117991978
Experimental Measurement of Channeling Phenomena
A short introduction on the physics of channeling and a detailed explanation of the experimental techniques used for the measurement of channeling and volume reflection phenomena are presented. Emphasis is placed on the experiment performed at the CERN SPS by the H8-RD22 Collaboration, which deflected a 400 GeV/c proton beam by means of a short bent silicon crystal with very high efficiency. A brief review of other channeling experiments is done focusing on the possible application of channeling for polarizing particle beams.
118676553
Experimental proposal to study the excess at Mjj=150 GeV presented by CDF at Fermilab
We propose an experimental test to verify the unexpected excess at Mjj=150GeV presented by the CDF collaboration in the invariant mass distribution of jet pairs produced in association with a W boson. 
We propose a formation experiment in which the energy range of the Mjj excess is scanned with proton-antiproton interactions at the Tevatron.
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.
110168648
The front end electronics of the NA62 Gigatracker: Challenges, design and experimental measurements
The beam spectrometer of the NA62 experiment consists of 3 Gigatracker (GTK) stations. Each station comprises a pixel detector of 16 cm 2 active area made of an assembly of 10 readout ASICs bump bonded to a 200 μ m thick pixel silicon sensor, comprising 18000 pixels of 300 μ m × 300 μ m . The main challenge of the NA62 pixel GTK station is the combination of an extremely high kaon/pion beam rate, where the intensity in the center of the beam reaches up to 1.5 Mhit s − 1 mm − 2 together with an extreme time resolution of 100 ps . To date, it is the first silicon tracking system with this time resolution. To face this challenge, the pixel analogue front end has been designed with a peaking time of 4 ns , with a planar silicon sensor operating up to 300 V over depletion. Moreover, the radiation level is severe, 2 × 10 14 1 MeV n e q . cm − 2 per year of operation. Easy replacement of the GTK stations is foreseen as a design requirement. The amount of material of a single station should also be less than 0.5% X 0 to minimize the background, which imposes strong constraints on the mechanics and the cooling system. We report upon the design and architecture of the 2 prototype demonstrator chips both designed in 130 nm CMOS technology, one with a constant fraction discriminator and the time stamp digitisation in each pixel (In-Pixel), and the other with a time-over-threshold discriminator and the processing of the time stamp located in the End of Column (EoC) region at the chip periphery. Some preliminary results are presented.
123184823
High-efficiency deflection of high-energy negative particles through axial channeling in a bent crystal
Abstract Deflection due to axial channeling in a silicon crystal bent along the 〈111〉 axis was observed for 150 GeV/ c negative particles, mainly π − mesons, at one of the secondary beams of the CERN SPS. The whole beam was deflected to one side with the efficiency of about 90% and with the peak position at the bend crystal angle α = 43 μrad . The deflection occurs mainly due to doughnut scattering of above-barrier particles by the atomic strings of the crystal. However, due to a high probability of particle recapture into bound states with the atomic strings their contribution to the deflection should be about 15% for our case according to simulation results.
122866398
The NA62 Gigatracker pixel detector system
The silicon tracker for the NA62 experiment has to provide both a time resolution of 150 ps rms and a space resolution of about 100 mu m rms. These challenging specifications require the development of a new readout electronics in order to address the problem of measuring the tracks arrival time with such a high channel density. Moreover, the high particle density (up to 1.5 MHz/mm(2) in the center and 0.8-1 GHz in total) requires a high speed measurement and data transmission in order to keep the dead time below 1%. (C) 2009 Elsevier B.V. All rights reserved.
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.
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.
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.