Buried plastic scintillator muon telescope (BATATA) Alfaro, R.; De Donato, C.; D’Olivo, J.C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2010, Letnik:
617, Številka:
1
Journal Article
Recenzirano
Muon telescopes have multiple applications in the area of cosmic ray research. We are currently building such a detector with the objective of comparing the ground penetration of muon vs. ...electron-gamma signals originated in cosmic ray showers. The detector is composed by a set of three parallel dual-layer scintillator planes, buried at fixed depths ranging from 120 to
600
g
/
cm
2
. Each layer is
4
m
2
and is composed by 49 rectangular strips of
4
cm
×
2
m
, oriented at a
90
∘
angle with respect to its companion layer, which gives an
xy
-coincidence
pixel of
4
×
4
cm
2
. The scintillators are MINOS extruded polystyrene strips, with an embedded Bicron BC92 wavelength shifting (WLS) fibers, of 1.5
mm in diameter. Light is collected by Hamamatsu H7546B multi-anode PMTs of 64 pixels. The front-end (FE) electronics works in counting mode and signals are transmitted to the surface DAQ stage using low-voltage differential signaling (LVDS). Any strip signal above threshold opens a GPS-tagged
2
μ
s
data collection window. Data, including signal and background, are acquired by a system of FPGA (Spartan 2E) boards and a single-board computer (TS7800).
Stabilization of a platform under wind loads Alexandrov, V. V.; Lokshin, B. Ya; Gomez Esparza, L. ...
Journal of mathematical sciences (New York, N.Y.),
10/2007, Letnik:
146, Številka:
3
Journal Article
The High Altitude Water Cherenkov (HAWC) Observatory is a wide-field-of-view gamma-ray observatory that is optimized to detect gamma rays between 300 GeV and several hundred TeV. The HAWC ...Collaboration recently released their third source catalog (3HWC), which contains 65 sources. One of these sources, the ultra-high-energy gamma-ray source 3HWC J1908+063, may exhibit a hardening of the spectral index at the highest energies (above 56 TeV). At least two populations of particles are needed to satisfactorily explain the highest energy emission. This second component could be leptonic or hadronic in origin. If it is hadronic in origin, it would imply the presence of protons with energies up to ~1 PeV near the source. We have searched other 3HWC sources for the presence of this spectral hardening feature. If observed, this would imply that the sources could make good PeVatron candidates.
The Ultra-High-Energy Source MGRO J1908+06 Malone, Kelly; Abeysekara, Anushka Udara; Albert, Andrea ...
Pos : proceedings of science,
07/2021, Letnik:
395
Journal Article
Recenzirano
Odprti dostop
The TeV gamma-ray source MGRO J1908+06 is one of the highest-energy sources known, with observed emission by the High Altitude Water Cherenkov (HAWC) Observatory extending well past 100 TeV. The ...source exhibits both energy-dependent morphology and a spatially-dependent spectral index. The emission is likely to be dominantly leptonic, and associated with the radio-quiet PSR J1907+0602. However, one-population models do not describe the data well; a second particle population is needed to explain the shape of the spectral energy distribution at the highest energies. This component can be well-described by either leptonic or hadronic hypotheses. We discuss this feature and implications for detection by multi-wavelength and multi-messenger experiments.
A gamma camera is a device used to detect radioactivity in the form of gamma rays emitted by radioactive isotopes that have been introduced into the body as tracers. The position of the source of the ...radioactivity can be plotted and displayed to produce a two dimensional image for medical diagnostic. In this work a hardware architecture for reconstruction of 2D images based in FPGAs (Field Programmable Gate Arrays) in a gamma camera for small animals is presented. The hardware implementation takes the digitized voltage signals produced by the data acquisition electronics of the photomultiplier tubes and process them to allow identifying events and to determine the strength and positions of the interactions based on the logic of Anger to form a planar image. The architecture performs arithmetic operations, formats the data and stores them in memory blocks to be sent to the displaying stage. Through the use of parallelism techniques and an appropriate management of memory, the necessary logic to structure images is implemented inside the FPGA, reducing the time of processing to reach real time performance and to improve flexibility. The system has been implemented using a FPGA Virtex IV of the Xilinx's family obtaining an area occupation of around 22%, achieving an operation frequency of 322 MHz. These results show the potential of the hardware architecture implemented for its application in images reconstruction on line.
Muons decaying in the water volume of a Cherenkov detector of the Pierre
Auger Observatory provide a useful calibration point at low energy. Using the
digitized waveform continuously recorded by the ...electronics of each tank, we
have devised a simple method to extract the charge spectrum of the Michel
electrons, whose typical signal is about 1/8 of a crossing vertical muon. This
procedure, moreover, allows continuous monitoring of the detector operation and
of its water level. We have checked the procedure with high statistics on a
test tank at the Observatory base and applied with success on the whole array.
Muons decaying in the water volume of a Cherenkov detector of the Pierre Auger Observatory provide a useful calibration point at low energy. Using the digitized waveform continuously recorded by the ...electronics of each tank, we have devised a simple method to extract the charge spectrum of the Michel electrons, whose typical signal is about 1/8 of a crossing vertical muon. This procedure, moreover, allows continuous monitoring of the detector operation and of its water level. We have checked the procedure with high statistics on a test tank at the Observatory base and applied with success on the whole array.
