The modeled performance of the Alpha Magnetic Spectrometer (AMS) as a high-energy (0.3 to 100 GeV) gamma-ray detector is described, and its gamma-ray astrophysics objectives are discussed.
The Cherenkov Telescope Array (CTA) will be the next generation of ground-based observatory of very high energy gamma ray sources. The Italian Institute of Nuclear Physics (INFN) is involved in the ...R&D effort for the development of a possible solution for one of the Cherenkov photon camera designs, working on replacing the Hamamatsu MPPC S12642-0404PA-50 with more UV sensitive ones from Fondazione Bruno Kessler (FBK). INFN is currently developing the preamplifiers and the carrier boards for the SiPM chips that interface with the mechanics of the camera. To test the feasibility and the performance of SiPM cameras, a focal plane camera prototype module, upgraded with High Density NUV - SiPMs, produced by FBK, with a micro cell of 30 μm x 30 μm and 6 mm x 6 mm area, is being assembled. In this work, we describe the SiPM carrier boards, the assembly process and the qualification tests performed, before and after assembly, on the focal plane modules to qualify the procedures.
Substantial fluxes of protons and leptons with energies below the geomagnetic cutoff have been measured by the AMS experiment at altitudes of 350–390 km, in the latitude interval ±51.7°. The ...production mechanisms of the observed trapped fluxes are investigated in detail by means of the FLUKA Monte Carlo simulation code. All known processes involved in the interaction of the cosmic rays with the atmosphere (detailed descriptions of the magnetic field and the atmospheric density, as well as the electromagnetic and nuclear interaction processes) are included in the simulation. The results are presented and compared with experimental data, indicating good agreement with the observed fluxes. The impact of the secondary proton flux on particle production in atmosphere is briefly discussed.
The Alpha Magnetic Spectrometer is designed for a long duration measurement of the cosmic-ray spectra at an altitude of 400
km. The particle rigidity and specific energy loss are measured by a ...silicon tracker located in a 0.8
T field. Ground results for the position resolution, detection efficiency and charge determination for singly and doubly charged relativistic particles are presented and discussed in the context of the spaceborne detector.
The properties of carbon nanotubes (CNTs), the new allotropic status of carbon discovered in 1991, have been widely investigated in all possible application field. This new material in fact can be ...easily obtained chemically by CVD (Chemical Vapour Deposition) as a layer of nanotubes growth on a wide variety of materials. When growth on a silicon surface, CNTs create a semiconductor heterojunction with peculiar photoresponsivity properties. We studied this heterojunction with the purpose to realize a large photocathode with high quantum efficiency in a large wavelength range from UV to IR. Results obtained up to day allowed us to build a new kind of photodetector very cheap, stable and easy to manage. Recently this new device has been proposed as one of candidates for the beam monitor system of SuperB.
The Alpha Magnetic Spectrometer (AMS01), a high-sensitivity particle spectrometer, was successfully flown for 10 d in June 1998 (STS91) in the orbit of the International Space Station (51.7°, ∼380 ...km). A high-statistics dataset of galactic cosmic rays were measured as a function of geomagnetic latitude, including the primary protons, leptons and helium as well as the trapped and quasi-trapped proton and lepton components. In this paper, the absorbed dose rate owing to the protons, leptons and helium are presented and compared with measurements made by other instruments flown on the same mission.
The primary proton spectrum in the kinetic energy range 0.2 to 200 GeV was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS–91 at an altitude of 380 km. The complete ...data set combining three shuttle attitudes and including all known systematic effects is presented.
Progress in the realization of a silicon-CNT photodetector Aramo, C.; Ambrosio, A.; Ambrosio, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2012, Letnik:
695
Journal Article
Recenzirano
The realization of a Silicon Carbon Nanotube heterojuntion opens the door to a new generation of photodetectors (Si-CNT detector) based on the coupling between this two materials. In particular the ...growth of Multiwall Carbon Nanotubes on the surface of a n-doped silicon substrate results on a Schottky diode junction with precise rectifying characteristics. The obtained device presents a low dark current, high efficiency in the photoresponsivity, high linearity and a wide stability range. The junction barrier is about 3.5V in reverse polarity with a breakdown limit at more than 100V. The spectral behavior reflects the silicon spectral range with a maximum at about 880nm.
Leptons in near earth orbit Ambrosi, G.; Ao, L.; Arefiev, A. ...
Physics letters. B,
06/2000, Letnik:
484, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The lepton spectra in the kinetic energy ranges 0.2 to 40 GeV for e
− and 0.2 to 3 GeV for e
+ were measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS–91 at altitudes ...near 380
km. From the origin of the leptons two distinct spectra were observed: a higher energy spectrum and a substantial second spectrum with positrons much more abundant than electrons. Tracing leptons from the second spectra shows that most of these leptons travel for an extended period of time in the geomagnetic field and that the e
+ and e
− originate from two complementary geographic regions.
The third generation of Near Ultraviolet High Density (NUV-HD3) Silicon Photomultipliers (SiPMs) produced by Fondazione Bruno Kessler in collaboration with Istituto Nazionale di Fisica Nucleare ...(INFN) have been tested and characterized in INFN laboratories. Arrays of 16 pixels have been assembled to equip the focal plane of the prototype Schwarzschild-Couder Medium Size Telescope (pSCT) proposed for the Cherenkov Telescope Array Observatory. Each camera module is composed by 4 matrices of 16-pixel optical units coupled with TARGET-7 ASIC front-end electronics for signal amplification and digitization. A total of 9 modules have been successfully integrated on the pSCT camera and are currently taking data. In this contribution we provide a summary of the performances of the HD3 technology as measured in the INFN laboratories. We also report on the laboratory tests performed on the assembled optical units, showing their performances and homogeneity in terms of gain, signal-to-noise ratio and dark count rate.
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