Search

Your search keyword '"R. Iommi"' showing total 6 results
Start Over Author "R. Iommi"
6 results on '"R. Iommi"'

1. Study of an active predistorter suitable for MMIC implementation

Author

M. Pagani, A. Meazza, R. Iommi, and Giuseppe Macchiarella

Subjects
Signal processing, Engineering, Radiation, business.industry, Amplifier, Circuit design, Condensed Matter Physics, Predistortion, Linearizer, Electronic engineering, Electrical and Electronic Engineering, business, Dimensioning, Monolithic microwave integrated circuit, Intermodulation
Abstract

A linearizer architecture, based on predistortion and well suited for monolithic-microwave integrated-circuit (MMIC) implementation is presented in this paper. A mathematical model for the linearizer is described, which allows an optimum choice of the various design parameters (taking into account several constraints due to the specific implementation environment). The power amplifier to be linearized is described by nonlinear functions experimentally derivable from large signal S-parameters; the mathematical model is based on the complex power series expansion of these functions and on the definition of a suitable scaling rule illustrated in this paper. The overall linearizer model has been implemented in a system simulator (working with complex signals), also allowing the investigation of second-order distortion effects (not taken into account during the dimensioning of the structure). A preliminary prototype of the linearizer operating in the 12-16-GHz band has been implemented as a MMIC device (GaAs 0.25-/spl mu/m technology); the measured performances have confirmed the promising potential of the novel architecture introduced.

Published
2005
Full Text
View/download PDF

2. Light-weight spherical mirrors for Cherenkov detectors

Author

R. Crateri, Maurizio Lucentini, E. Nappi, G. M. Urciuoli, Fabio Santavenere, S. Frullani, L. Pierangeli, P. Vernin, R. Fratoni, S. Colilli, M. Gricia, F. Garibaldi, F. Cusanno, A. Braem, Mauro Iodice, E. Cisbani, A. Mostarda, L. Lagamba, R. De Leo, Fausto Giuliani, and R. Iommi

Subjects
Physics, Nuclear and High Energy Physics, Spectrometer, Physics::Instrumentation and Detectors, business.industry, Cherenkov detector, Curved mirror, Particle detector, Radiation length, law.invention, Optics, law, Honeycomb, Neutron detection, Optoelectronics, business, Instrumentation, Cherenkov radiation
Abstract

Light-weight spherical mirrors have been appositely designed and built for the gas threshold Cherenkov detectors of the two Hall A spectrometers. The mirrors are made of a 1mm thick aluminized plexiglass sheet, reinforced by a rigid backing consisting of a phenolic honeycomb sandwiched between two carbon fiber mats epoxy glued. The produced mirrors have a thickness equivalent to 0.55% of radiation length, and an optical slope error of about 5.5mrad. These characteristics make these mirrors suitable for the implementation in Cherenkov threshold detectors. Ways to improve the mirror features are also discussed in view of their possible employment in RICH detectors.

Published
2003
Full Text
View/download PDF

3. Silica aerogel threshold Cherenkov counters for the JLab Hall A spectrometers: improvements and proposed modifications

Author

Salvatore Frullani, A. Mostarda, S. Colilli, Guido M. Urciuoli, Evaristo Cisbani, Fabio Santavenere, M. Gricia, R. Iommi, L. Pierangeli, Antonio Leone, M. Iodice, Franco Garibaldi, L. Lagamba, Roberto Perrino, R. Crateri, E. Nappi, R. De Leo, Maurizio Lucentini, and Fausto Giuliani

Subjects
Physics, Nuclear and High Energy Physics, Photomultiplier, Photon, Spectrometer, Physics::Instrumentation and Detectors, business.industry, Cherenkov detector, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Particle detector, Particle identification, law.invention, Nuclear physics, Optics, law, Nuclear Experiment, business, Instrumentation, Cherenkov radiation
Abstract

Recently approved experiments at Jefferson Lab Hall A require a clean kaon identification in a large electron, pion, and proton background environment. To this end, improved performance is required of the silica aerogel threshold Cherenkov counters installed in the focal plane of the two Hall A spectrometers. In this paper we propose two strategies to improve the performance of the Cherenkov counters which presently use a hydrophilic aerogel radiator, and convey Cherenkov photons towards the photomultipliers by means of mirrors with a parabolic shape in one direction and flat in the other. The first strategy is aerogel baking. In the second strategy we propose a modification of the counter geometry by replacing the mirrors with a planar diffusing surface and by displacing in a different way the photomultipliers. Tests at CERN with a 5GeV/c multiparticle beam revealed that both the strategies are able to increase significantly the number of the detected Cherenkov photons and, therefore, the detector performance.

Published
2001
Full Text
View/download PDF

4. Optimization of compact gamma cameras for breast imaging

Author

M.N. Cinti, Raffaele Scafè, Luca Indovina, F. Cusanno, Franco Garibaldi, Rosanna Pellegrini, G. Trotta, R. Iommi, Evaristo Cisbani, G. M. Urciuoli, and Roberto Pani

Subjects
Physics, Position sensitive photomultiplier, Nuclear and High Energy Physics, medicine.medical_specialty, business.industry, Breast imaging, Detector, computer.software_genre, Simulation software, Optics, medicine, Medical physics, business, Instrumentation, computer
Abstract

Mammoscintigraphy is an important tool for secondary breast cancer screening. Good results have been achieved with dedicated gamma cameras for T 1b tumors (size >5 mm). We have performed simulations and measurements in order to improve the performance of compact gamma cameras for detecting T 1a tumors (size 3 ) coupled with a Position Sensitive Photomultiplier Tube (PSPMT) having a multianode structure (2×2 mm 2 pad size). Measurements allowed to test the validity of the simulation software.

Published
2001
Full Text
View/download PDF

5. Performances of the aerogel threshold Cherenkov counter for the Jefferson Lab Hall A spectrometers in the 1–4 GeV/c momentum range

Author

A. Leone, R. Crateri, G. M. Urciuoli, Fausto Giuliani, A. Mostarda, Roberto Perrino, L. Lagamba, S. Colilli, Franco Garibaldi, E. Cisbani, M. Gricia, Fabio Santavenere, R. De Leo, Salvatore Frullani, L. Pierangeli, M. Iodice, E. Nappi, Maurizio Lucentini, and R. Iommi

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Range (particle radiation), Large Hadron Collider, Spectrometer, Proton, Physics::Instrumentation and Detectors, Cherenkov detector, Astrophysics::High Energy Astrophysical Phenomena, law.invention, Nuclear physics, Momentum, Pion, law, Physics::Accelerator Physics, High Energy Physics::Experiment, Nuclear Experiment, Instrumentation, Cherenkov radiation
Abstract

The silica aerogel threshold Cherenkov counter for the Jefferson Lab Hall A spectrometer was tested at CERN with a mixed beam of positrons, pions, and protons in the 1–4 GeV/ c momentum range. Aerogel from Airglass, Sweden, with a refractive index of 1.025 was used. For this momentum range and refractive index only positrons and pions are above the Cherenkov threshold. Detection efficiencies of 96% for pions and of 98% for positrons were measured. A 5% fake proton detection was also measured, mostly caused by induced δ-rays and accidentals generated by high counting rates.

Published
2001
Full Text
View/download PDF

6. Basic instrumentation for Hall A at Jefferson Lab

Author

T. Pussieux, Paul Souder, J. H. Mitchell, Y. Roblin, O. Ravel, E. Chudakov, K. A. Griffioen, C. Cavata, J. A. Templon, H. F. Ibrahim, J. S. McCarthy, M. A. Stevens, D. P. Watts, B. Frois, W. J. Schneider, Dipangkar Dutta, R. Di Salvo, R. I. Pomatsalyuk, A. Soldi, G. J. Kumbartzki, Arijit Saha, N. Colombel, J. Berthot, Jing Zhao, A. J. Sarty, B. D. Anderson, J. Martine, M. Coman, R. Michaels, M. B. Epstein, R. W. Lourie, J. O. Hansen, N. Degrande, J. Mclntyre, John Arrington, L. Zhu, W. Kahl, Bogdan Wojtsekhowski, P. Djawotho, M. Leuschner, William Bertozzi, K. A. Aniol, A. Gasparian, Karl Slifer, Jrm Annand, C. F. Perdrisat, D. Pripstein, M. Baylac, S. Kox, X. Jiang, K. Kramer, H. Breuer, David Hamilton, Jian-Ping Chen, T. Averett, L. B. Auerbach, G. A. Rutledge, G. Quéméner, Stephanie Escoffier, P.Y. Bertin, R. Suleiman, R. Carr, Pete Markowitz, A. Deur, Z. Papandreou, R. L. Walter, R. D. McKeown, T. P. Gorringe, M. Rvachev, R. Holmes, S. Churchwell, J. Marroncle, S. Platchkov, M. Khandaker, M. Liang, L. Pierangeli, K. Kino, A. Ketikyan, Kevin Fissum, F. W. Hersman, J. LeRose, F. Giuliani, P. E. Ulmer, Roberto Perrino, R. De Leo, J. Gao, L. A. Ewell, S. Jensen, R. Crateri, Shalev Gilad, C. W. de Jager, D. Lhuillier, J.E. Ducret, M. Gricia, R. Iommi, F. Sabatavenere, P. A. Zolnierczuk, K. Wijesooriya, Alan M. Nathan, D. Rowntree, E. Voutier, H. Holmgren, S. K. Nanda, D. G. Meekins, K. S. Egiyan, C. R. Howell, A. Serdarevic-Offermann, Hiroaki Tsubota, D. G. Zainea, J. R. Calarco, S. Esp, T. Terasawa, Vincent Breton, C. C. Chang, J. Domingo, T. Black, A. T. Katramatou, S. Kerhoas, F. Santavenere, J. Y. Mougey, R. Van de Vyver, G. M. Urciuoli, Seigo Kato, G. M. Huber, B. Reitz, E. J. Beise, K. S. Kumar, F. Garibaldi, Pavel Sorokin, G. J. Lolos, M. Lucentini, J. Segal, H. Xiang, D. V. Boykin, W. U. Boeglin, C. Glashausser, E. Cisbani, A. Leone, R. D. Ransomez, Gordon D. Cates, Sonja Dieterich, H. Voskanyan, C. Jutier, R. L.J. van der Meer, Olivier Gayou, James A. Miller, L. Van Hoorebeke, Sebastien Incerti, J. Jardillier, L. Cardman, James J. Kelly, F. Xiong, S. Jaminion, I. K. Kominis, K. McCormick, P. Vernin, P. M. Rutt, A. Petrosyan, David L. Prout, Nilanga Liyanage, L. Lagamba, X. Zheng, S. L. Spiegel, Branislav Vlahovic, Leonid Levchuk, Mauro Iodice, Larry Weinstein, F. Marie, D. G. Ireland, N. S. Chant, David Manley, V. A. Punjabi, C. E. Jones, J. Gomez, Wolfgang Korsch, W. Xu, J. W. Watson, M. Roedelbronn, F. T. Baker, Z. E. Meziani, T. Saito, S. Frullani, H. Ueno, E. J. Brash, R. Roche, E. Hovhannisyan, C. E. Hyde-Wright, N. d'Hose, L. Bimbot, G. Laveissière, R. Madey, Kazushige Maeda, A. Gavalya, W. Miller, D. Neyret, T. P. Smith, B. Diederich, E. Burtin, M. Holtrop, L. Todor, G. Dezern, Z. L. Zhou, K. Livingston, D. S. Dale, V. Zeps, S. Mayilyan, E. Folts, B. D. Milbrath, Haiyan Gao, J. M. Finn, O. Rondon-Aramayo, R. A. Lindgren, V. Gorbenko, A. V. Glamazdin, Z. Chai, E. A.J.M. Offermann, S. Malov, J. Alcorn, S. Strauch, A. Shahinyan, G. Rosner, H. Fonvieille, P. G. Roos, E. W. Hughes, K. Joo, D. S. Brown, P. Brindza, G. G. Petratos, S. van Verst, M. Khayat, S. Colilli, Douglas Higinbotham, M. K. Jones, D. J. Margaziotis, M. Kuss, Seonho Choi, Ronald Gilman, Thomas Jefferson National Accelerator Facility (Jefferson Lab), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), HALL A, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Spectrometer, 010308 nuclear & particles physics, Cryogenics, Scintillator, 7. Clean energy, 01 natural sciences, Particle identification, Magnetic field, Nuclear physics, Cardinal point, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Nuclear Experiment, 010306 general physics, Nucleon, Instrumentation, Cherenkov radiation
Abstract

The instrumentation in Hall A at the Thomas Jefferson National Accelerator Facility was designed to study electro-and photo-induced reactions at very high luminosity and good momentum and angular resolution for at least one of the reaction products. The central components of Hall A are two identical high resolution spectrometers, which allow the vertical drift chambers in the focal plane to provide a momentum resolution of better than 2 x 10(-4). A variety of Cherenkov counters, scintillators and lead-glass calorimeters provide excellent particle identification. The facility has been operated successfully at a luminosity well in excess of 10(38) CM-2 s(-1). The research program is aimed at a variety of subjects, including nucleon structure functions, nucleon form factors and properties of the nuclear medium. (C) 2003 Elsevier B.V. All rights reserved.

Published
2004
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results