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An automated system for acquiring microscopic-resolution radiographic images of biological samples was developed. Mass-produced, low-cost, and easily automated components were used, such as Commercial-Off-The-Self CMOS image sensors (CIS), stepper motors, and control boards based on Arduino and RaspberryPi. System configuration, imaging protocols, and Image processing (filtering and stitching) were defined to obtain high-resolution images and for successful computational image reconstruction. Radiographic images were obtained for animal samples including the widely used animal models zebrafish (Danio rerio) and the fruit-fly (Drosophila melanogaster), as well as other small animal samples. The use of phosphotungstic acid (PTA) as a contrast agent was also studied. Radiographic images with resolutions of up to (7±0.6)μm were obtained, making this system comparable to commercial ones. This work constitutes a starting point for the development of more complex systems such as X-ray attenuation micro-tomography systems based on low-cost off-the-shelf technology. It will also bring the possibility to expand the studies that can be carried out with small animal models at many institutions (mostly those working on tight budgets), particularly those on the effects of ionizing radiation and absorption of heavy metal contaminants in animal tissues. [ABSTRACT FROM AUTHOR]

In this work we show the capabilities of a water Cherenkov detector (WCD) to detect high energy neutrons. We present the simulation of the response of a doped WCD to 500 MeV monochromatic neutrons using Geant4. To do this, a detailed model of the WCD has been implemented. The active volume of the detector is composed of pure water and different concentrations of a 35 Cl based additive. The addition of this dopant shows an enhancement in the detection of high energetic neutrons. The sensitivity of this detector to neutrons achieved in our simulations is a relevant result for cosmic rays and space weather studies. [ABSTRACT FROM AUTHOR]

In this work we will introduce a novel low cost position sensitive thermal neutron detection technique, based on a Commercial Off The Shelf CMOS image sensor covered with a Gadolinium containing conversion layer. The feasibility of the neutron detection technique implemented in this work has been experimentally demonstrated. A thermal neutron detection efficiency of 11.3% has been experimentally obtained with a conversion layer of 11.6 μ m. It was experimentally verified that the thermal neutron detection efficiency of this technique is independent on the intensity of the incident thermal neutron flux, which was confirmed for conversion layers of different thicknesses. Based on the experimental results, a spatial resolution better than 25 μ m is expected. This spatial resolution makes the proposed technique specially useful for neutron beam characterization, neutron beam dosimetry, high resolution neutron imaging, and several neutron scattering techniques. [ABSTRACT FROM AUTHOR]

In this paper we analyse the response of two different Commercial Off The shelf CMOS image sensors as particle detectors. Sensors were irradiated using X-ray photons, gamma photons, beta particles and alpha particles from diverse sources. The amount of charge produced by different particles, and the size of the spot registered on the sensor are compared, and analysed by an algorithm to classify them. For a known incident energy spectrum, the employed sensors provide a dose resolution lower than microGray, showing their potentials in radioprotection, area monitoring, or medical applications. [ABSTRACT FROM AUTHOR]

We present the performance of a novel neutron detector based on a water Cherenkov detector (WCD) employing pure water and a single photomultiplier tube (PMT). The experiments presented in this work were performed using 241 AmBe and 252 Cf neutron sources in different neutron moderator and shielding configurations. We show that fast neutrons from the 241 AmBe and 241 Cf sources, as well as thermal neutrons from a neutron moderator, despite having different spectral characteristics, produce essentially the same pulse histogram shape. This characteristic pulse-height histogram shapes are recorded as a clear signature of neutrons with energies lower than ≃ 11 MeV . This is verified in different experimental conditions. Our estimation of the neutron detection efficiency is at the level of (15±5)%, for fast neutrons. Since water is the material employed as active volume, the results of this study are of interest for the construction of low cost and large active volume neutron detectors for various applications. Of special importance are those related with space weather phenomena monitoring as well as those for the detection of fissile special nuclear material, including uranium or plutonium. [ABSTRACT FROM AUTHOR]

In this work we show the neutron detection capabilities of a water Cherenkov detector (WCD). The experiments presented here were performed using a simple WCD with a single photomultiplier tube (PMT) and a 252Cf neutron source. We compared the use of pure water and water with non contaminant additive as the detection volume. We show that fast neutrons from the 252Cf source can be detected over the flux of atmospheric particles background. Our first estimation for the neutron detection efficiency is at the level of (19)% for pure water and (44)% for the water with the additive. We also present the simulation of the response of the WCD to neutrons using a simulated 252Cf source. We implemented a detailed model of the WCD and of the neutron source spectra using Geant 4. The results of our simulations show the detailed mechanism for the detection of neutrons using WCD and support the experimental evidences presented. Since both active volumes studied, H 2 O pure and with additive, are cheap, non-toxic and easily accessible materials, the results obtained are of interest for the development of large neutron detectors for different applications. Of special importance are those related with space weather phenomena as well as those for the detection of special nuclear materials. We conclude that WCD used as neutron detectors can be a complementary tool for standard neutron monitors based on 3 He. [ABSTRACT FROM AUTHOR]