286 research outputs found
A Configurable 64-Channel ASIC for Cherenkov Radiation Detection from Space
This work presents the development of a 64-channel application-specific integrated circuit (ASIC), implemented to detect the optical Cherenkov light from sub-orbital and orbital altitudes. These kinds of signals are generated by ultra-high energy cosmic rays (UHECRs) and cosmic neutrinos (CNs). The purpose of this front-end electronics is to provide a readout unit for a matrix of silicon photo-multipliers (SiPMs) to identify extensive air showers (EASs). Each event can be stored into a configurable array of 256 cells where the on-board digitization can take place with a programmable 12-bits Wilkinson analog-to-digital converter (ADC). The sampling, the conversion process, and the main digital logic of the ASIC run at 200 MHz, while the readout is managed by dedicated serializers operating at 400 MHz in double data rate (DDR). The chip is designed in a commercial 65 nm CMOS technology, ensuring a high configurability by selecting the partition of the channels, the resolution in the interval 8–12 bits, and the source of its trigger. The production and testing of the ASIC is planned for the forthcoming months
Methods to Retrieve the Cloud-Top Height in the Frame of the JEM-EUSO Mission
The Japanese Experiment Module-Extreme Universe
Space Observatory (JEM-EUSO) telescope will measure
ultrahigh-energy cosmic ray properties by detecting the UV
fluorescence light generated in the interaction between cosmic
rays and the atmosphere. Therefore, information on the state of
clouds in the atmosphere is crucial for a proper interpretation of
the data. For a real-time observation of the clouds in the telescope
field of view, the JEM-EUSO will use an atmospheric monitoring
system composed of a light detection and ranging and an infrared
(IR) camera. In this paper, the focus is on the IR camera data.
To retrieve the cloud-top height (CTH) from IR images, three
different methods are considered here. The first one is based
on bispectral stereo vision algorithms and requires two different
views of the same scene in different spectral bands. For the second
one, brightness temperatures provided by the IR camera are converted
to effective cloud-top temperatures, from which the CTH is
estimated using the vertical temperature profiles. A third method
that uses the primary numerical weather prediction model output
parameters, such as the cloud fraction, has also been considered
to retrieve the CTH. This paper presents a first analysis, in which
the heights retrieved by these three methodologies are compared
with the heights given by the Moderate Resolution Imaging
Spectroradiometer sensor installed on the polar satellite Terra.
Since all these methods are suitable for the JEM-EUSO mission,
they could be used in the future in a complementary way to
improve the accuracy of the CTH retrieval
Lateral distributions of EAS muons (Eμ > 800 MeV) measured with the KASCADE-Grande Muon Tracking Detector in the primary energy range 10 16- 10 17 eV
The KASCADE-Grande large area (128 m2) Muon Tracking Detector has been built with the aim to identify muons (Eμthr = 800 MeV) in Extensive Air Showers by track measurements under 18 r.l. shielding. This detector provides high-accuracy angular information (approx. 0.3°) for muons up to 700 m distance from the shower core. In this work we present the lateral density distributions of muons in EAS measured with the Muon Tracking Detector of the KASCADE-Grande experiment. The density is calculated by counting muon tracks in a muon-to-shower-axis distance range from 100 m to 610 m from showers with reconstructed energy of 1016–1017 eV and zenith angle θ<18°. In the distance range covered by the experiment, these distributions are well described by functions phenomenologically determined already in the fifties (of the last century) by Greisen. They are compared also with the distributions obtained with the KASCADE scintillator array (Eμthr = 230 MeV) and with distributions obtained using simulated showers
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