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The computation of the solid angle and the detector efficiency is considering to be one of the most important factors during the measuring process for the radioactivity, especially the cylindrical γ-ray NaI(Tl) detectors nowadays have applications in several fields such as industry, hazardous for health, the gamma-ray radiation detectors grow to be the main essential instruments in radiation protection sector. In the present work, a generic numerical simulation method (NSM) for calculating the efficiency of the γ-ray spectrometry setup is established. The formulas are suitable for any type of source-to-detector shape and can be valuable to determine the full-energy peak and the total efficiencies and P/T ratio of cylindrical γ-ray NaI(Tl) detector setup concerning the truncated conical radioactive source. This methodology is based on estimate the path length of γ-ray radiation inside the detector active medium, inside the source itself, and the self-attenuation correction factors, which typically use to correct the sample attenuation of the original geometry source. The calculations can be completed in general by using extra reasonable and complicate analytical and numerical techniques than the standard models; especially the effective solid angle, and the detector efficiency have to be calculated in case of the truncated conical radioactive source studied condition. Moreover, the (NSM) can be used for the straight calculations of the γ-ray detector efficiency after the computation of improvement that need in the case of γ-γ coincidence summing (CS). The (NSM) confirmation of the development created by the efficiency transfer method has been achieved by comparing the results of the measuring truncated conical radioactive source with certified nuclide activities with the γ-ray NaI(Tl) detector, and a good agreement was obtained after corrections of (CS). The methodology can be unlimited to find the theoretical efficiencies and modifications equivalent to any geometry by essential sufficiently the physical selective considered situation.

Background: This work aims to develop a new imaging system based on a pulse shape discrimination-capable Cs2LiYCl6:Ce (CLYC) scintillation detector combined with the rotational modulation collimator (RMC) technique for dual-particle imaging.Materials and Methods: In this study, a CLYC-based RMC system was designed based on Monte Carlo simulations, and a prototype was fabricated. Therein, a rotation control system was developed to rotate the RMC unit precisely, and a graphical user interface-based software was also developed to operate the data acquisition with RMC rotation. The RMC system was developed to allow combining various types of collimator masks and detectors interchangeably, making the imaging system more versatile for various applications and conditions.Results and Discussion: Operational performance of the fabricated system was studied by checking the accuracy and precision of the collimator rotation and obtaining modulation patterns from a gamma-ray source repeatedly.Conclusion: The prototype RMC system showed reliability in its mechanical properties and reproducibility in the acquisition of modulation patterns, and it will be further investigated for its dual-particle imaging capability with various complex radioactive source conditions.

Objective To provide guidance on basic concepts and elements for radiation safety and security measures for a HDR brachytherapy sealed radioactive source in a medical radiation facility. Methods Brachytherapy sources are Category 2 (High risk-very dangerous) radioactive source and Security Level B applied to cover the range of security measures needed for the associated risk with remote afterloading HDR brachytherapy sources. These security measures were applied based on a risk informed graded approach. A series of in-build and operational safety measures were implemented for equipment and radiation installation. Results The medical radiation facility equipped with adequate radiation protection, detection and monitoring equipment such as survey meter, digital contamination monitor, gamma zone monitor, digital radiation monitor, personnel dosimeter, pocket dosimeter, long handled forceps, shielding material and emergency source storage container etc. to deal with radiological incidences. The contingency plan with security objectives for incidents and procedures for action was prepared in order to implement response function to fulfill the goal of adequate security of radioactive source. The emergency response plan documented against emergency scenarios during transport, loss of radioactive source, theft, sabotage, natural calamities/disasters such as fire, flood and earthquake. Conculsions The paper provides various radiation safety and security aspects for the HDR brachytherapy. The HDR brachytherapy radioactive sources are Type A packages. Transport of radioactive material is the responsibility of consignors, consignee and carriers under the legislation, supervision and control of regulatory authority.

In this study, energy resolution dependent on K-Parameters (Trapezoidal filter system optimizing the count rate) of EXOGAM2 detector with newly developed NUMEXO2 digital electronics using 152Eu radioactive source measured and analysed. This experimental study was carried out at the GANIL (Grand Accelerature National d'Ions Lourd) nuclear research center in France. The measurement and analysis results for different K parameters using a 152Eu radioactive source with low and high gamma energy levels were performed for two EXOGAM2 detectors. Without applying any K parameter, the resolution values expressed by FWHM for the 1.EXOGAM2 detector are measured as 2.360% FWHM for (344.2785 keV), 2.820% FWHM for (1408.006 keV), and 2.451% FWHM for (344.2785 keV), 2.975%FWHM for (1408.006 keV) for the 2.EXOGAM2 detector, respectively. For different K parameters (K=2µs, K=5µs ve K=10µs) detail results are shown below., Bu çalışmada, yeni geliştirilen dijital elektronik NUMEXO2 dijital elektronik ile EXOGAM2(EXOtic GAMma array spectrometer) dedektörünün K-Parametrelerine (sayım oranını optimize eden Trapezoidal filtre sistemi) bağlı enerji çözünürlüğü için 152Eu radyoaktif kaynak kullanılarak ölçüm ve analiz yapılmıştır. Yapılan bu deneysel çalışma Fransa’da bulunan GANIL (Grand Accelerature National d’Ions Lourd) nükleer araştırma merkezinde gerçekleştirilmiştir. Düşük ve yüksek gama enerji seviyesine sahip 152Eu radyoaktif kaynak kullanılarak farklı K-parametreleri için gerçekleştirilen ölçüm ve analiz sonuçları iki EXOGAM2 dedektörü için gerçekleştirilmiştir. Herhangi bir K-parametresi uygulamadan 1.EXOGAM2 dedektörü için FWHM ile ifade edilen çözünürlük değerleri sırası ile (344. 2785 keV) için 2.360% FWHM, (1408.006 keV) için 2.820% FWHM olarak ölçülürken 2.EXOGAM2 dedektörü için ise sırasıyla 2.451% FWHM ve 2.975% FWHM olarak ölçülmüştür. Farklı K-parametreleri (K=2µs, K=5µs ve K=10µs) için ise sonuçlar detayları ile aşağıda gösterilmiştir.

Current methods for the imaging of radioactive sources ignore the surrounding scene information. Reconstruction results do not have real scale meaning, creating difficulties for further disposal and management of nuclear waste. In addition, the traditional reconstruction method requires fixed hardware to directly measure the reconstruction parameters. In recent years, the combination of computer vision and traditional radiation imaging has been greatly performed. The binocular camera is a small, light-insusceptible visual instrument, suitable for integration with other instruments. In this article, we present a method based on binocular vision technology to radioactive source image reconstruction. The binocular camera provides the assisting information about the surrounding scene and replaces the fixed hardware to indirectly achieve the measurement target of reconstruction parameters, which includes an azimuth angle and a distance. In addition, we designed a simple algorithm based on the Hough transform and the regular shape of the waste drum to improve the spatial resolution for good visualization. The experimental rendering results with different transparency degrees provide a good sense of spatial scale.

Accurate localization of radioactive materials is crucial in homeland security and radiological emergencies. Coded-aperture gamma camera is an interesting solution for such applications and can be developed into portable real-time imaging devices. However, traditional reconstruction methods cannot effectively deal with signal-independent noise, thereby hindering low-noise real-time imaging. In this study, a novel reconstruction method with excellent noise-suppression capability based on a multi-layer perceptron (MLP) is proposed. A coded-aperture gamma camera based on pixel detector and coded-aperture mask was constructed, and the process of radioactive source imaging was simulated. Results showed that the MLP method performs better in noise suppression than the traditional correlation analysis method. When the Co-57 source with an activity of 1 MBq was at 289 different positions within the field of view which correspond to 289 different pixels in the reconstructed image, the average contrast-to-noise ratio (CNR) obtained by the MLP method was 21.82, whereas that obtained by the correlation analysis method was 5.85. The variance in CNR of the MLP method is larger than that of correlation analysis, which means the MLP method has some instability in certain conditions.

The simulation codes based on the monte Carlo method are sophisticated averages and have become essential for dosimetry and radiation protection calculations close to the installations that handle radioactive sources. However, before starting to exploit these codes, they must be validated. The aim of this work is to validate two from the Monte Carlo simulation codes most used currently in the world , GEANT4 and MCNP6, for future use in dosimetry and radiation protection requirements in the BOukhalef Ionization Station (SIBO)/ Tangier, Morocco which manipulates a radioactive source of cobalt-60. The validation method is based on a comparison between the simulated results and those obtained by a Fricke system. The codes are well validated, indeed the simulation and experimental results were in good agreement.

Aim of this work is to calibrate the high dose rate (HDR) brachytherapy source 60Co. The radioactive source calibration is a very important part of the quality assurance program for dosimetry of brachytherapy source. The goal of this project is the calibration of HDR Brachytherapy source in radiation therapy is the measurement of the air kerma rate which required actual dose to deliver. The source calibration is an essential part of the quality assurance program for dosimetry of brachytherapy source. This research will help the patient who is involving brachytherapy treatment. HDR brachytherapy source 60Co is inserted directly or in close to the tumor. Most commonly using method for calibration of HDR brachytherapy source 60CO is well type ionization chamber. Calibration of the radioactive source 60Co brachytherapy source is very important for the treatment of cancer patient. We have got the variation between RAKR from TPS and measured Air Kerma Rate of 60Co brachytherapy source are 3.2% and 3.04% and which give very good agreement with the Air Kerma Rate (RAKR) is 5% (from BEBIG protocol, Germany). So, our results were satisfied for brachytherapy treatment. From these results, it must be concluded that, 60Co brachytherapy source is suitable for brachytherapy cancer treatment. It is very difficult to calculate treatment deliver dose without calibrating AKR of HDR brachytherapy source. It is very important to verify the calculated Air Kerma Rate by TPS Air Kerma Rate.

The aim of this work is to develop a Geiger-Muller (GM) detector system for robot to look for a radioactive source in case of a nuclear emergency or in a high radiation environment. In order to find a radiation source easily, a detector system, including 3 detectors, was designed to search γ-ray radiation sources autonomously. First, based on GEANT4 simulation, radiation dose rates in 3 Geiger-Muller (GM) counters were simulated at different source-detector distances, distances between detectors and angles. Various sensitivity analyses were performed experimentally to verify the simulated designed detector system. A mono-energetic C 137 s γ-ray source with energy 662 keV and activity of 1.11 GBq was used for the observation. The simulated results were compared with the experimental dose rate values and good agreements were obtained for various cases. Only based on the dose rates in three detectors, the radiation source with a specific source activity and angle was localized in the different location. A method was adopted with the measured dose rates and differences of distances to find the actual location of the lost γ-ray source. The corresponding angles of deviation and detection limits were calculated to determine the sensitivity and abilities of our designed detector system. The proposed system can be used to locate radiation sources in low and high radiation environments.

In this paper, we present a straightforward analytical method for calculating the efficiencies of an ovoid shape (elliptical cylindrical) detector by using a randomly located point source. To determine the activity of an unknown radioactive source, absolute efficiency is required and we should take into account the attenuation of the gamma-ray photons by the source container and the detector housing materials. The soundness of the resultant straightforward analytical method was successfully confirmed by comparison with some published data.

The present paper is about an experimental evaluation of the terrestrial silicon single-crystalline solar PV module behavior under low gamma radiation. The simultanous proliferation of radioactive sources in Burkina Faso dominated by gamma type and the photovoltaic (PV) systems installations in both urban and rural areas justify this study. There is also high background radiation compared to normal in some region of the country. It has been shown that the photocurrent and the electric power increase while the photovoltage stays constant for an extremely low gamma radiation doses. This work proves that long time exposition to any low radiation can cause the reduction of the performance of the solar PV module. However for greater values of the dose, the photocurrent, the photovoltage and the electric power decrease. Hence, it is so important to protect PV equipments against gamma radiation by adjusting the PV installation height from the ground where high background radiation is notified or by putting reinforced concrete at their bottom faces. The two ways can be combinated adding the respect to radiation protection principle As Low As Reasonably Achievable (ALARA).

Coded-aperture gamma-ray imaging has great application value in the fields of nuclear security, nuclear facility decommissioning, and decontamination verification. However, conventional reconstruction methods cannot handle the signal-independent noise. In this paper, a coded-aperture imaging reconstruction method based on convolutional neural network (CNN) was proposed to improve the performance of image reconstruction and enhance the source position recognition ability of imaging systems. In addition, a compact gamma camera based on cadmium zinc telluride (CZT) pixel detector and uniformly redundant array (MURA) mask was modeled. Monte Carlo simulation data were used to train CNN and test the performance of this method. Furthermore, the reconstruction of the CNN method and the correlation analysis method with different radioactive sources and measurement conditions were compared. Results show that the proposed method can suppress the reconstructed image noise well. The reconstructed images have higher contrast-to-noise ratio (CNR) than the correlation analysis method in radioactive source location.

Locating lost radioactive sources quickly, precisely, and safely is very important in emergency responses of lost radioactive source accidents. This paper describes a source localization approach using an independently developed unmanned aerial vehicle (UAV) radiation monitoring system, which uses a specialized source localization algorithm. Once a radiation anomaly spot is found on the ground, an L × L (m2) square area around the anomaly spot defined as suspicious region is selected to perform an accurate source localization. Then, the UAV radiation monitoring instrument is dispatched to hover at some scheduled detection positions within the suspicious region for radiation measurements. After the last hover finished, the actual source position is calculated by the source localization algorithm program in real time. The source localization algorithm was developed on the basis of the inverse-square law and statistical methods. Five critical factors of the algorithm that may lead to errors in localization such as the meshing number in calculations, the size of the suspicious region, the number of the detection positions, the distribution of the detection positions, and the coverage range of the detection positions were studied by using measurement data from Monte Carlo simulations. Subsequently, the approach was experimentally verified for a 3.7 × 107 Bq 131I source localization. Three experimental scenes were applied such as the source on the grass, next to a tree, and in a puddle. Different distributions of the detection positions and different numbers of the detection positions were studied. The best localization distance error was 30 cm within a 10 × 10 m2 suspicious region, and the calculation time was not more than 0.1 s after a total survey flight of 5 min.

The number (AN), energy (AE) and dose (AD) albedos were measured at the scattering angle of 168° for 59.54 keV gamma-rays emitted from a radioactive source of Am-241. The experiments were carried o...

We developed a novel, accurate and robust energy calibration algorithm for single X-ray photon counting detectors suitable for the use of high-Z sensor materials. The calibratable energy range was demonstrated to extend over a wide interval from 12 keV up to 150 keV and the same method can also be applied to lower or higher X-ray energies. Fluorescence lines of several elemental targets are used as reference up to 75 keV. For higher energies, the reference is given by direct X-ray tube spectra end-points — extracted with a semi-empirical model independently of the broadening by electronic noise. The pixel-wise threshold trimming relies on a target curve fitting iterative procedure which is able to cope with offset, gain and flat-field variations. The algorithm is highly parallelizable and can profit from modern multi-core machines. The proposed method is able to deal with the spectral complexity introduced by atomic fluorescence effects arising in high-Z sensor materials such as CdTe, CdZnTe and GaAs for energies above the corresponding K-edges and enhanced by a decreasing pixel size. We report the qualification results for the case study of a 1 mm-thick CdTe sensor with 150 μ m pixel size, bonded to an IBEX ASIC and calibrated in the range 12–150 keV. The validity of the method was assessed by analyzing calibrated pulse height spectra recorded with Sn and W fluorescence samples and with a 99mTc radioactive source. The global deviation was found to be smaller than 0.5% at 140.5 keV. The residual threshold dispersion was 0.54 keV rms at the Sn K α peak and 1.71 keV rms at the 99mTc γ -decay peak, still with a limited impact on the overall energy resolution of the system.

The advanced image sensors installed on now-ubiquitous smartphones can be used to detect ionising radiation in addition to visible light. Radiation incidents on a smartphone camera’s Complementary Metal Oxide Semiconductor (CMOS) sensor creates a signal which can be isolated from a visible light signal to turn the smartphone into a radiation detector. This work aims to report a detailed investigation of a well-reviewed smartphone application for radiation dosimetry that is available for popular smartphone devices under a calibration protocol that is typically used for the commercial calibration of radiation detectors. The iPhone 6s smartphone, which has a CMOS camera sensor, was used in this study. Black tape was utilized to block visible light. The Radioactivity counter app developed by Rolf-Dieter Klein and available on Apple’s App Store was installed on the device and tested using a calibrated radioactive source, calibration concrete pads with a range of known concentrations of radioactive elements, and in direct sunlight. The smartphone CMOS sensor is sensitive to radiation doses as low as 10 µGy/h, with a linear dose response and an angular dependence. The RadioactivityCounter app is limited in that it requires 4–10 min to offer a stable measurement. The precision of the measurement is also affected by heat and a smartphone’s battery level. Although the smartphone is not as accurate as a conventional detector, it is useful enough to detect radiation before the radiation reaches hazardous levels. It can also be used for personal dose assessments and as an alarm for the presence of high radiation levels.

In the dredging field, the concentration of the solid-liquid two-phase flow in the transmission pipeline is one of the most important parameters. It is measured by a radioactive source densitometer currently. However, the densitometer has limited precision, low intelligence level, and high risk of nuclear pollution. Electrical Resistance Tomography (ERT) is a noninvasive visual detection technology with the advantages of high time resolution, no radiation and low cost. So far, three ERT methods for calculating concentration have been proposed, whereas these methods have individual applicable range and complementary characteristics. Hence, in this paper, a Choquet integral-based method is proposed to fuse the calculation results of these three methods towards higher calculation accuracy. Compared with other fusion methods, the proposed method can overcome these problems of inconsistency, uncertainty, and interaction among various concentration calculation methods. Based on actual data from a working dredger, key parameters in the new method are determined and the concentration calculations of the three existing methods are integrated. Compared with the induvial concentration calculation methods, tested results show that the integrated concentration results are more accurate and consistent with the actual situations under typical dredging conditions.

As public awareness of the threats related to ultrafine aerosols increases, there is a growing need for inexpensive, real-time exposure assessment devices. In this work, the well-established technology used in the smoke detector with a radioactive source was tested in laboratory conditions to check its suitability for determining the number concentration of the ultrafine aerosol. It has been shown that the sensor output changes linearly with the change of diesel soot concentration in the range up to 8.3 × 105 particles cm−3. The sensor has also been shown to be able to detect rapid changes in aerosol concentration. Empirical equations describing the influence of air velocity, temperature, relative humidity, and pressure on the sensor output were determined. The collected results confirm that the ionization sensor can be used to assess ultrafine aerosol exposure, although additional engineering work is required to increase the resolution of the output signal measurement and to compensate for the effects of weather conditions. The presented method can be used for concentration monitoring and risk assessment in environmental engineering, materials engineering, cosmetics industry, textiles, sports, chemical, mining, energy, etc.

Emergency medical responders (EMRs) who treat victims during a radiation emergency are at risk of radiation exposure. In this study, the exposure dose to EMRs treating hypothetically contaminated patients was estimated using a Monte Carlo simulation, and the findings may be useful for educating EMRs and reducing their anxiety. The Monte Carlo simulation estimated radiation doses for adult computational phantoms based on radioactive contamination conditions and radiation dosages from previous studies. At contamination conditions below the typical upper limit of general Geiger–Müller survey meters, the radiation doses to EMRs were estimated to be less than 1 μSv per hour. In cases with greater contamination due to mishandling of an intense radioactive source (hundreds of GBq), the radiation doses to EMRs could reach approximately 100 mSv per hour. These results imply that a radiological accident with a highly radioactive source could expose EMR to significant radiation that exceeds their dose limit. Thus, authorities and other parties should ensure that EMRs receive appropriate education and training regarding measures that can be taken to protect themselves from the possibility of excessive radiation exposure. The results of this study may provide EMRs with information to take appropriate protective measures, although it is also important that they not hesitate to perform lifesaving measures because of concerns regarding radiation.

Scintillators play a key role in the detection chain of several applications which rely on the use of ionizing radiation, and it is often mandatory to extract and detect the generated scintillation light as efficiently as possible. In positron emission tomography (PET), for example, both energy resolution and coincidence resolving time, two of the key detection parameters, depend strongly on the total amount of light which reaches the photodetector surface as well as its spatial and temporal distribution. Typical inorganic scintillators do however feature a high index of refraction, which impacts light extraction efficiency in a negative way. Furthermore, several applications such as preclinical PET rely on pixelated scintillators with small pitch. In this case, applying reflectors on the crystal pixel surface, as done conventionally, can have a dramatic impact of the packing fraction and thus the overall system sensitivity. This paper presents a study on light extraction techniques, as well as combinations thereof, for two of the most used inorganic scintillators (LYSO and BGO). Novel approaches, employing distributed Bragg reflectors (DBRs), metal coatings, and a modified Photonic Crystal (PhC) structure, are described in detail and compared with commonly used techniques. The nanostructure of the PhC is surrounded by a hybrid organic/inorganic silica sol-gel buffer layer which ensures robustness while maintaining its performance unchanged. We observed in particular a maximum light gain of about 41% on light extraction and 21% on energy resolution for BGO, a scintillator which has gained interest in the recent past due to its prompt Cherenkov component and lower cost.

The Timepix3 hybrid-pixel readout chip consists of a matrix made of $256\times256$ square-shaped pixels with a 55- $\mu \text{m}$ pitch, which can be hybridized to several semiconductors, such as silicon (Si) or cadmium telluride (CdTe) with thicknesses up to 5 mm. Working as an event-based readout chip, it simultaneously records the time-over-threshold (ToT) in each pixel, measuring the deposited energy, as well as the time-of-arrival (ToA), with a time resolution of 1.5 ns. In this article, we present the energy calibration of two Timepix3 chips: the first one was bump-bonded with a 300- $\mu \text{m}$ -thick silicon sensor and the second one with a 1-mm-thick CdTe sensor. Both detectors were calibrated with per pixel calibration, using the monochromatic SOurce of Low-Energy X-rays [SOLEX from Henri Becquerel National Laboratory (LNHB) at CEA Saclay] and a set of calibration-grade sealed radioactive sources. Evaluations were carried out over the energy range 6–122 keV for Timepix3 Si and 20 keV–1.332 MeV for Timepix3 CdTe. Based on this experimental procedure, an energy resolution of 2.6 keV (3.4%) at 59.5 keV was observed for Timepix3 Si. For Timepix3 CdTe, this parameter was 5.6 keV (9.4%) at 59.5 keV, 27.24 keV (4.1%) at 661.7 keV, and 47.4 keV (3.5%) at 1.332 MeV. It is the first time that CdTe bump-bonded Timepix3 spectral performances were evaluated for gamma rays above 1 MeV. The reconstruction of the full-energy peak for such high energies is possible due to the ToA information, which allows the identification of all interactions caused by a given gamma ray within the detector.

Leipzig-style skin brachytherapy applicators are an excellent choice for the treatment of small surface lesions, since they can be used with a high dose rate source to produce a tightly constrained treatment field on the desired area of the skin. The dosimetry of these applicators is challenging to independently verify due to their small dimensions, complex energy spectrum and steep dose gradients. In particular the close proximity of the brachytherapy source to the treatment region is cause for concern, since small variations in the position of the radioactive source may significantly affect the resulting dose distribution. The aim of this work was to assess the dosimetry of these applicators using three independently techniques and use these results to examine the effect of variation in source position on the dose distribution. Simulation of different sized applicators in conjunction with a Gammamed + Ir192 source was performed using the EGSnrc Monte Carlo code. Dose distributions at the prescription depth and at the surface generated by Monte Carlo were compared to the outputs of a commercially available treatment planning system and measurements using radiochromic film. Source displacements of up to 0.5 mm in the vertical direction, 0.65 mm in the horizontal direction, and rotations of the source by up to 5° were all simulated. Changes in dose of over 6% at the prescription point and reductions in coverage at the 100% isodose level of several millimetres were observed even for small shifts of the source from its intended position. This work demonstrates that variation in the position of the radiation source is the dominant source of uncertainty in the use of these types of applicators. Centres wishing to perform treatments using these applicators are advised to take steps to control the uncertainty and ensure it remains at an acceptable level.

We proposed a simplified image reconstruction method in 4$\pi$ Compton imaging to determine the intensity and location of point-like gamma-ray sources. The proposed method can be quickly done by fixing an apex of each Compton cone to a center of a Compton imaging detector and using a lookup table of cone projection profiles for all possible combinations. Using a prototype CdTe array detector with the proposed reconstruction method, 4$\pi$ Compton images for a 137Cs gamma-ray point source far from the detector were obtained. Also, the identification of a 137Cs point source in a plastic box was successfully demonstrated.

SRAM-based Field Programmable Gate Arrays (FPGAs) represent an attractive solution for mission-critical computationally intensive applications due to their high integration, flexibility, and computational capabilities. However, the static memory cells of SRAM-based configuration memory present a high sensitivity to radiation effects. Due to the increasing interest in using these devices in radiation environments such as aerospace and high energy physics, the evaluation of their reliability through radiation tests is a key role in their validation. Radiation Testing consists in exposing the physical device to radioactive source or radiation beams and represents an accurate solution for evaluating the device sensitivity. However, this implies high costs both in terms of experimental setup and money due to the low availability of the required facilities. Among the possible solutions, neutron generator testing would represent an efficient solution even if challenging from the instrumentation needed for the experimental setup. In this work, we present a test instrumentation and methodology specific for cost-effective short-time neutron generator testing to efficiently evaluate FPGA radiation-induced soft error sensitivity.

Mossbauer spectroscopy is an important tool in geoscience. Samples are often small or heterogeneous, requiring measurements with small beam size. Such measurements can be carried out in the laboratory using a radioactive source, or at a synchrotron facility in either time or energy domain. This chapter covers practical aspects of carrying out Mossbauer measurements with high spatial resolution in a tutorial style that covers radioactive source properties, how to choose between time and energy domain, practical aspects associated with preparing the sample and setting up a measurement, useful free software for data analysis and analytical data mapping, and concludes with a showcase of research questions in geoscience that have been addressed using Mossbauer spectroscopy with high spatial resolution.

We have characterized a Cerium doped Lanthanum Bromide (LaBr3(Ce) ) crystal coupled with the position-sensitive photo-multiplier system for the gamma-ray imaging application. One can use this detector set-up for the scanning of high purity germanium detectors for pulse shape analysis in gamma-ray spectroscopy experiments and the image formation of an object by Compton back-scattering . The sensor has been tested for energy, timing and position information of the gamma-rays interacting within the detector crystal. The GEANT4 simulation results are consistent with the experimental results. We have reconstructed the image of irradiation spots in different positions throughout the detector crystal. Position resolution is found to be around 3.5 mm with the 2 mm collimated gamma-rays. The 2-d image of hexagonal Bismuth Germanate (BGO) crystal and a cylindrical LaBr3(Ce) crystal have been reconstructed in coincidence technique. The performance of the detector for imaging application has been investigated by coincidence technique in GEANT4 simulation and compared with the experimental data. We have reconstructed the 2-d images of objects with various geometrical shapes by Compton back-scattered events of the gamma-rays. This position-sensitive detector can be used as an absorber of a Compton camera for the image reconstruction of an extended radioactive source. One can also use this kind of set-up as in radiation imaging and many other applications where the energy and source position of the gamma-ray is the main interest.

Most radiation therapy is delivered by linear accelerators capable of photon and electron irradiation. However, alternative modalities may have advantages in some clinical situations. Brachytherapy is radiation delivered by a radioactive source placed within or in close contact to the target, causing a rapid dose falloff with distance. Brachytherapy is classified as low dose rate (LDR) or high dose rate (HDR), and sealed or unsealed sources. Unsealed sources are free-floating radionuclides that can be injected into an anatomical space or administered systemically. Heavy charged particles include protons and heavy ions. These charged particles exhibit a high-dose Bragg peak, with little to no exit dose beyond the intended depth of treatment. Protons have an RBE approximating photons, however heavy ions have a much higher RBE. Neutron beam therapy has a very high RBE, allowing for a greater effect on radioresistant tumors but also greater normal tissue toxicity. Boron-containing drugs may react with neutrons to further increase radiation dose to tumor.

Brachytherapy is a type of radiation therapy that utilizes natural or manufactured radioactive isotopes or radionuclides implanted in the internal organs of the body, to treat cancer lesions, with the aim to deliver high radiation doses to neoplastic cells, without damaging adjacent normal tissues. New instrumentations can allow a safe and effective delivery of radioactive source directly inside the vertebral body, to treat metastatic spine disease. Vertebroplasty (VP) procedure may further stabilizes the radioactive sources and prevents vertebral fractures. Percutaneous thermal ablation techniques (radiofrequency ablation, cryoablation, microwave ablation) are minimally invasive treatment options for bone metastases that are increasingly employed in the interventional oncology practice. Thermal ablation induces low ( 60 °C) temperatures within the targeted tumors, leading to tissue necrosis and cell death. The main indications for thermal ablation procedures (treatment of painful bone metastases, refractory or unsuitable to conventional therapies, local control of limited metastatic disease) and the surgical approach (transpedicular) are similar to those for augmentation techniques, favoring their combined approach.

The Multi-gap Resistive Plate Chambers (MRPCs) provide excellent timing as well as position resolutions at relatively low cost. We have designed and fabricated several six-gap glass MRPCs and extensively studied their performance. In this paper, we describe the detector, the electronics, and the data acquisition system of the setup. We present the data analysis procedure and initial results of our studies to measure the absolute position of a radioactive source (\(^{22}Na\)). We use Time Of Flight (TOF) as well as the hit coordinate information to demonstrate potential applications of MRPCs in medical imaging.

Traditional nuclear imaging methods ignore the surrounding scene information and cannot determine the specific location of the radioactive source. If we can provide the information on scene-data fusion, the problem can be effectively solved. To achieve scene-data fusion, surface reconstruction and texture mapping are indispensable. But the related commonly used algorithms are all based on the point cloud, and the calculation process of the algorithm is very complicated and error-prone. Therefore, in this paper, based on the research background of nuclear imaging, we focus on voxel-based texture mapping and 3-D scene-data fusion. The method we proposed can display the radioactive source and the surrounding scene at the same time and realize the accurate positioning of the radioactive source in nuclear facilities. Experiment results show that the algorithm can accurately observe the intensity ratio and distribution of radioactive sources in nuclear facilities, at the same time can display texture information well, and has a good visualization effect.

An Associated Particle Imaging (API) system consists of a high vacuum chamber where deuterium ions are accelerated on a tritium-loaded target, resulting in alpha particles and neutrons emitted back-to-back, the latter escaping the chamber and used, for example, for tomography of a high-Z sample. An accurate determination of the alpha position is crucial to determine the trajectory of the neutron. Existing API systems have several limitations which a semiconductor-based API detector placed inside the vacuum chamber should not present. The semiconductor material can be either silicon or diamond. In particular, large and fast signals are generated by the alpha interactions in these materials. A pixelated API detector will measure the time and hit position of the alphas produced in the reaction. However, during the lifetime of the generator, the semiconductor detector will be exposed to an intense flux of alpha particles that will degrade its performance over time. To assess the radiation hardness of silicon and diamond against the alpha particles, we exposed single diodes made of either of the two materials to a 5 MeV alpha flux generated by an 241Am radioactive source. During irradiation, the diodes were biased and mounted on current-sensitive preamplifier boards. We have therefore been able to measure insitu the evolution of the waveforms as the damage was accumulating in their substrates.

In several applications which rely on the use of ionizing radiation, scintillators play an important role in the detection chain. An efficient extraction and detection of the generated light is mandatory to provide sufficient information on the high energy particles interacting with the crystal itself. The amount of light extracted, as well as its temporal distribution, have a direct impact on the overall system performance. In positron emission tomography (PET), energy resolution and coincidence resolving time are two of the main parameters, which both depend on the amount of detected light. Furthermore, if pixelated crystals with sub-millimiter pitch are needed, such as in preclinical PET scanners, the use of conventional reflectors on the crystal pixel surface implies a dramatic reduction of the packing fraction, due to their thickness. In this work several light extraction techniques for the most used inorganic scintillators are presented and compared. A novel approach, using a combination of distributed Bragg reflectors, metal coatings, and photonic crystals, is also introduced. A maximum gain of ~40% on light extraction and ~18% on energy resolution was observed.

At present, demands for measurement in industrial process control is advancing to another level, from one-dimension profiling to two- and three-dimension imaging technique. These advancements empowered and assisted in providing more information on the ongoing processes. For industrial process flow study, Single Photon Emission Computed Tomography (SPECT) system, can produce a cross-sectional image of the radioactive source distribution inside a vessel or pipeline. However, an optimum number of measurements is required to reconstruct the cross-section image without compromising or reducing the information on the reconstructed image. In this study, a time average emission computed tomography system was set up and utilised for mapping the intensity of the gamma-ray radiation from a static Barium, Ba-133 isotropic sealed source. The gamma-ray radiation source was placed on the centre and off-centre of the scanning region. Sodium Iodide, NaI scintillation detector then measure the intensity of the gamma-ray (emitted from the radioactive source) at a different angle. The data of gamma-ray intensity distribution were analysed, and the tomographic image of it was reconstructed using the Filtered Back Projection (FBP) algorithm. Although the SPECT system used is a time-average measurement, the tomographic image result is useful for the development of real-time industrial SPECT system that will be used for the imaging system in industrial process control.

The reconstruction of the Cochabamba (Bolivia) radiological incident (IAEA-International Atomic Energy Agency 2004 The Radiological Accident in Cochabamba STI/PUB/1199 (Vienna: IAEA)) was used to assess and evaluate retrospective dosimetry methodologies. For this purpose an unshielded radioactive source was placed inside a transportation vehicle (bus) resembling a radiological exposure device. External doses were assessed using water and anthropomorphic phantoms that were placed at various positions in the vehicle and equipped with both fortuitous dosimeters (chip cards, mobile phones), individual dosimeters (electronic dosimeters, thermoluminescent and optically stimulated luminescence dosimeters) and in three cases also with blood sample tubes in thermos flasks for cytogenetic methods. This paper gives a detailed description of the experimental setup, the results of the reference dosimetry, including organ dose assessment for the phantom closest to the source, and includes a compilation of the main results obtained by the retrospective dosimetry techniques. Comparison is made to the results of dose reconstruction obtained by IAEA during the response to the Cochabamba incident in 2002.

This paper focuses on gamma camera motion parameters estimation applied in accurate radioactive source image reconstruction. Compared with traditional experimental and medical detection scenarios, the practical application scene of a radioactive source detector is more complex, where the detector’s motion is unknown and cannot be directly measured by fixed devices such as trivial encoders. So we used a binocular camera as an auxiliary tool to indirectly estimate motion parameters, whereas this method also brings about the problem of cumulative error. Therefore, we proposed an optimization algorithm to minimize the cumulative error in three steps. The experimental results show that the cumulative error of motion parameters can be greatly reduced. Moreover, It can be confirmed that the binocular camera can be conveniently used as an aid in accurate radioactive source reconstruction, especially if no fixed measurement hardware is provided.

We present a method for localizing an unknown source of radiation in an urban environment using a distributed detector network. This method employs statistical parameter estimation techniques, relying on an approximation for the response of a detector to the source based on a simplified model of the underlying transport phenomena, combined with a Metropolis-type sampler that is modified to propagate the effect of fixed epistemic uncertainties in the material macroscopic cross sections of objects in the scene. We apply this technique to data collected during a measurement campaign conducted in a realistic analog for an urban scene using a network of six mobile detectors. Our initial results are able to localize the source to within approximately 8 m over a scene of size 300 m × 200 m in two independent trials with 30 min count times, including a characterization of the uncertainty associated with the poorly known macroscopic cross sections of objects in the scene. In these measurements, the nearest detectors were between 20 m to 30 m from the source, and recorded count rates between approximately 3 and 13 times background. A few detectors had line-of-sight to the source, while the majority were obscured by objects present in the scene. After extending our model to account for the orientation of the detectors and correcting for anomalies in the measurement data we were able to further improve the localization accuracy to approximately 2 m in both trials.

We have developed a compact gamma-ray beam based on a beam collimator using a lead tube for X-ray fluorescence (XRF) systems. A 59.5-keV gamma-ray from 241Am radioactive source was collimated by a lead tube for excitation of the sample. The spot size of the excited beam was examined experimentally by using a wire scanning method. The elemental compositions of the surface layer of pieces of Sangkhalok and Ban Chiang pottery were investigated using this system. By exciting pieces of the pottery with a gamma-ray beam, the X-ray spectra of the surface layer of the pottery were successfully obtained. The paint and substrate positions of the pottery were separately excited and the X-ray fluorescence spectra of the pottery were collected by a CdTe diode X-ray detector. We were able to develop a compact XRF system and present preliminary results of the elemental compositions of the surface layers of the pottery which clearly showed the differences between paint patterns and substrate positions.

In the first hours or days after an unplanned release of radioactive material to the environment, the radiation detection instruments most widely available to local first responders may be those currently fielded for interdiction missions. This study investigated how such preventative radiological/nuclear detection instruments could perform if repurposed for consequence management missions. A representative sample of three archetypes (body-worn, human-carried, and other/large-detection-volume equipment) encompassed six categories: personal radiation detector, extended-range personal radiation detector, personal emergency radiation detector, radioisotope identification device, human-portable detector/backpack, and vehicle-mounted large-detection-volume detector. Overall 19 models of equipment were included in the study. Laboratory evaluations were designed to assess the capabilities of the instruments in four consequence management missions: exposure rate, integrated exposure, radiation survey, and contamination screening. As applicable, the evaluations included measurement of exposure rate, integrated exposure, overrange response, and angular response. The results were compared to benchmarks from the American National Standards Institute N42.49A. The performance of the instruments for initial screening for contamination was assessed by an automated radioactive source moving past the detectors at various speeds and distances. The results demonstrate that if the equipment is used in accordance with the mission analysis and categories and within the original equipment manufacturer specifications, it is possible to achieve sufficient accuracy to estimate and document doses to responders, plan entries into contaminated areas, detect contamination, and protect the public until such time as outside resources arrive with sufficient numbers of standard health physics instruments and personnel dosimetry to replace the preventative radiological/nuclear detection instruments. This evaluation campaign was conducted to complement the National Council on Radiation Protection and Measurements Report 179, Guidance for Emergency Response Dosimetry.

A method to characterise the quality of a fused silica surface using a β -source is presented. Two fused silica bars ( 5 × 10 × 400 mm 3 ) were fabricated for the Cherenkov detector for proton Flux Measurement installed at vacuum chamber of the Super Proton Synchrotron at CERN. The resolution of such device is defined by the collection efficiency of the Cherenkov light, which is produced by relativistic charged particles in the fused silica. Thus, the surface quality of the radiator should be as good as possible to avoid light losses. The method is based on the scanning of the radiator surface with a 90 S r radioactive source and measurements of the Cherenkov light rate, detected by a PMT attached to the quartz bars. The data have been compared with a Monte-Carlo simulation, providing an estimation of the radiator’s probability of the total internal reflection and inefficient area at the edges of the bars.

The Local manufacturing scanning gamma system designed in Tuwaitha site for nondestructive assay method of radioactive waste drums, where it consist of two main parts with their belongings for controlling the of detector and drum movements up-down and rotation respectively. The volume of the used drum is 220 L with 85 cm height. The drum filled with Portland cement. Six cylindrical holes were made within cement drum and distributed in radial arrangement.The152Eu source inserted in these holes individually, to measure the average angular count rate of gamma radiation. The full energy efficiency value for geometry of drum and detector is computed for thirteen photo peaks. The average efficiency represented by the curve of these peaks indicated the decreasing of efficiency value with increasing the cement thickness and the distance between the detector and the location of radioactive source inside the drum.

The response of a PIN diamond diode with a 4.5 μ m thick i-layer to α -particles from a 210Po radioactive source has been measured and compared to the response from a 300 μ m thick single crystal type IIa diamond. The results show that this PIN diamond diode with thin i-layer can be employed to detect slow neutrons following absorption on a converter boron layer. Such a detector will operate at low voltages and be rather insensitive to gamma background and neutron radiation damage.

Purpose Nasobiliary high-dose-rate (HDR) brachytherapy has emerged as an effective tool to boost the radiation dose for patients with unresectable perihilar cholangiocarcinoma. This work describes a quality assurance (QA) tool for measuring the HDR afterloader's performance, including the transit dose, when the source wire travels through a tortuous nasobiliary catheter path. Methods and Materials The nasobiliary QA device was designed to mimic the anatomical path of a nasobiliary catheter, including the nasal, stomach, duodenum, and bile duct loops. Two of these loops, the duodenum and bile duct loops, have adjustable radii of curvature, resulting in the ability to maximize stress on the source wire in transit. The device was used to measure the performance over time for the HDR afterloader and the differences between intraluminal catheter lots. An upper limit on the transit dose was also measured using radiochromic film and compared with a simple theoretical model. Results The QA device was capable of detecting performance variations among nasobiliary catheter lots and following radioactive source replacement. The transit dose from a nasobiliary treatment increased by up to one order of magnitude when the source wire encountered higher than normal friction. Three distinct travel speeds of the source wire were observed: 5.2, 17.4, and 54.7 cm/s. The maximum transit dose was 0.3 Gy at a radial distance of 5 mm from a 40.3 kU 192Ir source. Conclusions The source wire encounters substantially greater friction when it navigates through the nasobiliary brachytherapy catheter. A QA tool that mimics the nasal, stomach, duodenum, and bile duct loops may be used to evaluate transit dose and the afterloader's performance over time.

The surgical removal of a breast tumour is often followed by postoperative irradiation of the surrounding tissue with a radioactive source (brachytherapy). When performing the MammoSite procedure, a spherical silicone balloon is inserted and filled with a NaCl solution. In a period of about five days in several sessions an iridium-192 source with high activity travels through a catheter into the balloon (afterloading) to irradiate the tumour cells remaining in the cavity. In this study, dose distributions of a MammoSite applicator are investigated based on measurements with a 2D detector array, Monte Carlo simulations and calculations with BrachyVision. The focus is set on the 2D detector array and its possible application in the verification process in 3D brachytherapy treatment planning. The measured dose distributions conform well to the doses of BrachyVision with deviations of less than 5% within the clinically relevant field range. The deviations of the measured and calculated distributions from the simulation results are below 3%. The 2D detector array allows a new verification method for MammoSite treatment plans with sufficient accuracy. Future verifications can be performed without additional Monte Carlo simulations.

Southwest Research Institute investigated the response of a microchannel plate (MCP) detector to isotropic radioactive source emissions at photon energies of 0.662 and approximately 1.25 million electronvolts (MeV) and to a beam of monoenergetic photons (gamma rays) at 2.5, 5, 7, 10, 13, and 20 MeV in the Free Electron Laser Laboratory at Duke University. These measurements were performed to quantify anticipated noise levels of a mass spectrometer instrument for space exploration in a harsh radiation environment and included various incident angles of radiation on the MCP. Measured photon detection efficiencies at 0° incident angle to 0.662 and 1.25 MeV were approximately 0.3%–0.4% and are bracketed by previously published data. In the 2.5- to 20-MeV energy range for which comparable published data are not available, measured detection efficiencies were on the order of 0.02%–0.2%. Radiation transport simulations were compared to the experimental results and showed decent agreement. The measured detection efficiency increased as the incident photon angle was changed from being normal to the MCP surface (0°) to being aligned with the MCP edge (90°). At greater off-axis angles, photons were incident on the side of the detector cartridge and generated secondary radiation from photon interactions in the cartridge materials that subsequently registered MCP counts.

Purpose As an alternative to cylindrical applicators, air‐inflated balloon applicators have been introduced into high‐dose‐rate (HDR) vaginal cuff brachytherapy to achieve sufficient dose to the vagina mucosa as well as to spare organs at risk, mainly the rectum and bladder. Commercial treatment planning systems which employ formulae in the AAPM Task Group No. 43 (TG 43) report do not take into account tissue inhomogeneity. Consequently, the low‐density air in a balloon applicator induces different doses delivered to the mucosa from planned by these planning systems. In this study, we investigated the dosimetric effects of the air in a balloon applicator using the Monte Carlo (MC) method. Methods The thirteen‐catheter Capri™ applicator by Varian™ for vaginal cuff brachytherapy was modeled together with the Ir‐192 radioactive source for the microSelectron™ Digital (HDR‐V3) afterloader by Elekta™ using the MCNP MC code. The validity of charged particle equilibrium (CPE) with an air balloon present was evaluated by comparing the kerma and the absorbed dose at various distances from the applicator surface. By comparing MC results with and without air cavity present, dosimetric effects of the air cavity were studied. Clinical patient cases with optimized multiple Ir‐192 source dwell positions were also explored. Four treatment plans by the Oncentra Brachy™ treatment planning system were re‐calculated with MCNP. Results CPE fails in the vicinity of the air‐water interface. One millimeter beyond the air‐water boundary the kerma and the absorbed dose are equal (0.2% difference), regardless of air cavity dimensions or iridium source locations in the balloon. The air cavity results in dose increase, due to less photon absorption in the air than in water or solid materials. The extent of the increase depends on the diameter of the air balloon. The average increment is 3.8%, 4.5% and 5.3% for 3.0, 3.5, and 4.0 cm applicators, respectively. In patient cases, the dose to the mucosa is also increased with the air cavity present. The point dose difference between Oncentra Brachy and MC at 5 mm prescription depth is 8% at most and 5% on average. Conclusions Except in the vicinity of the air‐mucosa interface, the dosimetric difference is not significant enough to mandate tissue inhomogeneity correction in HDR treatment planning.

Minitype reference radiation (MRR) based on a cesium-137 (Cs-137) isotope radioactive source is a core component for carrying out field calibration on gamma ray dose or dose rate meters. To explore the source of scattering rays in the MRR, and their influence on dose field distribution, we calculated the radiation field of the MRR with different shielding wall materials, different sizes of shielding boxes, and different detectors. The investigation results provide theoretical and technical support for better understanding the MRR, and for developing field calibration technologies.

Background: Regulation requires periodic reconfirmation of the number of radioactive sources in Gamma Knife (GK). To comply with regulations, the total dose output (TDO) method, originally designed to verify amount of radiation received by patients, was adopted as a tool for source security. However, we suspect the TDO method may be unreliable in detecting small numbers of missing sources given that a 2% margin of error is allowed. We propose an alternate method using Gafchromic films to identify number of sources present. Method: To test the efficacy of the TDO method, we simulated real-life source loss by plugging up to 5 sources. TDO after plugging 0, 1, 2, 3, 4, and 5 sources were measured using GK 4C. Percentage change for each additional source plugged was computed. We then proceeded to test the film method. For GK 4C, 2 Gafchromic RTQA2 single sided films measuring 10 × 10 inch were first halved to 5 × 10 inch films. Four 5 × 10 inch films were then adhered to the inner surface of the 18 mm collimator. For GK Perfexion, 2 Gafchromic EBT3 double sided films measuring 10 × 12 inches were combined and rolled into a cone film and adhered to the collimator during installation. In both cases, the films were exposed to 0.5 Gy. Results: TDO was inversely related to the number of source plugged. TDO decreased by more than 2% after 5 plugs. The film method was able to outline all 201 and 192 Co sources for GK4Cand Perfexion respectively. Conclusion: A single lost source is hard to detect using the TDO method given that at least 5 sources had to be lost before the change in TDO will exceed the margin of error (±2%). The film method bypasses this limitation and offers an easy alternative to accurately obtain the number of sources.

The Fukushima nuclear accident caused the release of large amounts of radionuclides into the environment. After the accident, radioactive contamination assessment in environmental samples is essential for radiation dose estimation and radioactive remediation. Mass spectrometry characterized by high sensitivity, low detection limit, short measuring time, high sample throughput, and the capability to obtain atomic ratios is a promising technique for the analysis of the accident released long-lived radionuclides. This review describes the developed analytical methods based on mass spectrometric techniques for the determination of radionuclides (Pu isotopes, U isotopes, radiocesium, radioiodine, radiostrontium, etc.) with regards to Fukushima samples. The real applications of mass spectrometric techniques for radioactive source identification, radiation protection and geochemical tracing are discussed to highlight the importance of mass spectrometric techniques in radioactive contamination assessment after the accident. Future research prospects of mass spectrometric techniques for the analysis of radionuclides with application to Fukushima samples are briefly outlined.

Introduction. The main aim of this study was to fabricate a lead-free tungsten carbide epoxy resin brick that has similar shielding properties to lead brick for low energy gamma shielding in nuclear medicine. The attenuation properties of bricks were characterized by using gamma transmission principle in Single-Photon Emission Computed Tomography (SPECT) scanner. Materials and methods. In this study, various percentage of tungsten carbide epoxy resin were fabricated into brick with thickness of 0.5 cm, 1.0 cm, 1.5 cm and 2.0 cm. Tungsten carbide epoxy resin and lead bricks were irradiated with gamma rays from 99mTc to evaluate the radiation attenuation properties. A detector was used to evaluate the gamma shielding performance at 140 keV. The activity of the radioactive source was measured and recorded. The radiation attenuation of tungsten carbide epoxy resin bricks was compared with lead brick of same size and thickness. The gamma transmission was evaluated by using SPECT. Results. Results showed that tungsten carbide epoxy resin brick attenuates more radiation than a lead brick of the same thickness. This study also found that tungsten carbide epoxy resin brick is an effective radiation shielding material compared to lead. The best tungsten carbide and epoxy resin combination was found with a mixture of 90%:10% by weight, respectively. The study showed that both half-value layer and mean free path are higher at thicker samples for all materials at 140 keV. This study found that tungsten carbide and tungsten carbide epoxy resin bricks have small half-value layer and mean free path compared to lead brick. The values were 0.07 cm and 0.06 cm for lead and tungsten carbide, respectively. Conclusion. This study showed that attenuation coefficient measurement can be performed using gamma transmission principle in SPECT. Tungsten carbide epoxy resin shows high potential to replace lead as radiation shielding material.

Laser-based particle accelerators have been an active field of research for over two decades moving from laser systems capable of one shot every hour to systems able to deliver repetition rates in the Hz regime. Based on the advancements in laser technology, the corresponding detection methods need to develop from single to multiple use with high readout speed. Here, we present an online compact tracker of particles using scintillators with nine resolvable energy levels and a spatial resolution of 3.6 × 3.6 mm2 over the whole active area. This paper describes the design and construction of the detector, which is based on pixellated scintillators embedded inside an absorber matrix. The scintillator pixels are fiberoptically coupled to a camera system for online readout and analysis. Calibration with a radioactive source and first experimental data measuring laser accelerated ions at the PHELIX laser at GSI, Darmstadt, Germany, are presented and discussed.