Detection Efficiency Of Detector Research Articles

Measurement of HFETR reactor power by improved 16N gamma spectrum analysis method

To increase redundancy and diversity of the reactor power measurement, a system for the measurement of reactor power can be established based on neutron activation analysis using 16O(n,p)16N reaction. In this work, gamma spectrums from the coolant of HFETR core are continuously detected by 16N monitor with NaI(Tl) detector and the count rates in the spectrum range of 4.5 MeV-7.5 MeV are obtained. Meanwhile, the overlapping peaks in the given spectrum range are decomposed with Levenberg-Marquardt method during the operation of HFETR. The results confirm that the count rates of full-energy peak, single-escape peak and double-escape peak of 6.13 MeV gamma spectrums is proportionate to the increased reactor power measured by other monitors such as compensated ionization chamber and thermal power. It is possible to achieve the absolute nuclear power measurement by adopting the count rate of 16N 6.13 MeV peak, detection efficiency of detector and 16N source term.

Microchannel plate detector detection efficiency to monoenergetic electrons between 3 and 28 keV.

An unshielded microchannel plate (MCP) detector with an ultrafine pore diameter of 2 μm was irradiated by an electron beam to determine the detection efficiency of electrons for creating detector signals, or counts. Tested electron energies spanned a range of 3 kiloelectron volts (keV) to 28 keV. Higher detection efficiencies were measured at the lower end of this energy range, 0.376 counts per incident electron at 3 keV down to 0.155 at 15 keV with an increase to 0.217 at 18 keV and then another decrease down to 0.15 counts per incident electron at 28 keV. The increase at 18 keV is attributed to primary electron interaction with the L shell electrons of lead (Pb), leading to an increase in secondary electron and X-ray generation within the MCP and thus an increase in detection efficiency. For the electron beam directed normal to the MCP surface, the lowest efficiency of 0.15 counts per incident electron was observed at 28 keV. Detection efficiency was also tested as a function of incident angle with angular steps of 5°. Detection efficiency was more sensitive to the angle of incidence as the incident electron energy decreased. The detection efficiency at 3 keV decreased from 0.376 counts per electron at the zero degree angle (normal incidence to MCP surface) to 0.027 counts per electron at an incident angle of 50° (average in both orientations). At 28 keV, the decrease in detection efficiency as a function of increasing angle was less pronounced, ranging from 0.15 counts per electron at zero degrees to 0.08 counts per electron at 50° (average in both orientations). Experimental data showed lower detection efficiencies compared with previously published data.

Detector Model Parameter Simulation Based on Monte Carlo and Fluka Software

One detector model parameter simulation method based on Monte Carlo and Fluka Software has been proposed in this paper to improve the response of detector for thermal neutron and attain detection sensitivity and detection efficiency of detector. First, α particle attained from neutron reacting with 6LiF at conversion layer and 3H particle angular distribution energy spectrum has been analyzed; second, analogue simulation has been made for 4H-SiC Schottky diode model parameters with adoption of Monte Carlo method and Fluka software; finally, simulation analysis has been made for the influence of 4H-SiC detector on relationship between current pulse characteristics of α particle with different energies and instantaneous current pulse of α particle under fixed voltage.

Scintillating fiber detectors for the HypHI project at GSI

The construction and properties of three sets of two-dimensional scintillating fiber detector arrays for tracking of charged particles used in the HypHI Phase 0 experiment at GSI will be reported in this paper. The position resolutions and the detection efficiency of detectors have been obtained for each layer of detectors by using 6Li primary beams and particles with Z = 1 produced by fragment reactions of 136Xe projectiles on the hydrogen target. Besides, the response of energy deposition of charged particles in the first detector set placed right behind the target has been studied by using light projectile fragments with Z = 1 , 2 and 3 produced by 58Ni and 12C beams. Extracted resolutions for energy deposition and position as well as the detection efficiency fulfill the requirements of the HypHI Phase 0 experiment.

Accurate calibration of a Si(Li) detector for PIXE analysis

Two methods for obtaining thin target PIXE K α calibration factors were compared. The first (relative or experimental) method relied on two different sets of accurate thin film standards, while the second (absolute or theoretical) method involved the use of fundamental physical parameters and an experimental investigation of the Si(Li) detector's detection efficiency. Several critical facets of the calibration procedures are discussed or were carefully investigated. These include the incident beam energy determination, beam current integration, accuracy of thin film standards, solid angle and window thicknesses (Be, Au, Si) of the Si(Li) detector, net K α peak area determination and tail-to-peak ratio as a function of X-ray energy, fluorescence yields and ionization cross sections. The experimental and theoretical calibration factors finally obtained showed excellent agreement, the average difference being only ∼3.5%.

Investigation of multiwire proportional chambers

Investigations on the gas amplification factor in multiwire proportional chambers (MWPC) of various detecting surface areas were carried out utilizing various gas mixtures. Such gas mixtures were also used to evaluate the detection efficiency of the MWPC for 2 mm sense wire spacing and 1 and 2 mm high voltage wire spacing. The effect of the sense wire supports on the detection efficiency of detectors with large surface areas was also studied.