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Several nanotechnologies rely on the use of magnetic field for therapeutic purposes, as cancer treatment, inflammation, and diseases of the nervous system. The liposomal drug delivery system is a novel technique that allows a controlled release of drugs encapsulated in a nano-carrier (i.e. liposomes), by the application of an external (electric, magnetic, thermal) stimulus to guarantee a local effect...
Fast scintillation detectors based on Lanthanum Bromide (LaBr3) crystals are nowadays used in nuclear physics experiments, mainly to measure γ-ray energy and time information. The Milano group has developed a 10 large volume (3.5″×8″) LaBr3 detector array (HECTOR+) and collaborates to a a γ-calorimeter based on tens of LaBr3-NaI phoswich detectors (PARIS). A dedicated 16 channels NIM analog module...
To identify the target of Deep Brain Stimulation (DBS) and to choose the optimal parameters for the stimulating signal, intra-operatory microelectrodes are generally used. However, when they are replaced with the chronic macroelectrodes, the effect of the stimulation is often very different. Here, we use numerical simulations to predict the stimulation of neuronal fibers induced by microelectrode...
Several experimental results published in the literature showed that weak pulsed magnetic fields affected the response of the central nervous system. However, the specific biological mechanisms that regulate the observed behaviors are still unclear and further scientific investigation is required. In this work we performed simulations on neuronal models exposed to a specific pulsed magnetic field...
In this work we propose a gamma detector based on Silicon Drift Detectors to readout a 1″×1″ LaBr3:Ce scintillator for gamma-ray spectroscopy and imaging application. Position sensitivity could be useful in nuclear physics research to limit the worsening effect of Doppler broadening in gamma-ray spectroscopy at relativistic velocities. The main difficulty in determining the position of the gamma-ray...
The position sensitivity of a cylindrical continuous 3″ × 3″ (7.62 cm × 7.62 cm) LaBr3:Ce crystal was studied using a collimated beam of 662 keV gamma rays and a spectroscopic shielded PMT (HAMAMATSU R6233-100SEL) with standard passive voltage divider (HAMAMATSU E1198-26). The used crystal is sealed in a capsule and has diffusive/reflective surfaces to optimize the energy resolution. A complete scan...
We investigated the response of a 3″ × 3″ (7.62 cm × 7.62 cm) LaBr3:Ce detector to monochromatic protons within an energy range of 70–230 MeV. The experiment was performed at the new cyclotron at the Cyclotron Centre Bronowice (CCB) of the Henryk Niewodniczański Institute of Nuclear Physics, Krakow, Poland. Protons with energies between 70 and 185 MeV were stopped inside the crystal. Three different...
LaBr3:Ce scintillators have excellent properties, such as energy resolution, time resolution and efficiency. However LaBr3:Ce performances have been investigated only for small or medium volume crystals. We investigated the properties of a large volume 3.5″ × 8″ LaBr3:Ce crystal and we compared them with those measured for smaller detectors. The 3.5″ × 8″ LaBr3:Ce crystal was coupled to a HAMAMATSU...
In nuclear physics basic research and, particularly, in gamma ray spectroscopy, the use of an imaging detector can be extremely useful to reduce the Doppler Broadening effect, in experiments where the gamma-ray source moves at high/relativistic velocity. Thick scintillators (>1 cm) are required to improve the detection efficiency in combination with spatial and energy resolution, hence coating...
The cell membrane poration is one of the main assessed biological effects of nanosecond pulsed electric fields (nsPEF). This structural change of the cell membrane appears soon after the pulse delivery and lasts for a time period long enough to modify the electrical activity of excitable membranes in neurons. Inserting such a phenomenon in a Hodgkin and Huxley neuron model by means of an enhanced...
In nuclear physics basic research and, particularly, in gamma spectroscopy, the use of an imaging detector can be extremely useful to reduce the Doppler Broadening effect in experiments where the gamma-ray source moves with high/relativistic velocity. In this work, we propose to use a recently developed gamma camera, based on CsI:Tl scintillator coupled to an array of Silicon Drift Detectors, for...
In many in-beam gamma spectroscopy experiments the detection of high-energy gamma rays in the range up to 10–20 MeV is of primary importance. New generation high-resolution gamma-ray spectrometers like AGATA and GRETA are composed of position sensitive segmented HPGe detectors and provide a reconstruction of the gamma-ray tracks. The performance of AGATA detectors in this energy range has, however,...
The huge amount of optical photons emitted in burst by Cerium doped Lanthanum bromide scintillators poses a severe constraint on the specifications of photomultipliers, namely they must operate at very large instantaneous current values with minimum saturation of output pulse signals. Acquisition in shape and processing of photomultipliers output pulses by means of high-speed free-running analog to...
In this work we present the first results of a detector characterization technique named Pulse Shape Comparison Scan (PSCS), applied to a large volume segmented HPGe detector of the AGATA array. The experimental data were collected with the Liverpool University scanning system. Processing two sets of singles scan data acquired with a 137Cs (662 keV) gamma collimated source (with the collimation lines...
The position sensitivity in a 3”×3” LaBr3:Ce crystal has been simulated using collimated beams of medium and high energy γ-rays. The simulations have been done using the GEANT4 libraries which allow to follow both the gamma ray interaction in the detector and the scintillation light up to the photocathode. In the simulations the crystal has been coupled to an ideal PSPMT and/or a shielded PMT. The...
Gamma ray tracking arrays like AGATA and GRETA are composed of position sensitive segmented HPGe detectors. In fact the gamma interaction localization with a precision of at least 5 mm is an important step to efficiently perform the tracking. This position information is obtained with the combined use of detector electrode segmentation and Pulse Shape Analysis (PSA). In this work a generalized version...
The 16-channel module (BaFPro) that we have originally developed for processing signals of Barium Fluoride scintillators has been recently adopted to made a pulse shape analysis with signals of Lanthanum Bromide scintillators. Our idea is to use the precision of the fast analog stretcher circuit present in the BaFPro module, to capture in precise way the amplitude peak of the LaBr3 signals. Since...
In this work, a novel technique for the experimental extraction of the position response is presented and applied to an asymmetric 36-fold segmented HPGe detector of the AGATA array. This technique does not require collimators and high intensity sources. The measurement was performed at LNL-INFN placing a 60Co source in different positions close to the detector surface. Specific Geant4 simulations...
A multi-channels data acquisition system for nuclear spectroscopy applications with HPGe detectors has been designed, manufactured and tested. It is based on a front-end electronics for analog signal conditioning, followed by a free running analog to digital converter. The digital output data-stream is collected and transmitted on twisted copper wires by means of programmable logic devices and dedicated...
In the present work, the Neural Networks (NNs) are used to reconstruct the interaction point of an event producing a signal shared among different photodetector in a conventional Anger Camera. The event is caused by the interaction of a medium-high energy gamma ray within a scintillator crystal coupled with Silicon Drift Detectors (SDDs). Two different energy ranges are considered for the incident...
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