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We developed a compact detector that was applied to measure Sr/Y-90 radioactivity even in mixture with Cs-134 and Cs-137. A measurement for a sample of which radioactivity was known was conducted.
Although GAPD has been reported to provide good performance as a PET photosensor, it has significant temperature-dependent gain variations causing the drifting of photo-peaks and hence deteriorating the detection sensitivity. Therefore, it is necessary to develop a realtime photo-peak searching method to ensure to apply proper energy window and to sustain uniform sensitivity. This study presented...
An investigation of the luminescence concentration quenching of (Lu1−xPrx)3Al5O12 (LuAG:Pr) ceramics was carried out coupled with microstructural characterization by means of x-ray diffraction (XRD) and attenuated total reflection Fourier transform infrared spectroscopy (ATR FTIR) measurements. It was found that the Pr concentration that maximizes luminescence emission depends on the thermal processing...
Transparent ceramics of Y2O3 doped with 0.5 mol% Tm were fabricated starting from the synthesis of the precursor nanopowder by co-precipitation and calcination followed by its consolidation into fully dense ceramics. Densification and optical transparency of the ceramic were achieved by means of sequential steps of cold isostatic pressing at 206 MPa, vacuum sintering using the two-step method at 1500...
It has been observed that large polyvinyl toluene (PVT)-based gamma ray detectors can suffer internal “fogging” when exposed to outdoor environmental conditions over long periods of time. When observed, this change can result in reduced light collection and performance of the PVT. Investigation of the physical cause of these changes has been explored, and a root cause identified. Mitigation procedures...
The ASTRO-H, which will be launched in 2015, is the sixth in a series of Japanese X-ray satellites. It is an international mission led by JAXA in collaboration with NASA and ESA, aiming to observe astrophysical objects in the X-ray band from 0.5 to 600 keV. One of the important scientific goals is to understand physical processes in the extreme environments of active and variable astrophysical objects,...
A positron emission tomography (PET) detector for neuro-imaging is required to have high signal-to-noise ratio (SNR) as well as high spatial resolution. Time-of-flight (TOF) information can improve SNR of PET by localizing a positron annihilation point. The purpose of this study is to develop a TOF detector for brain PET having spatial resolution ≤ 2 mm and CTR ≤ 330 ps.
In recent years, multi-pixel photon counters (MPPCs) have been actively studied for use in a module for such next-generation PET systems as MRI-PET, DoI-PET, and ToF-PET scanners. In particular, Time of Flight (ToF) measurement is a challenging approach to identify the position of a γ-ray source, according to differences in the arrival times of annihilation γ rays after positron decay. Several simulations...
The Nuclear Metrology Laboratory (LMN), at the IPEN in São Paulo, developed a Digital Coincidence System in order to improve its standardization capabilities. The Software Coincidence System performs data-acquisition, using a digital acquisition card, coupled to a desktop computer, configured and controlled by a proper acquisition-program. Up to four detectors can be connected to available analog...
In an effort to develop new tracking detectors for future experiments at RHIC, we have been developing a short drift GEM tracking detector that has the potential to provide a position resolution ∼ 100 microns even at large angles. We have conducted new high precision studies of our prototype short drift GEM detector at the Fermilab test beam facility in October 2013 and February 2014 which confirm...
Coronary steal (CS) is a physiological process that induces absolute decrease in blood flow in collateralized myocardium compared to resting flow during coronary vasodilation due to redistribution of blood away from collateral-dependent myocardium. Although, CS has been well known for decades, there are very few noninvasive perfusion studies in humans that quantitatively predict the existence of CS...
This study presents the first system characterization results of a novel 1 mm resolution small animal PET system based on cadmium zinc telluride (CZT). The 3-D position-sensitive dual-CZT detector module and readout electronics previously developed in our lab were scaled up to complete significant portions of the final PET system. This sub-system was configured as two opposing detection panels containing...
The proton therapy in oncology requires instantaneous and reliable particle range verification, which can be achieved using prompt gamma emissions. The characteristic requirements of prompt gamma detection include the energy range of up to several MeV, increased background due to secondary emissions and high counting rates. Different concepts make use of the prompt gamma emissions for verification...
Neutron multiplicity counters are used in safeguards to provide rapid assay of samples which contain an unknown amount of plutonium in a potentially unknown configuration. Alternatives to the use of 3He for the detection of thermal neutrons are being investigated. With appropriate detector design, the neutron single, double, and triple coincidence events can be used to extract information of three...
We propose a positron detector with 8 layers of scintillation fibers whose length is 1 m and whose diameter is 0.2 mm. The shape of this detector is like as endoscope but one layer of fibers is spirally rolled clockwise, and another layer is counter-clockwise. The pitch of inner and outer spiral fibers are 85 and 75mm, respectively. This detector can be installed into the intestines from the anus,...
MR based Attenuation Correction (MRAC) is essential for PET quantitation and image quality assurance in PET/MR. Ultra-short TE (UTE) sequence is promising in generating positive contrast for cortical bone but its further adoption is limited by prohibitively long scan time, lack of soft tissue contrast, and potential ambiguity in a tissue classification due to MR imaging artifacts. In this investigation,...
We are developing the OpenPET for in-beam imaging in carbon ion therapy. We have succeeded in showing a proof-of-concept by developing small OpenPET prototypes that we used in the HIMAC. One of the major issues to realize the OpenPET is radiation damage to detectors because a number of fragmented particles are incident on the detectors located downstream from the target. While we are currently using...
Previously we proposed interpolated averaged CT (IACT) as a low dose alternate of cine average CT (CACT) for improved PET/CT attenuation correction (AC) in oncology and cardiology applications. This study aims to evaluate the effectiveness of both average CT protocols in myocardial perfusion SPECT/CT. We simulated a patient injected with Tc-99m-sestamibi using the digital 4D Extended Cardiac Torso...
Free Electron Lasers opened a new window on imaging the motion of atoms and molecules. At SLAC, FEL experiments are performed at LCLS using 120Hz pulses with 1012–1013 photons in 10 femtoseconds (billions of times brighter than the most powerful synchrotrons). This extreme detection environment raises unique challenges, from obvious to surprising.
The compact light weight SATRAM payload is operating in onboard ESA's Proba-V satellite in low Earth orbit since May 2013. Equipped with the Timepix detector the device can determine the composition and spectral characteristics of ionizing radiation (X-ray, light and heavy charged particles) in the satellite environment. Single quantum counting capability and per-pixel energy sensitivity enable quantum-level...
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