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.
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.
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.
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).
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.
110794312
Development of the ASICs for the NA62 pixel gigatracker
We present the ASIC development for the readout electronics of the Gigatracker pixel detector of NA62. Specifications of this detector are challenging in terms of timing precision with a hit time stamp accuracy of 100 ps and a peak hit rate of 50 Mhits/cm/s. A timing precision and hit rate are more than one order of magnitude faster than pixel LHC readout ASIC. The research for pixel cell design and the readout architectures are following two approaches, which are presented and discussed in this paper. Presently demonstrator prototypes are under development and SPICE simulation results of the frontend, the readout strategy and and the pixelcolumn are also presented and discussed.
122927860
Multiple volume reflections of high-energy protons in a sequence of bent silicon crystals assisted by volume capture
Abstract Multiple volume reflections of the 400 GeV / c proton beam by the sequence of fourteen bent silicon strips has been studied at the CERN SPS. The sequence is close to be parallel that is the spread of the strip orientation angles is much smaller than their bend angle and eleven strips working coherently in the regime of volume reflections deflected the beam by 110 μrad with the efficiency 88%, which is significantly larger than the estimation based on independent reflections. The mechanism giving the efficiency increase has been studied by simulation. It appears that many particles volume captured in one of the strips take part in volume reflections in the subsequent ones. Such a crystal multi reflector can be successfully used as a primary collimator for the beam halo collimation of high-energy accelerators.
121209661
The P326 (NA48/3) Gigatracker: Requirements and design concept
Abstract P326 aims at measuring the very rare decay K + → π + ν ν ¯ at the CERN SPS. The Gigatracker should track every particle of the 75 GeV / c hadron beam at a rate of about 1 GHz with time resolution in the 100 ps range and good momentum and angle resolution. The calculated fluence in 100 days of data taking is comparable to the one expected in the inner layers of the silicon trackers in LHC experiments during 10 years of operation. The physics requirements on the Gigatracker performance are overviewed and the preliminary design concept is outlined.
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.