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Due to an increase in the use of radiochemistry synthesis systems in Positron Emission Tomography (PET), there is a need for the development of a cost effective radiation detector which can measure localized radiation fields independent of temperature. In this experiment, a 4×4 pixilated Silicon Photomultiplier (SiPM) imaging sensor with optical fiber and scintillator has been designed and constructed...
In a liquid scintillator detector such as EJ-309, neutrons and gamma-rays give rise to different light pulse shapes due to the way they give up their energy but, in addition to this, there are fluctuations in the shape of the light pulse that varies with the point of interaction in the detector volume. The way in which light is dispersed and reflected throughout a detector volume introduces small...
For MeV gamma-ray Astronomy, we have developed an Electron Tracking Compton Camera (ETCC) as a next-generation MeV gamma-ray telescope. An ETCC consists of a three-dimensional electron tracker using a gaseous time projection chamber (TPC) and position-sensitive gamma-ray absorbers using pixel scintillator arrays (PSAs). We carried out the balloon borne experiment in 2006 with a small size ETCC and...
We report on a collaborative test campaign conducted at the Naval Research Laboratory's Mercury pulsed power facility in December of 2012. The experiment sought to use Mercury in the Intense Pulsed Active Detection (IPAD) [1] mode to interrogate a fissionable material target (depleted uranium, DU) and benchmark the effects of shielding the target with either a low-Z (2% borated high-density polyethylene,...
In the present study, a data acquisition system for a GEM one-dimensional array detector is presented. The detector system is to measure the trajectory of photoelectrons produced by cosmic rays. The GEM array detector for the present project has 16 signal channels. The front-end unit provides timing signals from trigger units and energy signals from charge sensitive amplifies and pulse shapers. The...
Many areas of science use x-ray, pump-probe techniques to explore how atomic-scale systems react to an excitation. If a short-duration pump is used to stimulate the sample, the state of the sample can be followed on very fast time scales by varying the delay between the exciting pump and the x-ray probe. Often the difference between excited and static samples is subtle and challenging to determine...
The present work gives an illustration of Monte-Carlo simulations in the domain of imaging in radiotherapy. More precisely a MegaVolt Cone Beam Computed Tomography (MV-CBCT) system is modeled and simulated using the GATE Monte-Carlo platform. For this purpose a flat panel portal imaging from Perkin Elmer was simulated and added to a previously simulated Oncor linear accelerator from SIEMENS. The obtained...
Non-linear morphological edge detectors have been proven to be robust in the presence of noise and able to discriminate between edges and regions corrupted by noise. In this paper a novel non-linear morphological edge detector is presented when implemented as a compact circuit on Quantum Cellular Automata (QCA) in crossbar nanoelectronic architecture. The proposed QCA implementation provides high...
The goal of our work was to study the capability of field effect transistors to measure high power THz radiation at frequencies from 0.1 up to 3 THz and to determine the linear detection limits. We observed different types of the photoresponse dependence on the incident radiation power. We qualitatively explain the unusual sub-linear behavior observed in high intensities.
Antenna-coupled field effect transistors have been developed as plasma-wave THz detectors in both InAs nanowire and graphene channel materials. Room temperature operation has been achieved up to 3 THz, with noise equivalent power levels < 10−10 W/Hz1/2, and high-speed response already suitable for large area THz imaging applications.
This abstract describes a method that is capable of capturing quadrature phase shifted interferograms in the sub-THz and THz spectral range using linear and circularly polarized antenna arrays and FET detectors.
We have fabricated AlGaAs/InGaAs/AlGaAs heterostructure field effect transistors (HFET) with integrated on-chip antennas and we have measured their optical responsivity when mounted in a in-house developed quasi-optical package with a silicon substrate lens
A 10Gbps, 1/5-rate burst mode clock and data recovery (BMCDR) circuit is proposed. The BMCDR is reconfigurable between data gating mode and phase tracking mode to achieve instantaneous phase-locking with jitter suppression for 10 GPON. Incorporating a 1/5-rate CDR with 1:5 demultiplexer, it achieves a high energy efficiency of 1.24pJ/bit. With a 4MHz, 0.22UIpp input data jitter, the recovered clock...
In this paper, we study the noise performance of RTD-gated plasma-wave HEMT THz detectors. It is shown that noise in these devices is dominated by gate tunneling shot noise, and that a smaller effective electron mass promises much improved noise performance by boosting the responsivity while slightly decreasing the noise spectral density (NSD). This implies that it is desirable to realize RTD-gated...
A 2×(4×)128 multiphase time-gated single photon avalanche diode (SPAD) line detector has been designed and fabricated in a high voltage 0.35 µm CMOS technology for Raman spectroscopy. The time positions of the photons can be measured with the resolution of 100 ps using four time gates over the whole line detector simultaneously. This approach enables to reduce the fluorescence background of the Raman...
A gold/silicon Schottky-type plasmonic detector was monolithically integrated with two metal-oxide-semiconductor field-effect transistors (MOSFETs) on a silicon substrate. The output current from the detector was amplified 14000 times by using the MOSFETs.
As the transistor dimension keeps shrinking following trend predicted by Moore's Law, the voltage that transistor can sustain reliably is also reducing. For certain serial interface protocols (like the ubiquitous Universal Serial Bus (USB)) and some legacy input/output interfaces, high voltages like 1.8V, 3.3V and even 5.0V are still being used for protocol compliance. It is costly in silicon fabrication...
Dynamic voltage scaling is a technique for lowering energy consumption in microelectronic systems when the performance required is at times lower than the system's peak capability. This paper proposes a new voltage scaling technique for asynchronous systems which allows fine-grain scaling of supply voltage, i.e. each stage in the pipeline is allowed to scale its voltage independently. Instead of applying...
Operation speed of the single-photon detector based on the silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistor (MOSFET) is affected by the noise and minority carrier lifetime, both of which are found to be dependent on the substrate bias. The noise spectrum are obtained at various substrate voltages in dark condition while keeping the average drain current constant. The noise...
Since terahertz (THz) wave detection mechanism by using oscillations of channel plasma waves based on a field-effect transistor (FET) structure was proposed by Dyakonov and Shur [1], FETs with 2-dimensional electron gas (2DEG) in the channel have been intensively investigated as the promising plasmonic detectors of THz radiations. In this letter, we report the experimental demonstrations of the enhanced...
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