The propagation of cosmic rays inside our galaxy plays a fundamental role in shaping their injection spectra into those observed at Earth. One of the best tools to investigate this issue is the ratio ...of fluxes for secondary and primary species. The boron-to-carbon (B/C) ratio, in particular, is a sensitive probe to investigate propagation mechanisms. This paper presents new measurements of the absolute fluxes of boron and carbon nuclei as well as the B/C ratio from the PAMELA space experiment. The results span the range 0.44-129 GeV/n in kinetic energy for data taken in the period 2006 July to 2008 March.
The upgraded beam monitor system of the FAMU experiment at RIKEN–RAL Bonesini, M.; Benocci, R.; Bertoni, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2019, Volume:
936
Journal Article
Peer reviewed
Open access
A set of three X/Y beam hodoscopes based on square Bicron BCF12 scintillating fibers read by SiPM has been developed for the FAMU experiment at RIKEN–RAL. A beam width (RMS) less than 10 mm is ...measured in both X/Y directions. Muon rates are measured and found compatible with previous data.
•Monitoring of high intensity low-energy pulsed muon beam.•System of three beam hodoscopes based on Bicron BCF12 scintillating fibers and SiPM readout.•Multiple information on beam profile, beam intensity and timing from FADC readout.
ABSTRACT Precision measurements of the electron component of cosmic radiation provide important information about the origin and propagation of cosmic rays in the Galaxy not accessible from the study ...of cosmic-ray nuclear components due to their differing diffusion and energy-loss processes. However, when measured near Earth, the effects of propagation and modulation of Galactic cosmic rays in the heliosphere, particularly significant for energies up to at least 30 GeV, must be properly taken into account. In this paper the electron (e−) spectra measured by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics down to 70 MeV from 2006 July to 2009 December over six-month time intervals are presented. Fluxes are compared with a state-of-the-art three-dimensional model of solar modulation that reproduces the observations remarkably well.
•Muon transfer rate from muonic hydrogen to oxygen measured at RIKEN RAL (UK).•Rise with the temperature of the muon transfer rate from muonic hydrogen to oxygen.•Use of LaBr3 fast scintillator ...counters read by photomultiplier.•Important basis to measure the hyperfine splitting of muonic hydrogen.
The first measurement of the temperature dependence of the muon transfer rate from muonic hydrogen to oxygen was performed by the FAMU collaboration in 2016. The results provide evidence that the transfer rate rises with the temperature in the range 104-300 K. This paper presents the results of the experiment done in 2018 to extend the measurements towards lower (70 K) and higher (336 K) temperatures. The 2018 results confirm the temperature dependence of ΛpO observed in 2016 and sets firm ground for comparison with the theoretical predictions.
Scintillating crystals coupled to SiPM array readout have been proposed to realize compact X-rays detectors for the FAMU experiment, which aims to accurately measure the hyperfine splitting of the ...ground state of the muonic hydrogen atom. A measurement of the transfer rate of muons from hydrogen to heavier gases is necessary for this purpose. Since 2014, in a series of test runs, a pressurized gas-target was exposed to the pulsed low-energy muon beam at the RIKEN RAL muon facility (Rutherford Appleton Laboratory, U.K.). The main goal of these tests was the characterization of both the background induced by the pulsed beam and the X-ray detectors. Preliminary results are shown on the use of new Pr:LuAG and Ce:GAGG crystals, developed for PET scanners and of more conventional LaBr3:Ce crystals, with a SiPM array readout. Energy spectra of the X-rays produced after the de-excitation of muonic atoms formed from the interaction of the beam muons with the gas target in the FAMU apparatus are shown, demonstrating the suitability of these detectors for muonic X-rays spectroscopy.
ABSTRACT The cosmic-ray hydrogen and helium (1H, 2H, 3He, 4He) isotopic composition has been measured with the satellite-borne experiment PAMELA, which was launched into low-Earth orbit on board the ...Resurs-DK1 satellite on 2006 June 15. The rare isotopes 2H and 3He in cosmic rays are believed to originate mainly from the interaction of high-energy protons and helium with the galactic interstellar medium. The isotopic composition was measured between 100 and 1100 MeV/n for hydrogen and between 100 and 1400 MeV/n for helium isotopes using two different detector systems over the 23rd solar minimum from 2006 July to 2007 December.
We report the first measurement of the deuterium abundance in cosmic rays above 10 GeV nucleon super(-1) of kinetic energy. The data were collected by the balloon-borne experiment CAPRICE98, which ...was flown on 1998 May 28-29 from Fort Sumner, New Mexico. The detector configuration included the NMSU-WiZard/CAPRICE superconducting magnet spectrometer equipped with a gas RICH detector, a silicon-tungsten calorimeter, and a time-of-flight system. By combining the information from the spectrometer and the RICH detector, it was possible to separate deuterons from protons in the kinetic energy range from 12 to 22 GeV nucleon super(-1). In order to estimate the proton background and the deuteron selection efficiency, we developed an empirical model for the response of the instrument, based on the data collected in this experiment. The analysis procedure is described in this paper, and the result on the absolute flux of deuterium is presented. We found that the deuterium abundance at high energy is consistent with the hypothesis that the propagation mechanism of light nuclei is the same as that of heavier secondary components.
The PAMELA experiment is a satellite-borne apparatus designed to study charged particles in the cosmic radiation with a particular focus on antiparticles. PAMELA is mounted on the Resurs DK1 ...satellite that was launched from the Baikonur cosmodrome on June 15th 2006. The PAMELA apparatus comprises a time-of-flight system, a magnetic spectrometer, a silicon–tungsten electromagnetic calorimeter, an anticoincidence system, a shower tail catcher scintillator and a neutron detector. The combination of these devices allows antiparticles to be reliably identified from a large background of other charged particles. This paper reviews the design, space qualification and on-ground performance of PAMELA. The in-orbit performance will be discussed in future publications.
•Temperature dependence of the μ transfer rate from μp to oxygen is measured.•A strong monotonic rise by a factor three of the rate is observed between 104-300 K.•This effect will be exploited to ...measure the hyperfine splitting of the μp 1S state.•Experiment took place at the RIKEN muon facility, Rutherford Appleton Laboratory.•Fast scintillator counters based on LaBr3 crystals read by photomultipliers are used.
We report the first measurement of the temperature dependence of muon transfer rate from muonic hydrogen atoms to oxygen between 100 and 300 K. Data were obtained from the X-ray spectra of delayed events in a gaseous target, made of a H2/O2 mixture, exposed to a muon beam. This work sets constraints on theoretical models of muon transfer and is of fundamental importance for the measurement of the hyperfine splitting of muonic hydrogen ground state as proposed by the FAMU collaboration.
It is interesting to measure the antiproton galactic component in cosmic rays in order to study the mechanisms by which particles and antiparticles are generated and propagate in the Galaxy and to ...search for new sources of, e.g., annihilation or decay of dark matter hypothetical particles. The antiproton spectrum and the ratio of the fluxes of primary cosmic ray antiprotons to protons with energies of 60 MeV to 350 GeV found from the data obtained from June 2006 to January 2010 in the PAMELA experiment are presented. The usage of the advanced data processing method based on the data classification mathematical model made it possible to increase statistics and analyze the region of higher energies than in the earlier works.
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