Roberto Messi - Academia.edu (original) (raw)

Papers by Roberto Messi

Sensors

LIDAL (Light Ion Detector for ALTEA, Anomalous Long-Term Effects on Astronauts) is a radiation de... more LIDAL (Light Ion Detector for ALTEA, Anomalous Long-Term Effects on Astronauts) is a radiation detector designed to measure the flux, the energy spectra and, for the first time, the time-of-flight of ions in a space habitat. It features a combination of striped silicon sensors for the measurement of deposited energy (using the ALTEA device, which operated from 2006 to 2012 in the International Space Station) and fast scintillators for the time-of-flight measurement. LIDAL was tested and calibrated using the proton beam line at TIFPA (Trento Institute for Fundamental Physics Application) and the carbon beam line at CNAO (National Center for Oncology Hadron-therapy) in 2019. The performance of the time-of-flight system featured a time resolution (sigma) less than 100 ps. Here, we describe the detector and the results of these tests, providing ground calibration curves along with the methodology established for processing the detector’s data. LIDAL was uploaded in the International Spa...

CERN-LHC. Decays of b hadrons into final states containing a D0 meson and a muon are used to meas... more CERN-LHC. Decays of b hadrons into final states containing a D0 meson and a muon are used to measure the bbbar production cross-section. The average cross-section to produce b-flavoured or bbar-flavoured hadrons is measured in different pseudorapidity intervals over the entire range of pT assuming the LEP (and Tevatron) fractions for fragmentation into b-flavoured hadrons. Note that since the publication of this paper, LHCb measurements of the b-fractions have shown that the Tevatron b-fractions are correct (see http://arxiv.org/abs/1111.2357) and therefore should be used in preference to the LEP ones. This record lists both for completeness.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1998

The performance of a prototype drift chamber operating in a He-based gas mixture as a specific io... more The performance of a prototype drift chamber operating in a He-based gas mixture as a specific ionisation detector is presented. In spite of the small number of primary ions, Helium performs quite satisfactorily in measuring energy losses for charged particles: with 50GeV/c pions, we have measured in a 90%He–10%iC4H10 mixture a relative energy loss resolution of 3.1% with 75 samples

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1998

The main goal of the KLOE experiment is the study of CP violation in the K mesons system, with an... more The main goal of the KLOE experiment is the study of CP violation in the K mesons system, with an accuracy of 10−4 in the measurement of Re(ε′ε). This task imposes strong constraints on the design and operation of the drift chamber, which must reconstruct the charged decays of low momentum KL's and KS's with high efficiency and high resolution.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1998

A tile calorimeter (QCAL) has been designed for the KLOE experiment. Optimization studies have be... more A tile calorimeter (QCAL) has been designed for the KLOE experiment. Optimization studies have been conducted by testing the coupling between different types of scintillators and WLS fibers. Results on light yield, attenuation length of fibers and time resolution are presented.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2000

RPCs are strong candidates for the outer regions of the LHCb muon detector. We have tested single... more RPCs are strong candidates for the outer regions of the LHCb muon detector. We have tested single-gap and dual-gap detectors built with low-resistivity phenolic plates (ρ = 9 • 10 9 Ωcm) and operated in avalanche mode. Measurements have been performed over a wide range of beam intensities and on the GIF at CERN. The results are presented and discussed, with special emphasis on the detection efficiency.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2018

LIDAL (Light Ion Detector for ALTEA system) is a compact detector designed to upgrade ALTEA (Anom... more LIDAL (Light Ion Detector for ALTEA system) is a compact detector designed to upgrade ALTEA (Anomalous Long Term Effects on Astronauts) silicon detector apparatus, in order to study in detail the low-Z part of ions spectrum inside the International Space Station (ISS) and to enhance the Particle Identification (PID) capability of the system. The new detector is designed to trigger ALTEA and to perform Time-Of-Flight measurements. It is based on plastic scintillators for fast timing applications read by Photo-Multiplier-Tubes (PMTs). A custom Front End Electronics (FEE) has been designed to reach time resolutions less than 100 ps () for protons. A LIDAL prototype has been developed at the University of Rome Tor Vergata to test the timing performance of the scintillators, the PMTs and of the custom FEE using the proton beam line at the TIFPA (Trento Institute for Fundamentals Physics Applications) center in Trento, Italy. The results of these tests are reported and discussed. They have also been used for a preliminary evaluation of the Particle Identification (PID) capability of the final LIDAL-ALTEA detector system in response to the ions spectra expected on-board the ISS.

Summary. — In this work we describe the results of performance tests and mea-sures of SiPM of sev... more Summary. — In this work we describe the results of performance tests and mea-sures of SiPM of several sizes (1 ∗ 1, 3 ∗ 3, 5 ∗ 5) delivered from MEPHI. The SiPMs have been studied both in steady and pulsed stimuli. Aging and temperature be-havior are also discussed. Another test have been performed in order to obtain an electrical model of the SiPM to be used in analog simulations. Finally, a design of a pilot chip with 0.35µm technology implementing a front-end for SiPM aimed to TOF applications with adjustable thresholds and very high dynamical range is described. PACS 07.87.+v – Spaceborne and space research instrument. PACS 95.55.Aq – Charge-coupled devices, image detectors, and IR detector arrays. PACS 85.30.De – Semiconductor-device characterization, design, and modeling.

Astronomy and Astrophysics

Journal of Physics: Conference Series, 2019

The LIDAL (Light Ion Detector for ALTEA) is a device designed to work paired with three silicon d... more The LIDAL (Light Ion Detector for ALTEA) is a device designed to work paired with three silicon detector units of ALTEA (Anomalous Long Term Effects on Astronauts) in order to improve the particle identification capabilities of ALTEA on the International Space Station also providing Time-of-Flight measurements. The LIDAL-ALTEA goal is to measure ions from protons up to iron in real time. The improved measurements of the radiation environment inside ISS will be very valuable for radiation risk assessment and mitigation. It is necessary to have a detailed simulation of the apparatus response to cosmic ray nuclei in order to assess the detector response, its observational capabilities and to set the relevant parameters of the device. Here a new Monte Carlo simulation of the LIDAL-ALTEA setup and physics processes, in the framework of FLUKA, is presented. A comparison between Monte Carlo simulations and calibration data is also shown.

IEEE Transactions on Nanotechnology, 2018

Single walled carbon nanotube (SWCNT) ultrathin films were deposited on n doped Si substrates pro... more Single walled carbon nanotube (SWCNT) ultrathin films were deposited on n doped Si substrates provided with three electrodes for photoconductive measurements. Without illumination the devices show good rectifier properties and holes mobility in the range 10 5 cm/V•s which makes very promising for fast switching applications. Measuring the current voltage characteristics of the SWCNT film under illumination, an increase in the device performance is observed when a voltage V G is applied to the third electrode. In particular, increasing V G towards the breakdown region, an increase of more than 10 times is recorded in the photocurrent and in the external quantum efficiency with respect to the values measured at V G =0. The experimental data are interpreted considering a hole doping of the SWCNT film by the action of the third electrode voltage V G. Index Terms-carbon nanotubes, photodetector, voltage doping, three terminals devices, photoconductive devices I. INTRODUCTION Single walled carbon nanotube (SWCNT) thin films have been successfully considered for many applications as transistors,[1] gas sensors,[2] bolometers,[3] solar cells[4,5] and photodetectors.[6] Particular interest has been shown for light sensitive devices consisting of heterojunctions formed when a SWCNT thin film is deposited on the surface of a semiconductor, mainly n-doped Si.[7-9] In this case, the SWCNT thin film mainly plays the role of conductive semitransparent electrode collecting the charge generated inside the

The contributions of the IFSI to the Gornergrat Observatory in Switzerland with its 1.5 m infrare... more The contributions of the IFSI to the Gornergrat Observatory in Switzerland with its 1.5 m infrared telescope include a wobbling secondary mirror system and the multiple interface at the focal plane which houses four different photometers. The wobbling secondary mirror system has been built to modulate the signal. The system mechanics are, in principle, similar to a design developed at the University College of London. The system was optimized to minimize spurious vibrations. The mirror is actuated by two vibrators. The vibrators torque can be experimentally adjusted to balance the mirror torque. The mirror position is sensed by a magnetoresistance device and a servo loop is employed to drive the system. The multiple interface was designed in order to observe an astronomical object, during the same night, by means of up to four different spectrophotometers covering the wavelength range from UV to 30 microns.

The Astrophysical Journal, 1981

ABSTRACT

... P R. Barbosa Marinho, I. Bediaga, G. Cernicchiaro, A. Franca Barbosa, J. Magnin, J. Marques d... more ... P R. Barbosa Marinho, I. Bediaga, G. Cernicchiaro, A. Franca Barbosa, J. Magnin, J. Marques de Miranda, A. Massafferri, A. Reis, R. Silva, S. Amato, P. Colrain, T. Da Silva, JR T. De Mello-Neto, L. De Paula, M. Gandelman, J H. Lopes, B. Marechal, D. Moraes, E. Polycarpo, Z ...

The purpose of this work is to study the characteristics of the Silicon Photomultiplier (SiPM) an... more The purpose of this work is to study the characteristics of the Silicon Photomultiplier (SiPM) and its applications in the detection of charged particles. The SiPM is an array of independent avalanche photodiodes (APD) operating in the Geiger region mode. A new experimental ...

Since the discovery of the Lambda(1405)\Lambda(1405)Lambda(1405), it remains poorly described by conventional constitue... more Since the discovery of the Lambda(1405)\Lambda(1405)Lambda(1405), it remains poorly described by conventional constituent quark models, and it is a candidate for having an "exotic" meson-baryon or "penta-quark" structure, similar to states recently reported in the hidden charm sector. The Lambda(1405)\Lambda(1405)Lambda(1405) can be produced in the reaction gammaprightarrowK+Lambda(1405)\gamma p \rightarrow K^+\Lambda(1405)gammaprightarrowK+Lambda(1405). The pure I=0 decay mode into Sigma0pi0\Sigma^0\pi^0Sigma0pi0 is prohibited for the mass-overlapping Sigma(1385)\Sigma(1385)Sigma(1385). Combining a large aperture forward magnetic spectrometer and a central BGO crystal calorimeter, the BGO-OD experiment is ideally suited to measure this decay with the K+K^+K+ in the forward direction. Preliminary results are presented. *Supported by DFG (PN 388979758, 405882627).

EPJ Web of Conferences, 2020

The unexpected nodal structure of the beam asymmetry recently reported by the GRAAL collaboration... more The unexpected nodal structure of the beam asymmetry recently reported by the GRAAL collaboration in η′ photoproduction very close to threshold could be explained by a previously unobserved narrow resonance. The BGO-OD experiment is ideally suited to verify this measurement via the detection of forward going charged particles which in the threshold region of interest allows the identification of the reaction γp → η′ p solely based on the proton going in the forward direction. This yields unprecedented statistics if, in the missing mass analysis of the η′ meson, the background can be sufficiently well controlled. Preliminary results using a linearly polarised photon beam are shown. The reaction γp → η′ p was identified in the BGO forward spectrometer, with simulated data used to seperate signal and background.

Sensors

LIDAL (Light Ion Detector for ALTEA, Anomalous Long-Term Effects on Astronauts) is a radiation de... more LIDAL (Light Ion Detector for ALTEA, Anomalous Long-Term Effects on Astronauts) is a radiation detector designed to measure the flux, the energy spectra and, for the first time, the time-of-flight of ions in a space habitat. It features a combination of striped silicon sensors for the measurement of deposited energy (using the ALTEA device, which operated from 2006 to 2012 in the International Space Station) and fast scintillators for the time-of-flight measurement. LIDAL was tested and calibrated using the proton beam line at TIFPA (Trento Institute for Fundamental Physics Application) and the carbon beam line at CNAO (National Center for Oncology Hadron-therapy) in 2019. The performance of the time-of-flight system featured a time resolution (sigma) less than 100 ps. Here, we describe the detector and the results of these tests, providing ground calibration curves along with the methodology established for processing the detector’s data. LIDAL was uploaded in the International Spa...

CERN-LHC. Decays of b hadrons into final states containing a D0 meson and a muon are used to meas... more CERN-LHC. Decays of b hadrons into final states containing a D0 meson and a muon are used to measure the bbbar production cross-section. The average cross-section to produce b-flavoured or bbar-flavoured hadrons is measured in different pseudorapidity intervals over the entire range of pT assuming the LEP (and Tevatron) fractions for fragmentation into b-flavoured hadrons. Note that since the publication of this paper, LHCb measurements of the b-fractions have shown that the Tevatron b-fractions are correct (see http://arxiv.org/abs/1111.2357) and therefore should be used in preference to the LEP ones. This record lists both for completeness.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1998

The performance of a prototype drift chamber operating in a He-based gas mixture as a specific io... more The performance of a prototype drift chamber operating in a He-based gas mixture as a specific ionisation detector is presented. In spite of the small number of primary ions, Helium performs quite satisfactorily in measuring energy losses for charged particles: with 50GeV/c pions, we have measured in a 90%He–10%iC4H10 mixture a relative energy loss resolution of 3.1% with 75 samples

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1998

The main goal of the KLOE experiment is the study of CP violation in the K mesons system, with an... more The main goal of the KLOE experiment is the study of CP violation in the K mesons system, with an accuracy of 10−4 in the measurement of Re(ε′ε). This task imposes strong constraints on the design and operation of the drift chamber, which must reconstruct the charged decays of low momentum KL's and KS's with high efficiency and high resolution.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1998

A tile calorimeter (QCAL) has been designed for the KLOE experiment. Optimization studies have be... more A tile calorimeter (QCAL) has been designed for the KLOE experiment. Optimization studies have been conducted by testing the coupling between different types of scintillators and WLS fibers. Results on light yield, attenuation length of fibers and time resolution are presented.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2000

RPCs are strong candidates for the outer regions of the LHCb muon detector. We have tested single... more RPCs are strong candidates for the outer regions of the LHCb muon detector. We have tested single-gap and dual-gap detectors built with low-resistivity phenolic plates (ρ = 9 • 10 9 Ωcm) and operated in avalanche mode. Measurements have been performed over a wide range of beam intensities and on the GIF at CERN. The results are presented and discussed, with special emphasis on the detection efficiency.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2018

LIDAL (Light Ion Detector for ALTEA system) is a compact detector designed to upgrade ALTEA (Anom... more LIDAL (Light Ion Detector for ALTEA system) is a compact detector designed to upgrade ALTEA (Anomalous Long Term Effects on Astronauts) silicon detector apparatus, in order to study in detail the low-Z part of ions spectrum inside the International Space Station (ISS) and to enhance the Particle Identification (PID) capability of the system. The new detector is designed to trigger ALTEA and to perform Time-Of-Flight measurements. It is based on plastic scintillators for fast timing applications read by Photo-Multiplier-Tubes (PMTs). A custom Front End Electronics (FEE) has been designed to reach time resolutions less than 100 ps () for protons. A LIDAL prototype has been developed at the University of Rome Tor Vergata to test the timing performance of the scintillators, the PMTs and of the custom FEE using the proton beam line at the TIFPA (Trento Institute for Fundamentals Physics Applications) center in Trento, Italy. The results of these tests are reported and discussed. They have also been used for a preliminary evaluation of the Particle Identification (PID) capability of the final LIDAL-ALTEA detector system in response to the ions spectra expected on-board the ISS.

Summary. — In this work we describe the results of performance tests and mea-sures of SiPM of sev... more Summary. — In this work we describe the results of performance tests and mea-sures of SiPM of several sizes (1 ∗ 1, 3 ∗ 3, 5 ∗ 5) delivered from MEPHI. The SiPMs have been studied both in steady and pulsed stimuli. Aging and temperature be-havior are also discussed. Another test have been performed in order to obtain an electrical model of the SiPM to be used in analog simulations. Finally, a design of a pilot chip with 0.35µm technology implementing a front-end for SiPM aimed to TOF applications with adjustable thresholds and very high dynamical range is described. PACS 07.87.+v – Spaceborne and space research instrument. PACS 95.55.Aq – Charge-coupled devices, image detectors, and IR detector arrays. PACS 85.30.De – Semiconductor-device characterization, design, and modeling.

Astronomy and Astrophysics

Journal of Physics: Conference Series, 2019

The LIDAL (Light Ion Detector for ALTEA) is a device designed to work paired with three silicon d... more The LIDAL (Light Ion Detector for ALTEA) is a device designed to work paired with three silicon detector units of ALTEA (Anomalous Long Term Effects on Astronauts) in order to improve the particle identification capabilities of ALTEA on the International Space Station also providing Time-of-Flight measurements. The LIDAL-ALTEA goal is to measure ions from protons up to iron in real time. The improved measurements of the radiation environment inside ISS will be very valuable for radiation risk assessment and mitigation. It is necessary to have a detailed simulation of the apparatus response to cosmic ray nuclei in order to assess the detector response, its observational capabilities and to set the relevant parameters of the device. Here a new Monte Carlo simulation of the LIDAL-ALTEA setup and physics processes, in the framework of FLUKA, is presented. A comparison between Monte Carlo simulations and calibration data is also shown.

IEEE Transactions on Nanotechnology, 2018

Single walled carbon nanotube (SWCNT) ultrathin films were deposited on n doped Si substrates pro... more Single walled carbon nanotube (SWCNT) ultrathin films were deposited on n doped Si substrates provided with three electrodes for photoconductive measurements. Without illumination the devices show good rectifier properties and holes mobility in the range 10 5 cm/V•s which makes very promising for fast switching applications. Measuring the current voltage characteristics of the SWCNT film under illumination, an increase in the device performance is observed when a voltage V G is applied to the third electrode. In particular, increasing V G towards the breakdown region, an increase of more than 10 times is recorded in the photocurrent and in the external quantum efficiency with respect to the values measured at V G =0. The experimental data are interpreted considering a hole doping of the SWCNT film by the action of the third electrode voltage V G. Index Terms-carbon nanotubes, photodetector, voltage doping, three terminals devices, photoconductive devices I. INTRODUCTION Single walled carbon nanotube (SWCNT) thin films have been successfully considered for many applications as transistors,[1] gas sensors,[2] bolometers,[3] solar cells[4,5] and photodetectors.[6] Particular interest has been shown for light sensitive devices consisting of heterojunctions formed when a SWCNT thin film is deposited on the surface of a semiconductor, mainly n-doped Si.[7-9] In this case, the SWCNT thin film mainly plays the role of conductive semitransparent electrode collecting the charge generated inside the

The contributions of the IFSI to the Gornergrat Observatory in Switzerland with its 1.5 m infrare... more The contributions of the IFSI to the Gornergrat Observatory in Switzerland with its 1.5 m infrared telescope include a wobbling secondary mirror system and the multiple interface at the focal plane which houses four different photometers. The wobbling secondary mirror system has been built to modulate the signal. The system mechanics are, in principle, similar to a design developed at the University College of London. The system was optimized to minimize spurious vibrations. The mirror is actuated by two vibrators. The vibrators torque can be experimentally adjusted to balance the mirror torque. The mirror position is sensed by a magnetoresistance device and a servo loop is employed to drive the system. The multiple interface was designed in order to observe an astronomical object, during the same night, by means of up to four different spectrophotometers covering the wavelength range from UV to 30 microns.

The Astrophysical Journal, 1981

ABSTRACT

... P R. Barbosa Marinho, I. Bediaga, G. Cernicchiaro, A. Franca Barbosa, J. Magnin, J. Marques d... more ... P R. Barbosa Marinho, I. Bediaga, G. Cernicchiaro, A. Franca Barbosa, J. Magnin, J. Marques de Miranda, A. Massafferri, A. Reis, R. Silva, S. Amato, P. Colrain, T. Da Silva, JR T. De Mello-Neto, L. De Paula, M. Gandelman, J H. Lopes, B. Marechal, D. Moraes, E. Polycarpo, Z ...

The purpose of this work is to study the characteristics of the Silicon Photomultiplier (SiPM) an... more The purpose of this work is to study the characteristics of the Silicon Photomultiplier (SiPM) and its applications in the detection of charged particles. The SiPM is an array of independent avalanche photodiodes (APD) operating in the Geiger region mode. A new experimental ...

Since the discovery of the Lambda(1405)\Lambda(1405)Lambda(1405), it remains poorly described by conventional constitue... more Since the discovery of the Lambda(1405)\Lambda(1405)Lambda(1405), it remains poorly described by conventional constituent quark models, and it is a candidate for having an "exotic" meson-baryon or "penta-quark" structure, similar to states recently reported in the hidden charm sector. The Lambda(1405)\Lambda(1405)Lambda(1405) can be produced in the reaction gammaprightarrowK+Lambda(1405)\gamma p \rightarrow K^+\Lambda(1405)gammaprightarrowK+Lambda(1405). The pure I=0 decay mode into Sigma0pi0\Sigma^0\pi^0Sigma0pi0 is prohibited for the mass-overlapping Sigma(1385)\Sigma(1385)Sigma(1385). Combining a large aperture forward magnetic spectrometer and a central BGO crystal calorimeter, the BGO-OD experiment is ideally suited to measure this decay with the K+K^+K+ in the forward direction. Preliminary results are presented. *Supported by DFG (PN 388979758, 405882627).

EPJ Web of Conferences, 2020

The unexpected nodal structure of the beam asymmetry recently reported by the GRAAL collaboration... more The unexpected nodal structure of the beam asymmetry recently reported by the GRAAL collaboration in η′ photoproduction very close to threshold could be explained by a previously unobserved narrow resonance. The BGO-OD experiment is ideally suited to verify this measurement via the detection of forward going charged particles which in the threshold region of interest allows the identification of the reaction γp → η′ p solely based on the proton going in the forward direction. This yields unprecedented statistics if, in the missing mass analysis of the η′ meson, the background can be sufficiently well controlled. Preliminary results using a linearly polarised photon beam are shown. The reaction γp → η′ p was identified in the BGO forward spectrometer, with simulated data used to seperate signal and background.