118277826
The Site of the ASTRI SST-2M Telescope Prototype
ASTRI is a Flagship Project financed by the Italian Ministry of Education, University and Research, and led by the Italian National Institute of Astrophysics, INAF. Primary goal of the ASTRI project is the design and production of an end-to-end prototype of Small Size Telescope for the CTA (Cherenkov Telescope Array) in a dual-mirror configuration (SST-2M) equipped with a camera at the focal plane composed by an array of Silicon Photo-Multipliers and devoted to the investigation of the highest gamma-ray energy band. The ASTRI SST-2M prototype will be placed at the INAF M.G. Fracastoro observing station in Serra La Nave on the Etna Mountain near Catania, Italy. After the verification tests, devoted to probe the technological solutions adopted, the ASTRI SST-2M prototype will perform scientific observations on the Crab Nebula and on some of the brightest TeV sources. Here we present the Serra La Nave site, its meteorological and weather conditions, the sky darkness and visibility, and the complex of auxiliary instrumentation that will be used on site to support the calibration and science verification phase as well as the regular data reconstruction and analysis of the ASTRI SST-2M prototype.
21005600
Study of Single Event transients on the VELA ASIC, x-ray detectors FEE for new generation astronomical instruments
It is well known that the use of electronics components in space exposes them to ionizing radiation, which can damage the devices. A careful characterization of the sensitivity to radiation-induced damages is thus of capital importance for the critical devices. VELA (VLSI Electronic for Astronomy) is an ASIC developed at the Politecnico of Milano in collaboration with Max-Planck-Institut Semiconductor Laboratory, in 0.35 µm AMS CMOS technology, which implements the readout front-end electronics for an innovative x-ray detector, the DEPMOS-based APS, Active Pixel Sensor. This sensor is capable of providing an excellent energy resolution even at very high speed readout. The absence of the charge transfer mechanism, makes APS sensors very attractive for harsh radiation space environments. The behavior of the front-end electronics under irradiation is then a critical issue. We present a study of the Single Event Effects induced by heavy ions in VELA, in view of a possible utilization in new generation satellites for X-ray astronomy. The tests have been carried out at the SIRAD facility of the Laboratori Nazionali INFN di Legnaro. In this paper we describe the measurements and the experimental setup, designed and realized ad hoc to monitor Single Event Latch-up (SEL) and Single Event Upset (SEU).
116982610
The ASTRI SST-2M Prototype: Structure and Mirror
The next generation of IACT (Imaging Atmospheric Cherenkov Telescope) will explore the uppermost end of the VHE (Very High Energy) domain up to about few hundreds of TeV with unprecedented sensibility, angular resolution and imaging quality. To this end, INAF (Italian National Institute of Astrophysics) is currently developing a scientific and technological telescope prototype for the implementation of the CTA (Cherenkov Telescope Array) observatory. ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) foresees the full design, development, installation and calibration of a Small Size 4 meter class Telescope. The telescope, named SST-2M, is based on an aplanatic, wide field, double reflection optical layout in a Schwarzschild-Couder configuration. In this paper we report about the technological solutions adopted for the telescope and for the mirrors. In particular the structural and electro-mechanical design of the telescope and the results on the optical performance derived after the development of a prototype of the segments that will be assembled to form the primary mirror.
118604795
The Soft X-ray Imager on board EXIST
The Soft X-ray Imager (SXI) is one of the three instruments on board EXIST, a multi-wavelength observatory in charge of performing a global survey of the sky in hard X-rays searching for Super-massive Black Holes (Grindlay & Natalucci, these Proceedings). One of the primary objectives of EXIST is also to study with unprecedented sensitivity the most unknown high energy sources in the Universe, like high redshift GRBs, which will be pointed promptly by the Spacecraft by autonomous trigger based on hard X-ray localization on board. The presence of a soft X-ray telescope with an effective area of about 950cm2 in the energy band 0.2-3 keV and extended response up to 10 keV will allow to make broadband studies from 0.1 to 600 keV. In particular, investigations of the spectra components and states of AGNs and monitoring of variability of sources, study of the prompt and afterglow emission of GRBs since the early phases, which will help to constrain the emission models and finally, help the identification of sources in the EXIST hard X-ray survey and the characterization of the transient events detected. SXI will also perform surveys: a scanning survey with sky coverage 2pi and a limiting flux of 5x10^(-14) cgs plus other serendipitous.
122001088
The AGILE anticoincidence detector
Abstract AGILE is a γ -ray astrophysics space mission which will operate, starting from 2006, in the 30 MeV–50 GeV energy range with imaging capability also in the 15–45 keV energy band. In order to achieve the required detection sensitivity, all AGILE detectors are surrounded by an anticoincidence detector aimed at charged particle background rejection with an inefficiency as low as 10 −4 . In this work, the design and the structure of this anticoincidence detector are presented, as well as its performances in terms of charged particles detection inefficiency as derived from extensive calibrations performed at CERN PS.
118602523
Field Camera Unit for WSO-UV: Phase A Study Report
World Space Observatory UltraViolet (WSO-UV) is a multipurpose space observatory, made by a 170 cm aperture telescope, capable of UV high-resolution spectroscopy, long slit low-resolution spectroscopy, and deep UV and optical imaging. With a nominal mission life time of 5 years, and a planned extension to 10 years, from a geosynchronous orbit with an inclination of 51.8 degrees, WSO-UV will provide observations of exceptional importance for the study of many unsolved astrophysical problems. WSO-UV is implemented in the framework of a collaboration between Russia (chair), China, Germany, Italy, Spain, and Ukraine. This book illustrates the results of the feasibility study for the Field Camera Unit (FCU), a multi-spectral radial instrument on the focal plane of WSO-UV. The book provides an overview of the key science topics that are drivers to the participation of the Italian astronomical community in the WSO-UV project. The science drivers here illustrated have been used to define the technical requirements for the conceptual and architectural design of the Field Camera Unit (FCU) focal plane instrument. In Chapter I we show that WSO-UV will give a significant contribution to solve the key astronomical problems individuated by the ASTRONET consortium, and which are driving the European Space Agency Cosmic Vision program. Chapter II elucidates the scientific requirements for WSO-UV FCU instrument, discussed in Chapter I, which are translated in a list of verifiable top level requirements usable to make the conceptual design of the FCU instrument. Chapter III is dedicated to the Field Camera Unit opto-mechanical design, its detectors and electronics subsystems. Finally, Chapter IV outlines the AIV and GSE plans and activities for the FCU instrument.
19998877
The GAP project - GPU for realtime applications in high energy physics and medical imaging
We describe a pilot project for the use of GPUs (Graphics Processing Units) in online triggering applications for high energy physics experiments. Two major trends can be identified in the development of trigger and DAQ systems for particle physics experiments: the massive use of general-purpose commodity systems for data acquisition, such as commercial multicore PC farms, and the reduction of trigger levels implemented in hardware, aimed at a pure software selection system (trigger-less). The very innovative approach presented here aims at exploiting the parallel computing power of commercial GPUs to perform fast software-based computations both in early trigger stages and in high level triggers. General-purpose computing on GPUs is emerging as a new paradigm in several scientific fields. So far, however, GPU applications have only been tailored in order to accelerate offline computation. With the steady reduction of GPU latencies, and the increase in link and memory throughput, such devices have become mature for use in real-time applications in high energy physics data acquisition and trigger systems. We will discuss in detail the use of online parallel computing on GPUs for synchronous low level fixed-latency triggers. We will discuss the preliminary results of a first field test within the NA62 experiment at CERN. The use of GPUs in high level triggers will be also discussed. The ATLAS experiment at CERN, and in particular its muon trigger, will be taken as a case study for possible applications.
16875653
An ultra fast silicon pixel detector for the NA62 experiment : The Gigatracker
The beam spectrometer of the NA62 experiment has to sustain high and non-uniform beam rate (∼1.5 MHz/mm 2 in the hot center and 0.8-1.0 GHz in total, hence the name Gigatracker) and should preserve beam divergence and limit beam hadronic interactions. The Gigatracker has to provide precise momentum, time and angular measurements on every single track of the secondary 75 GeV/c hadron beam with a timing precision of 150 ps (rms). To meet these requirements , three hybrid silicon pixel detector stations will be installed in vacuum. An adequate strategy to compensate the discriminator time-walk must be implemented and R&D investigating two different options is ongoing. Two prototypes have been designed in order to have an experimental comparison of the performances: one approach is based on the use of a constant-fraction discriminator followed by an on-pixel TDC, while the other one is based on the use of a Time-over-Threshold circuit followed by a TDC shared by a group of pixels. c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.
110409140
A 9-Channel, 100 ps LSB Time-to-Digital Converter for the NA62 Gigatracker Readout ASIC (TDCpix)
The TDCpix ASIC is the readout chip for the Gigatracker station of the NA62 experiment. Each station of the Gigatracker needs to provide time stamping of individual particles to 200 ps-rms or better. Bump-bonded to the pixel sensor the ASIC serves an array of 40 columns x 40 pixels. The high precision time measurement of the discriminated hit signals is accomplished with a set of 40 TDCs sitting in the End-Of-Column region of the ASIC. Each TDC provides 9 channels per column. For the time-to-digital converter (TDC) a delay-locked-loop (DLL) approach is employed to achieve a constant time binning of 100ps. Simulation results show that an average rms time resolution of 33ps with a power consumption of the TDC better than 33 mW per column is achieved. This contribution will present the design, simulation results and implementation challenges of the TDC. © 2012 IOP Publishing Ltd and SISSA.
56367858
EXPERIMENTAL STUDY OF CRYSTAL CHANNELING AT CERN-SPS FOR BEAM-HALO CLEANING
An efficient and robust collimation system is mandatory for any superconducting hadron collider, in particular for the LHC, which will store a beam of unprecedented high intensity and energy. The usage of highly efficient and short primary bent-crystal collimators might be a possibility for reaching nominal and ultimate LHC intensity. Over the last years, groups in Italy (Ferrara) and Russia (St. Petersburg) have developed crystal production methods, that considerably improve the crystal quality. These developments led, in turn, to a surprising increase in the channeling efficiency and to the recent observation of the “volume reflection” mechanism. The aim of the proposed experiment is the setup of a beam test facility, directing primary protons from the SPS onto a bent silicon crystal, and the quantitative study of single-pass efficiency for all involved processes. Final goal will be the extrapolation of important information on the feasibility of a crystal collimator for halo cleaning in the LHC. The experiment will be performed in the H8 beamline at the CERN SPS where a beam with very small divergence can be provided thus representing a unique facility for tests and characterizationof crystals to be used forparticle channeling studies.
121126964
First observation of multiple volume reflection by different planes in one bent silicon crystal for high-energy protons
Abstract Multiple volume reflection by different planes in a bent silicon crystal with its 〈111〉 axis orientation close to the beam direction was observed for the first time for 400 GeV/ c protons at the CERN SPS. The proton beam was deflected to the side opposite to the crystal bend by an angle of about 67 μrad, which is five times larger than in a single volume reflection by the (110) bent planes. The registered efficiency of one side deflection was about 84%. It was shown that multiple volume reflection transforms to a single volume reflection when the orientation angle of the 〈111〉 axis relative to the beam direction is increased.