Search results for "Silicon"
showing 10 items of 1391 documents
DEPFET pixel detector in the Belle II experiment
2019
Belle II DEPFET and PXD Collaboration: et al.
First Compton imaging tests with i-TED
2019
The objective of this work is to demonstrate the Compton imaging capabilities of a novel gamma-ray Total-Energy Detector called i-TED. The latter is intended for neutron-capture cross-sections measurements of astrophysical interest, thereby enhancing detection sensitivity by means of the simultaneous combination of Time-of-Flight with Compton-imaging techniques. The developed i-TED demonstrator comprises five position-sensitive radiation detection modules of high energy resolution, which feature an overall position-sensitive field-of-view of 125 cm2, and thus a high efficiency. Each detector module is based on 50x50 mm2 large LaCl 3 (Ce) monolithic crystals optically coupled to 8x8 pixels s…
A Pixelated Silicon Positron Sensitive Imaging Probe
2006
A pixelated silicon positron sensitive imaging probe is under development to precisely localize superficially located tumors accumulating 18F-FDG. 18F-FDG has been a radioisotope of interest mainly because of the high uptake in tumors and the relatively short positron range. Silicon detectors have generally low detection efficiency for high energy photons and can be used for positron detection. We present a pixelated silicon positron sensitive imaging probe that has the 1.4-by-1.4-by-1.0 mm pixel size with equivalent electronic noise of ~1.2 keV FWHM. The small pixel size leads to the high spatial resolution. Probe movement in conjunction with appropriate reconstruction will allow sub-pixel…
Silicon photomultiplier properties at cryogenic temperatures
2015
Abstract The properties of different types of silicon photomultipliers (SiPMs) were studied at cryogenic temperatures. In liquid nitrogen at 77 K, problems with quenching in Hamamatsu SiPMs and with the protective epoxy layer, covering Zecotek SiPMs, were observed. Tests with one Zecotek SiPM were successful after removal of the epoxy layer. In liquid helium at 4 K, fast signals with pulse lengths shorter than 50 ns were observed, the dark count rate was below 10 Hz and no after-pulses were detected. The gain, as a function of over-voltage, was comparable to room temperature. The SiPM׳s response to photons was found to be linear with intensity for low light levels and single-photon detectio…
FARCOS: a versatile and modular Femtoscopy Array for Correlations and Spectroscopy
2012
In the framework of multi-fragmentation experiments the evolution towards two- (or more) particle correlations with stable and radioactive beams calls for the development of a novel detection system featuring high angular and energy resolution and able to reconstruct the particles momentum at high precision. The proposed detection system, named FARCOS (Femtoscopy ARray for COrrelations and Spectroscopy) will be beneficial for different physical cases. To this aim we are building a prototype detection system featuring four telescopes. Each telescope features an active area of 6.4 cm × 6.4 cm and is composed of three detection stages. The first ΔE stage is a Double Sided Silicon Strip Detecto…
High-precision x-ray spectroscopy of highly charged ions with microcalorimeters
2013
The precise determination of the energy of the Lyman α1 and α2 lines in hydrogen-like heavy ions provides a sensitive test of quantum electrodynamics in very strong Coulomb fields. To improve the experimental precision, the new detector concept of microcalorimeters is now exploited for such measurements. Such detectors consist of compensated-doped silicon thermistors and Pb or Sn absorbers to obtain high quantum efficiency in the energy range of 40–70 keV, where the Doppler-shifted Lyman lines are located. For the first time, a microcalorimeter was applied in an experiment to precisely determine the transition energy of the Lyman lines of lead ions at the experimental storage ring at GSI. T…
Next generation of the Albira small animal PET based on high density SiPM arrays
2015
A new design of the small animal PET Albira system which detectors are based on arrays of SiPMs and monolithic LYSO scintillator is presented here. The system is made out of 3 rings of 8 detectors each, resulting on an axial and transaxial FOVs of 148 and 80 mm, respectively. The scanner is thermally stabilized using air-cooling. Working temperatures around 22–25°C are reached with individual detector variations around 0.2°C minimizing dark count rates and gain drifts. One of the most significant improvements of the current system is the accurate photon impact determination within the crystal volume, specially its depth of interaction. This allows the calculation of the true line of respons…
Position sensitive photosensors based on SiPM arrays
2014
Demonstration of a Plasmonic MMI Switch in 10-Gb/s True Data Traffic Conditions
2012
International audience; We report the first experimental performance evaluation of a 75-mu m-long plasmonic multimode interference switch that is hetero-integrated on a silicon-on-insulator platform, operating with 10-Gb/s data signals. The switch exhibits a 2.9-mu s response time and 44.5% modulation depth, while the extinction ratio between the ports alters from 5.4 to -1.5 dB for 35-mW electrical (switching) power. Error-free performance was achieved.
Stationary and Pulsating Dissipative Optical Bullets
2006
We demonstrate the existence of stable optical light bullets in nonlinear dissipative media. Beyond the domain where stable bullets are found, unstable bullets show unusual behaviors, like "optical rockets", pulsating solutions or pattern formation.