18,380 research outputs found
The STAR MAPS-based PiXeL detector
The PiXeL detector (PXL) for the Heavy Flavor Tracker (HFT) of the STAR
experiment at RHIC is the first application of the state-of-the-art thin
Monolithic Active Pixel Sensors (MAPS) technology in a collider environment.
Custom built pixel sensors, their readout electronics and the detector
mechanical structure are described in detail. Selected detector design aspects
and production steps are presented. The detector operations during the three
years of data taking (2014-2016) and the overall performance exceeding the
design specifications are discussed in the conclusive sections of this paper
The MuPix Telescope: A Thin, high Rate Tracking Telescope
The MuPix Telescope is a particle tracking telescope, optimized for tracking
low momentum particles and high rates. It is based on the novel High-Voltage
Monolithic Active Pixel Sensors (HV-MAPS), designed for the Mu3e tracking
detector. The telescope represents a first application of the HV-MAPS
technology and also serves as test bed of the Mu3e readout chain. The telescope
consists of up to eight layers of the newest prototypes, the MuPix7 sensors,
which send data self-triggered via fast serial links to FPGAs, where the data
is time-ordered and sent to the PC. A particle hit rate of 1 MHz per layer
could be processed. Online tracking is performed with a subset of the incoming
data. The general concept of the telescope, chip architecture, readout concept
and online reconstruction are described. The performance of the sensor and of
the telescope during test beam measurements are presented.Comment: Proceedings TWEPP 2016, 8 pages, 7 figure
Multiwavelength active optics Shack-Hartmann sensor for seeing and turbulence outer scale monitoring
Real-time seeing and outer scale estimation at the location of the focus of a
telescope is fundamental for the adaptive optics systems dimensioning and
performance prediction, as well as for the operational aspects of instruments.
This study attempts to take advantage of multiwavelength long exposure images
to instantaneously and simultaneously derive the turbulence outer scale and
seeing from the full-width at half-maximum (FWHM) of seeing-limited images
taken at the focus of a telescope. These atmospheric parameters are commonly
measured in most observatories by different methods located away from the
telescope platform, and thus differing from the effective estimates at the
focus of a telescope, mainly because of differences in pointing orientation,
height above the ground, or local seeing bias (dome contribution). Long
exposure images can either directly be provided by any multiwavelength
scientific imager or spectrograph, or alternatively from a modified active
optics Shack-Hartmann sensor (AOSH). From measuring simultaneously the AOSH
sensor spot point spread function FWHMs at different wavelengths, one can
estimate the instantaneous outer scale in addition to seeing. Although AOSH
sensors are specified to measure not spot sizes but slopes, real-time r0 and L0
measurements from spot FWHMs can be obtained at the critical location where
they are needed with major advantages over scientific instrument images:
insensitivity to the telescope field stabilization, and being continuously
available. Assuming an alternative optical design allowing simultaneous
multiwavelength images, AOSH sensor gathers all the advantages for real-time
seeing and outer scale monitoring. With the substantial interest in the design
of extremely large telescopes, such a system could have a considerable
importance.Comment: Accepted for publication in A&A. arXiv admin note: text overlap with
arXiv:1201.233
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A flexible organic reflectance oximeter array.
Transmission-mode pulse oximetry, the optical method for determining oxygen saturation in blood, is limited to only tissues that can be transilluminated, such as the earlobes and the fingers. The existing sensor configuration provides only single-point measurements, lacking 2D oxygenation mapping capability. Here, we demonstrate a flexible and printed sensor array composed of organic light-emitting diodes and organic photodiodes, which senses reflected light from tissue to determine the oxygen saturation. We use the reflectance oximeter array beyond the conventional sensing locations. The sensor is implemented to measure oxygen saturation on the forehead with 1.1% mean error and to create 2D oxygenation maps of adult forearms under pressure-cuff-induced ischemia. In addition, we present mathematical models to determine oxygenation in the presence and absence of a pulsatile arterial blood signal. The mechanical flexibility, 2D oxygenation mapping capability, and the ability to place the sensor in various locations make the reflectance oximeter array promising for medical sensing applications such as monitoring of real-time chronic medical conditions as well as postsurgery recovery management of tissues, organs, and wounds
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