circulation cleaning of noble gases, the liquid phase of which is used as the working medium of emission detectors, in order to ensure stepless regulation of the flow rate of the purified gas in the range of 8–15 L/min.

The article solves the actual problem of automation of spectroscopic measurements based on the DFS-24 spectrometer. A universal system has been developed, which consists of a control unit, a data-acquisition and recording unit, and a user interface. All tasks and corresponding mechanisms associated with the use of the spectrometer are controlled through an interface developed in the LabVIEW environment. The use of digital processing and control methods allows increasing the resolution of the resolving spectral power of the device and recording weak signals. The results of using the developed control system are presented.

The optical scheme is presented for rotation of laser pulses polarization based only on reflective elements. The losses and the degree of depolarization introduced by this scheme for laser radiation of the visible, near, and midinfrared ranges are determined. The possibility of using the device in the terahertz frequency range is shown. Numerical analysis was performed using experimentally measured complex reflection coefficients for radiation at wavelengths of 532, 808, and 3900 nm for gold mirrors with a protective coating. The possibility of using the rotator for continuous rotation of the polarization of femtosecond laser pulses of the midinfrared range is experimentally shown. It was found that for femtosecond laser pulses at a central wavelength of 3.9 μm (wavelength range of 3600–4200 nm), the losses introduced by the rotator are less than 8% and the degree of polarization in this case varies from 0.95 to 0.985 depending on the rotator position

The design and operating principle of a gas-circulation system used as a target for a gas-jet laser-plasma source are described. The need for such a system is due to the desire to reduce gas consumption while maintaining the performance of the radiation source. The circulation system allows the same volume of gas to be used as a target multiple times. The article presents the design of the system as well as the results of trial operation and assessment of the tightness of the designed system and the operating time on one gas filling.

It is proposed to use the boron lined proportional counter SNM-11 for monitoring the neutron fluence rate of the NG-11I generator. Using the Monte Carlo method, calculation studies of the characteristics of the neutron field in the experimental room were performed, and the optimal location for the proportional counter was selected. The proportionality coefficient between the neutron flunce rate and the count rate of SNM-11 was determined experimentally.

An experimental setup has been developed to optimize gas-cooling processes for thin silicon pixel large-area detectors with high spatial resolution for charged particle track registration. New technical solutions for distributing low-velocity cold gas flows directed between closely spaced cylindrical detector layers have been tested. This cooling scheme provides efficient removal of thermal power, minimizes temperature gradients, and eliminates problems of detector vibrations that may occur at higher gas flow velocities. The identified features of cooling the large-area thin silicon pixel sensors in high-energy physics experiments are discussed.

A description of the methodology for developing analog electronic units using the necessary links and its application to specific tasks is presented. The importance of the proposed methodology for the creation of radio-engineering systems is substantiated. The use of theoretical calculations allows for the synthesis of analog devices and the necessary experimental studies.

An ion injector based on an ECR discharge in a coaxial resonator is described. Its effectiveness is due to the use of several original solutions: a direct connection of the magnetron to an ion source is used, the original magnetic system has a configuration with precise adjustment to the maximum ion current, in addition, it minimizes the combustion zone at the emission hole. The ion current is also significantly increased due to the use of ceramic inserts in the discharge zone. The device does not have a standard microwave path, and the microwave generator (magnetron) is connected directly to the communication loop of the coaxial resonator. The recoverable current of hydrogen ions with a microwave power input of approximately 100 W is 8.5 mA.

An addition to an electron lithograph based on an optical microscope for fast patterning of large-scale elements by the method of contact mask photolithography in ultraviolet radiation on an electronic resistor is presented. The device accelerates the creation of contact pads for solid-state micro- and nanostructures and reduces the risk of sample loss when working with fragile structures.

A method for determining the start pulse for the time-of-flight technique has been developed, significantly improving the accuracy of temporal alignment with the proton beam pulse. The energy spectrum of the pulsed neutron source RADEX has been measured and compared with the results of simulations. The procedure for determining the shape of the neutron pulse over time is described based on the measured shape of the proton beam pulse when neutrons are slowed down in the target. A method for absolute calibration of the spectrometer is outlined, taking into account the effect of neutron energy changes due to multiple elastic scattering of neutrons in the sample. A procedure for recovering neutron capture cross-sections by a nucleus during multiple elastic scattering of neutrons in the sample has been developed. Calibration measurement results for the neutron capture cross-section by Au on the time-of-flight spectrometer at the INES facility are presented. The measured cross-sections are compared with calculated cross-sections based on known resonance parameters and with cross-sections previously obtained in experiments using a thin sample.