Калибровка нейтронных счетчиков токамака Глобус-М2

The paper discusses the results of the calibration of two corona neutron counters used to measure the total neutron yield from the plasma of the Globus-M2 tokamak. The calibration was carried out in the experimental hall of the Globus-M2 facility using an AmBe source. During the calibration, the source moved uniformly around the central solenoid in the equatorial plane of the vacuum chamber, and one of the detectors was gradually moved away from the tokamak along a line with a constant toroidal angle. The values of the calibration coefficient obtained depending on the distance of the detector from the tokamak axis are presented. The calibration technique made it possible to separate in the detector signal the contributions from the direct neutron flux emitted by the plasma and from the flux of neutrons scattered on the elements of the experimental hall.

Measurement System Design of Micro-Dose Experimental Spectrum

Tissue equivalent proportional counter (TEPC) is used to measure the micro-dose spectrum of ionizing radiation. Through changing tissue-equivalent gas pressure, TEPC can simulate the case of radiation energy deposition in different sizes of human cells. Various dosimetric quantities can be obtained such as absorbed dose, radiation quality factor and micro-dose equivalent. Because TEPC simulated cell size is less than the range of ionizing radiation particles, TEPC can be used as linear energy transfer spectroscopy, which can identify different linear energy transfer particles in a mixed radiation field and play an important role in mixed neutron–photon radiation field monitoring and protection. A tissue equivalent proportional counter is designed and manufactured in this paper. Through the built of micro-dose detector signal testing platform, and the realization of measurement of micro-dose detector signal debugging and important parameters (stability, energy resolution, etc.) by [Formula: see text] source method, micro-dose energy spectrum analysis and experimental measurements of Cf-252 source were ultimately achieved. Results show that the detector has good sealing performance and stability, with 12 h stability better than 2.7%. Based on all the above spectra, micro-dosing spectrum of Cf-252 source was experimentally obtained.

The Timing System of the TOTEM Experiment

The new proton timing stations of the Totem experiment are based on UltraFast Silicon Detectors installed in Roman Pots at 220 m from the interaction point 5 at LHC. The sensors have shown in beam test a timing resolution in the range 30–100 ps, depending on the pixel size. The readout is performed through a fast sampler chip: the SAMPIC. The best timing resolution can indeed be obtained only by recording the full waveform of the detector signal. The challenges to integrate the chip and the detector in the Totem-CMS DAQ and control systems will be discussed, together with the solutions adopted. The system has been successfully operated in LHC during some commissioning runs and during the special run in July 2018.