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In geology the simulation of the sedimention process deposition is very used on different kind of studies. However a great problem is to get the information without destroy the architecture of the deposited material (since now named testimonial). Usually they do slice the real sample and they take pictures of it. However this technique is too aggressive (invasive) and usually cause damage to the testimonial...
The Micro-Vertex-Detector of the PANDA experiment will be essential for the identification of open charm and instrumental in several central issues of the physics program. Detector R&D for the MVD addresses mechanical optimization of the structure in view of aminimum material budget, electronics design of the components and hardware development. The layout of the detector is accompanied by detailed...
We have developed a Monte-Carlo photon-tracking and readout simulator called SCOUT to study the stochastic behavior of signals output from a simplified rectangular scintillation-camera design. SCOUT models the salient processes affecting signal generation, transport, and readout. Presently, we compare output signal statistics from SCOUT to experimental results for both a discrete and a monolithic...
Iterative methods are currently accepted as the gold standard image reconstruction methods in nuclear medicine. The quality of the final reconstructed image greatly depends on how good the physical processes are modelled in the System-Response-Matrix (SRM). Monte-Carlo based methods are a promising approach to calculate the SRM. However, the increasing granularity used in the detector and image space...
Light sharing PET detector configuration coupled with thick light guide and Geiger-mode avalanche photodiode (GAPD) with large-area microcells was proposed to overcome the energy non-linearity problem and to obtain high light collection efficiency (LCE). Theoretical evaluations were performed for 90 types of PET detector modules. A Monte Carlo simulation was conducted for the three types of LSO block,...
COMPET is an innovative implementation of a small animal PET scanner using a novel block detector geometry, allowing for a high resolution and high sensitivity. One detector block is built up from layers of long LYSO crystals. Perpendicular and interleaved between the crystals, Wave Length Shifting (WLS) fibers are used. The scintillation light created by a gamma ray interacting with a crystal is...
Liquid scintillator detectors are valuable for detection of special nuclear material since they are capable of detecting both neutrons and gamma rays. Furthermore, scintillators can also provide energy information which can help in identification and characterization of the source. In order to deign scintillation based measurement systems appropriate simulation tools are needed. MCNPX-PoliMi is capable...
New scintillator materials have been shown to hold great potential for low-cost, reliable gamma-ray detectors in high-energy astronomy and solar physics. Commercially available silicon photo-multipliers (SiPMs) promise to make scintillator-based instruments even more attractive by reducing mass and power requirements. SiPMs have by now been shown to perform well as readouts for scintillator gamma-ray...
Energy dispersive X-ray diffraction (EDXRD) is a very effective method for explosive and narcotic threat detection in baggage screening. The XRD profiles arise from the molecular interference when X-rays are coherently scattered by a substance. The accurate identification of the target material depends on the ability to detect and resolve the peaks present in the coherent scatter profiles. A high-energy...
Even with the huge advance of computers and computing power, full three dimensional reconstructions of PET and CT scans belong to the future as far as commercially available scanners and software are concerned. Recent investigations have shown that with the aid of Graphical Processing Units (GPUs) extremely high computational speed might be achieved, which lends itself to the implementation of iterative...
We are constructing a 1 mm3 resolution, high sensitivity breast-specific PET camera, consisting out of 2 imaging heads each built out of many layers of 8×8 arrays of 1×1×1 mm3 LYSO crystals coupled to Position Sensitive Avalanche Photo-Diodes (PSAPDs). This paper investigates the effects of shielding on out-of-field background event rate from highly vascular organs like heart, liver, spleen and brain...
Monte Carlo simulations were carried out in order to evaluate the performance of readout solutions for monolithic LYSO blocks, considering several 2D array configurations of discrete SiPMs. Results were compared to conventional multianode PMT readout. Our findings show that a detector module based on an array of 8×8 discrete SiPM may lead to better energy resolution and comparable spatial resolution...
Scatter artifacts impair the CT image quality and the accuracy of CT values. Especially in cases with metal implants and in wide cone-angle flat detector CT scans, scatter artifact removal can be of great value. Typical scatter correction methods try to estimate scattered radiation and subtract the estimated scatter from the uncorrected data. Scatter is found either by time-consuming Monte Carlo-based...
The existing muon detectors for high-energy physics experiments are mainly made of gas chambers such as Resistive Plate Chambers, Limited Streamer Tubes or Multi Wire Proportional Chambers. With the increasing luminosity of the new accelerators and the increment in dimensions of the experiments the development of a new detection technique, which is robust, cheap and capable to sustain high particle...
Calculations are presented to support the claim that fast neutron detection systems can achieve higher performance in detecting weak neutron sources than conventional thermal neutron detection systems involving moderators. Minimum Detectable Limits (MDL) are used as a comparative metric, more representative than the metric of absolute sensitivity, which does not take into account the influence of...
Time-interval (time difference between two consecutive pulses) analysis based on the principles of Bayesian inference was compared with frequentist methods to determine the method with the highest detection probability and the shortest average run length. Using experimental and simulated data, Bayesian analysis of time-intervals (Bayesian (ti)) was compared with Bayesian and frequentist analyses of...
A simulation tool has been developed using the Geant4 toolkit to simulate a phoswich single channel beta gamma coincidence detection system consisting of three layers of different scintillation materials: BC400, CsI and BGO. Monte Carlo simulation techniques are powerful tools for investigating the performance of radiation detectors. Geant4 is a simulation toolkit that can realistically model optical...
The CMS collaboration has developed a fast Monte Carlo simulation of the CMS detector with event production rates ~100 times faster than the GEANT4-based simulation, with comparable accuracy for most of the high level observables to be used in the physics analyses. We discuss basic technical principles of the CMS Fast Simulation and their implementation in the different components of the detector:...
An efficient, two-dimensional, analytic, Spline Reconstruction Technique (SRT) has been presented earlier in the literature. This technique involves the Hilbert transform of the sinogram which is approximated in terms of natural cubic splines. The aim of this study is to evaluate the SRT algorithm using Monte-Carlo simulated sinograms and real PET data, in comparison with three commonly used reconstruction...
Many researchers have been studying on the noise properties and image quality influence on system performance for tomographic imaging in recent years. Most of the works are focused on 2D nuclear medicine imaging. Since X-ray CT dosage has been pushed to a lower level and 3D imaging has been a trend, it is necessary to study the performance of 3D X-ray CT systems. In this work, we presented a new theoretical...
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