2,992 research outputs found
Characterisation of silicon strip detectors with a binary readout chip for X-ray imaging
In this paper we describe the development of a multichannel readout system for X-ray measurements using silicon strip detectors. The developed system is based on a binary readout architecture and optimised for detection of X-rays of energies in the range 6}30 keV. The critical component of the system is the 32-channel front-end chip, RX32N, which has been optimised for low noise performance, small channel to channel variation and high counting rate operation. The performance of the chip is demonstrated by measurements of complex X-ray spectra using silicon strip and pad detectors. The obtained results allow to use the system at room temperature with the detection threshold in the range from 500 to 10 000 electrons, which is enough in many crystallographic and medical imaging applications. ( 2000 Elsevier Scienc
Ku & C Band solid state switch matrix for satellite payloads using LTCC multilayer substrate
This paper describes the design and development of Ku and C band solid state switch matrix for multimedia satellite payloads. The design, through the use of advanced packaging techniques, allows significant savings on mass and volume with respect to traditional electromechanical switches while guaranteeing a comparable reliability
Repairing triangle meshes built from scanned point cloud
The Reverse Engineering process consists of a succession of operations that aim at creating a digital representation of a physical model. The reconstructed geometric model is often a triangle mesh built from a point cloud acquired with a scanner. Depending on both the object complexity and the scanning process, some areas of the object outer surface may never be accessible, thus inducing some deficiencies in the point cloud and, as a consequence, some holes in the resulting mesh. This is simply not acceptable in an integrated design process where the geometric models are often shared between the various applications (e.g. design, simulation, manufacturing). In this paper, we propose a complete toolbox to fill in these undesirable holes. The hole contour is first cleaned to remove badly-shaped triangles that are due to the scanner noise. A topological grid is then inserted and deformed to satisfy blending conditions with the surrounding mesh. In our approach, the shape of the inserted mesh results from the minimization of a quadratic function based on a linear mechanical model that is used to approximate the curvature variation between the inner and surrounding meshes. Additional geometric constraints can also be specified to further shape the inserted mesh. The proposed approach is illustrated with some examples coming from our prototype software
A simple micro electret power generator
We developed a novel, yet simple, micro
electret power generator prototype for low-frequency
energy harvesting applications. In this prototype, two
electrodes of the power generator are placed on the
stator. The rotor is only a plate with metal strips of half
of the spatial frequency of the stator plate. The
packaging is to simply fix the stator to a container and
put the rotor directly on top of the stator. CYTOP, a
MEMS-compatible perfluoropolymer, served as the
electret material and charged with corona charging.
The power output was 2.267μW at 60Hz
Parylene-HT-based electret rotor generator
A new micro power generator with parylene HT electret rotor is made. This generator uses parylene HT as a new electret material with a much superior charge density compared to teflon and CYTOP. The highest surface potential observed is 204.58 V/mum, equivalent to a surface charge density of 3.69 mC/m^2. The generator uses an electret rotor. The rotor is a piece of PEEK insulator block coated with a layer of corona-charged parylene HT. Both output electrodes are on the stator. The generator produces 17.98 µW with 80MΩ load at 50Hz and 7.77 µW with an 800MΩ load at 10Hz
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