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.
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.
55051548
Characterization of Crystals for Steering of Protons through Channelling in Hadronic Accelerators
Channeling of relativistic particles through a crystal may be useful for many applications in accelerators, and particularly for collimation in hadronic colliders. Efficiency proved to be dependent on the state of the crystal surface and hence on the method used for preparation. We investigated the morphology and structure of the surface of the samples that have been used in accelerators with high efficiency. We found that crystal fabrication by only mechanical methods (dicing, lapping, and others) leads to a superficial damaged layer, which is correlated to performance limitation in accelerators. A planar chemical etching was studied and applied in order to remove the superficial damaged layer. RBS channeling analysis with low-energy protons and 4 He + highlighted better crystal perfection at surface, as a result of the etching. A protocol for preparation and characterization of crystal for channelling has been developed, which may be of interest for reliable operation with crystals in accelerators.
49541949
Polarization of a stored beam by spin filtering
The PAX Collaboration has successfully performed a spin-filtering experiment with protons at the COSY-ring. The measurement allowed the determination of the spin-dependent polarizing cross section, ...
109328792
READOUT ELECTRONICS OF THE NA62 GIGATRACKER SYSTEM
A crucial detector of the NA62 experiment is the beam spectrometer named Gigatracker. It consists of three stations of hybrid silicon pixels sensors with 150 ps (rms) of time resolution and 100 μm (rms) of space resolution. In addition the system operates under a high radiation environment and a high density of particles (up to 1.5 MHz/mm in the centre and 0.8 1 GHz in total). To meet these requirements the readout electronics must compensate the discriminators time-walk and the dead time should be below 1%. In order to evaluate the best solution, two readout chips have been developed. One is based on the constant-fraction discriminator technique and the other one is based on the use of a time-over-threshold circuit. The global architectures of both the front-end ASIC will be discussed.
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.
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).
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.