421 research outputs found
Measurements and tests on FBK silicon sensors with an optimized electronic design for a CTA camera
In October 2013, the Italian Ministry approved the funding of a Research &
Development (R&D) study, within the "Progetto Premiale TElescopi CHErenkov made
in Italy (TECHE)", devoted to the development of a demonstrator for a camera
for the Cherenkov Telescope Array (CTA) consortium. The demonstrator consists
of a sensor plane based on the Silicon Photomultiplier (SiPM) technology and on
an electronics designed for signal sampling. Preliminary tests on a matrix of
sensors produced by the Fondazione Bruno Kessler (FBK-Trento, Italy) and on
electronic prototypes produced by SITAEL S.p.A. will be presented. In
particular, we used different designs of the electronics in order to optimize
the output signals in terms of tail cancellation. This is crucial for
applications where a high background is expected, as for the CTA experiment.Comment: 5 pages, 6 figures; Proceedings of the 10th Workshop on Science with
the New Generation of High-Energy Gamma-ray experiments (SciNeGHE) -
PoS(Scineghe2014)00
Millimetric observations with a high-altitude 2.6-m ground based telescope
High atmospheric performances are necessary to ensure efficient sub/millimetre cosmological observations from ground. Low atmospheric components fluctuations along the line of sight are a must for best detector applications.
Such site constraints are attained only at in specific places around the world: highaltitude observatories or, equivalently, polar regions. We are currently involved in
cosmological observations with the MITO project from an Alpine ground station which satisfies such requirements: the Testa Grigia mountain at 3500 m a.s.l., AO—Italy. The Chacaltaya laboratory at 5200 m a.s.l. could also be an appropriate mm-site. One of the goals of MITO is the multifrequency observation of nearby rich clusters of galaxies for measuring the Sunyaev-Zel’dovich effect. Combined S-Z and X-ray measurements yield the Hubble constant and other cosmological information. A dedicated instrument has been designed to minimize spurious contaminations on the signals. The telescope is a 2.6 m Cassegrain with a wobbling subreflector and a 4-band single pixel photometer installed at the focal plane. The bolometric detectors are cooled down to 300 mK by a double stage He3-He4 fridge
Millimetric observations with a high-altitude 2.6-m ground based telescope
High atmospheric performances are necessary to ensure efficient sub/millimetre cosmological observations from ground. Low atmospheric components fluctuations along the line of sight are a must for best detector applications.
Such site constraints are attained only at in specific places around the world: highaltitude observatories or, equivalently, polar regions. We are currently involved in
cosmological observations with the MITO project from an Alpine ground station which satisfies such requirements: the Testa Grigia mountain at 3500 m a.s.l., AO—Italy. The Chacaltaya laboratory at 5200 m a.s.l. could also be an appropriate mm-site. One of the goals of MITO is the multifrequency observation of nearby rich clusters of galaxies for measuring the Sunyaev-Zel’dovich effect. Combined S-Z and X-ray measurements yield the Hubble constant and other cosmological information. A dedicated instrument has been designed to minimize spurious contaminations on the signals. The telescope is a 2.6 m Cassegrain with a wobbling subreflector and a 4-band single pixel photometer installed at the focal plane. The bolometric detectors are cooled down to 300 mK by a double stage He3-He4 fridge
Design of a SiPM-based cluster for the Large Size Telescope camera of CTA
A Silicon Photomultiplier (SiPM)-based photodetector is being built to
demonstrate its feasibility for an alternative silicon-based camera design for
the Large Size Telescope (LST) of the Cherenkov Telescope Array. It has been
designed to match the size of the standard Photomultiplier Tube (PMT) cluster
unit and to be compatible with mechanics, electronics and focal plane optics of
the first LST camera. Here, we describe the overall SiPM cluster design along
with the main differences with respect to the currently used PMT cluster unit.
The fast electronics of the SiPM pixel and its layout are also presented. In
order to derive the best working condition for the final unit, we measured the
SiPM performances in terms of gain, photo-detection efficiency and cross-talk.
One pixel, a unit of 14 SiPMs, has been built. We will discuss also some
preliminary results regarding this device and we will highlight the future
steps of this project.Comment: submitted to NIM
Progress in Monte Carlo design and optimization of the Cherenkov Telescope Array
The Cherenkov Telescope Array (CTA) will be an instrument covering a wide
energy range in very-high-energy (VHE) gamma rays. CTA will include several
types of telescopes, in order to optimize the performance over the whole energy
range. Both large-scale Monte Carlo (MC) simulations of CTA super-sets
(including many different possible CTA layouts as sub-sets) and smaller-scale
simulations dedicated to individual aspects were carried out and are on-going.
We summarize results of the prior round of large-scale simulations, show where
the design has now evolved beyond the conservative assumptions of the prior
round and present first results from the on-going new round of MC simulations.Comment: 4 pages, 5 figures. In Proceedings of the 33rd International Cosmic
Ray Conference (ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at
arXiv:1307.223
Study of single muons with the Large Volume Detector at Gran Sasso Laboratory
The present study is based on the sample of about 3 mln single muons observed
by LVD at underground Gran Sasso Laboratory during 36500 live hours from June
1992 to February 1998. We have measured the muon intensity at slant depths from
3 km w.e. to 20 km w.e. Most events are high energy downward muons produced by
meson decay in the atmosphere. The analysis of these muons has revealed the
power index of pion and kaon spectrum: 2.76 \pm 0.05. The reminders are
horizontal muons produced by the neutrino interactions in the rock surrounding
LVD. The value of this flux is obtained. The results are compared with Monte
Carlo simulations and the world data.Comment: 13 pages, 2 figures, accepted for publication in "Physics of Atomic
Nuclei
Expected performance of the ASTRI-SST-2M telescope prototype
ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is an
Italian flagship project pursued by INAF (Istituto Nazionale di Astrofisica)
strictly linked to the development of the Cherenkov Telescope Array, CTA.
Primary goal of the ASTRI program is the design and production of an end-to-end
prototype of a Small Size Telescope for the CTA sub-array devoted to the
highest gamma-ray energy region. The prototype, named ASTRI SST-2M, will be
tested on field in Italy during 2014. This telescope will be the first
Cherenkov telescope adopting the double reflection layout in a
Schwarzschild-Couder configuration with a tessellated primary mirror and a
monolithic secondary mirror. The collected light will be focused on a compact
and light-weight camera based on silicon photo-multipliers covering a 9.6 deg
full field of view. Detailed Monte Carlo simulations have been performed to
estimate the performance of the planned telescope. The results regarding its
energy threshold, sensitivity and angular resolution are shown and discussed.Comment: In Proceedings of the 33rd International Cosmic Ray Conference
(ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at arXiv:1307.223
INFN Camera demonstrator for the Cherenkov Telescope Array
The Cherenkov Telescope Array is a world-wide project for a new generation of
ground-based Cherenkov telescopes of the Imaging class with the aim of
exploring the highest energy region of the electromagnetic spectrum. With two
planned arrays, one for each hemisphere, it will guarantee a good sky coverage
in the energy range from a few tens of GeV to hundreds of TeV, with improved
angular resolution and a sensitivity in the TeV energy region better by one
order of magnitude than the currently operating arrays. In order to cover this
wide energy range, three different telescope types are envisaged, with
different mirror sizes and focal plane features. In particular, for the highest
energies a possible design is a dual-mirror Schwarzschild-Couder optical
scheme, with a compact focal plane. A silicon photomultiplier (SiPM) based
camera is being proposed as a solution to match the dimensions of the pixel
(angular size of ~ 0.17 degrees). INFN is developing a camera demonstrator made
by 9 Photo Sensor Modules (PSMs, 64 pixels each, with total coverage 1/4 of the
focal plane) equipped with FBK (Fondazione Bruno Kessler, Italy) Near
UltraViolet High Fill factor SiPMs and Front-End Electronics (FEE) based on a
Target 7 ASIC, a 16 channels fast sampler (up to 2GS/s) with deep buffer,
self-trigger and on-demand digitization capabilities specifically developed for
this purpose. The pixel dimensions of mm lead to a very compact
design with challenging problems of thermal dissipation. A modular structure,
made by copper frames hosting one PSM and the corresponding FEE, has been
conceived, with a water cooling system to keep the required working
temperature. The actual design, the adopted technical solutions and the
achieved results for this demonstrator are presented and discussed.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
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