Nuclear Radiation Sensor Research Articles

A novel nuclear radiation cumulant sensor based on spintronic memristor

A designed scheme combining nuclear radiation cumulant sensor with spintronic memristor is proposed. The sensor circuit mainly consists of nuclear radiation converter, spintronic memristor array, current limiting resistor, amplifier. In the presence of nuclear radiation, the nuclear radiation converter will generate photocurrent and cause changes in current and charge in the circuit, which will cause changes in the resistance of the spintronic memristor array in the circuit. Therefore, according to the memory and resistance feature of the spintronic memristor, the nuclear radiation cumulant of the object irradiated for a period of time can be expressed by the spintronic memristor array resistance value. At the same time, we use the threshold of feature to eliminate the influence of dark current in the measurement and achieve the measurement of nuclear radiation cumulant. In order to verify the designed sensor, experiments were carried out under no nuclear radiation, constant and randomly varying radiation intensities, and the effects of memory resistor array intersection and amplifier gain on the sensor were analyzed. The experimental results show that the designed nuclear radiation cumulant sensor based on the spintronic memristor array can complete the measurement of nuclear radiation cumulant. When the nuclear radiation intensity is 1 mGy/h, the nuclear radiation measurement range of the sensor is 0–3.2 mGy, and the sensitivity is 1251.47 Ω/mGy. The change of nuclear radiation intensity will affect the change speed of the resistance value of the spintronic memristor, but it does not affect the measuring range and sensitivity of the sensor. • The nuclear radiation sensor can make continuous multiple measurements of radiation cumulant. • The spintronic memristor eliminates the influence of dark current on the circuit and avoids the measurement errors. • The nuclear radiation sensor has higher flexibility to adjust the sensor measurement range and sensitivity.

Network Detection of Radiation Sources Using Localization-Based Approaches

Radiation source detection is an important problem in homeland security-related applications. Deploying a network of detectors is expected to provide improved detection due to the combined, albeit dispersed, capture area of multiple detectors. Recently, localization-based detection algorithms provided performance gains beyond the simple “aggregated” area as a result of localization being enabled by the networked detectors. We propose the following three localization-based detection approaches: 1) source-attractor radiation detection (SRD); 2) triangulation-based radiation source detection (TriRSD); and 3) the ratio of square distance-based radiation source detection (ROSD-RSD). We use canonical datasets from Domestic Nuclear Detection Office's intelligence radiation sensors systems tests to assess the performance of these methods. Extensive results illustrate that SRD outperforms TriRSD and ROSD-RSD, and other existing detection algorithms based on the sequential probability ratio test and maximum likelihood estimation in terms of both false alarm and detection rates.

Precise, Energy-Efficient Data Acquisition Architecture for Monitoring Radioactivity Using Self-Sustainable Wireless Sensor Nodes

Measuring radiation dosage rates is becoming more and more important in many applications scenarios. Continuously monitoring radiation in contaminated and poorly accessible areas is challenging due to the frequent data collection/transmission combined with long life requirements. We present a self-sustainable wireless sensor node for low power, high precision radiation dosage rate monitoring. We propose an energy-efficient data acquisition algorithm that can reduce the energy per measurement, while guaranteeing minimal loss of precision. The proposed node is designed to work in collaboration with an unmanned aerial vehicle used for two essential mission steps: air-deployment of the wireless sensor nodes at suitable locations, and acquiring data logs via low-power, short-range radio communication in fly-by mode after a wake-up command. The system uses off-the-shelf components for defining the mission, drop-zone, and trajectory, for compressing data and managing communication. The node is equipped with a novel low-power nuclear radiation sensor, and has been designed and implemented with self-sustainability in mind as it will be deployed in hazardous, inaccessible areas. To this end, the proposed node uses a combination of complementary techniques: a low-power microcontroller with non-volatile memory, energy harvesting, adaptive power management, and a nano-watt wake-up radio. Experimental results demonstrate the precision and the low energy consumption of the radiation sensor, the energy efficiency of the whole solution, and the acquisition algorithms. The node consumes only 31 $\mu \text{W}$ in sleep mode and 1.7mW in active mode, and has the capability to achieve perpetual monitoring once deployed.

A Comprehensive Study on Gamma Rays and Fast Neutron Sensing Properties of GAGOC and CMO Scintillators for Shielding Radiation Applications

The WinXCom program has been used to calculate the mass attenuation coefficients (μm), effective atomic numbers (Zeff), effective electron densities (Nel), half-value layer (HVL), and mean free path (MFP) in the energy range 1 keV–100 GeV for Gd3Al2Ga3O12Ce (GAGOC) and CaMoO4 (CMO) scintillator materials. The geometrical progression (G-P) method has been used to compute the exposure buildup factors (EBF) and gamma ray energy absorption (EABF) in the photon energy range 0.015–15 MeV and up to a 40 penetration depth (mfp). In addition, the values of the removal cross section for a fast neutron ∑R have been calculated. The computed data observes that GAGOC showed excellent γ-rays and neutrons sensing a response in the broad energy range. This work could be useful for nuclear radiation sensors, detectors, nuclear medicine applications (medical imaging and mammography), nuclear engineering, and space technology.

Sensitivity of plastic scintillating fiber optic for X and γ radiation, a simulation study

This article introduces and gives the basic performance characteristics of an optical fiber radiation sensing system. Some fundamental characteristics of plastic scintillating fiber (PSF) for electromagnetic radiation (X- and γ-ray) in the energy range of 10–400 keV, are studied by using Geant4 simulation package. The main advantages of PSFs are their fast response, flexibility, and electromagnetic immunity. The PSF could be used as a nuclear radiation sensor or a detector for monitoring and imaging purposes. It is shown that the sensitivity of the PSF in low energy is good enough to use it as a pixel of imaging detector. In order to find quantum efficiency (QE), the energy deposition in fiber, the absorption, conversion, as well as the transfer efficiency is simulated.

Optimization of the energy resolution of the diffusion based nuclear radiation sensors

The diffusion based nuclear radiation sensors have the main advantage of compatibility with the standard IC processing. However, these sensors suffer from a poor energy resolution which is disproportional to its external efficiency. This paper shows that these sensors can be improved by optimizing the detector thickness for a particular application with respect to its energy resolution and external efficiency.

Contactless lifetime measurement in processed and preprocessed high-purity silicon radiation sensors

Abstract A contactless microwave method is presented for the measurement of the recombination lifetime of free carriers in high-ohmic silicon wafers (4 kω cm), which are used for the processing of (nuclear) radiation sensors. It is shown that the bulk lifetime can be measured following processing steps independent of surface parameters, when the intensity of the light source is kept low. The results of the measurements carried out by this method are compared with the results obtained by leakage current measurements. Good agreement is observed between the results.

Monolithic integration of a nuclear radiation sensor and transistors on high-purity silicon

The physical operation of nuclear radiation sensors is briefly reviewed. A description is given of a typical experimental measurement-system setup, which can be divided into two parts: the application-specific part (including the detector and its associated electronics) and the computer-interfaced part (consisting of a multichannel analyzer). A number of recent improvements in the system design are discussed, and an extended description and a physical example are given of one of the most promising new ideas-the monolithic integration of both the radiation sensor and its associated electronics on one high-ohmic silicon substrate. The results proved to be a stimulus for making nuclear radiation sensors smart enough for direct digital input into computer systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Detektoren aus neutronendotiertem Silizium als Kernstrahlungssensoren für Industrieroboter

n-Silicon was produced by neutron transmutation doping from suitable p-Silicon, which was used to manufacture detector structures. It was pointed out, that these detectors are applicable to provide α-, β- and γ-spectrometry and counting at room temperature. For electron counting and spectrometry, the aptitude of the developed detectors as nuclear radiation sensors for industrial robots was analysed and demonstrated.

Semiconductor Particle Detectors: A Reassessment of the Fano Factor Situation

The problems dealt with concern the production of electron-hole pairs in a semiconductor nuclear radiation sensor. The goal is to develop a semiphenomenological model capable of describing the present experimental situation from the standpoint of yield, variance and bandgap dependence. We proceed on the premise that ϵ, the average amount of radiation energy consumed per pair, can be accounted for by a sum of three contributions: the intrinsic bandgap (EG), optical phonon losses r(h ωR), and the residual kinetic energy (9/5)EG. Both the bandgap and the temperature dependence of pair-creation energies conform to this model and suggest that optical phonon losses remain essentially constant [0.5 ≤ r(hωR) ≤ 1.0 eV]. Fano-factor variations are found to reflect the relative weight of phonon losses [ϰ = r(hωR)/EG], but residual energy fluctuations govern the statistical behavior for ϰ2 ≲ 0.3; an application to Ge detectors yields good agreement with the best measurements available (F ≈ 0.13). Finally, it is shown that materials such as Si or CdTe (1.0 ≤ EG ≤ 1.5 eV) provide optimized media in terms of the "ultimate" resolution capability.