18 research outputs found
Cosmic-ray positron fraction measurement from 1 to 30 GeV with AMS-01
No full textA measurement of the cosmic ray positron fraction e+/(e+ + e-) in the energy range of 1-30 GeV is presented. The measurement is based on data taken by the AMS-01 experiment during its 10 day Space Shuttle flight in June 1998. A proton background suppression on the order of 10^6 is reached by identifying converted bremsstrahlung photons emitted from positrons.A measurement of the cosmic ray positron fraction e+/(e++e−) in the energy range of 1–30 GeV is presented. The measurement is based on data taken by the AMS-01 experiment during its 10 day Space Shuttle flight in June 1998. A proton background suppression on the order of 10 6 is reached by identifying converted bremsstrahlung photons emitted from positrons.A measurement of the cosmic ray positron fraction e+/(e+ + e-) in the energy range of 1-30 GeV is presented. The measurement is based on data taken by the AMS-01 experiment during its 10 day Space Shuttle flight in June 1998. A proton background suppression on the order of 10^6 is reached by identifying converted bremsstrahlung photons emitted from positrons
Leptons in near earth orbit
No full textThe 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
Hadron calorimetry in the L3 detector
Get PDFThe characteristics of the L3 hadron calorimeter as realized in the observation of hadronic jets and other events from e+e- collisions at LEP are presented and discussed. The pattern-recognition algorithm utilizing the fine granulatiry of the calorimeter is described, and the observed overall resolution of 10.2% for hadron jets from Z decay is reported. The use of the calorimeter in providing information on muon energy losses is also noted.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29386/1/0000457.pd
Leptons in near earth orbit
No full textThe 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. (Elsevier
ISOTOPIC COMPOSITION OF LIGHT NUCLEI IN COSMIC RAYS: RESULTS FROM AMS-01
No full textThe variety of isotopes in cosmic rays allows us to study different aspects of the processes that cosmic rays undergo between the time they are produced and the time of their arrival in the heliosphere. In this paper, we present measurements of the isotopic ratios (2)H/(4)He, (3)He/(4)He, (6)Li/(7)Li, (7)Be/((9)Be+(10)Be), and (10)B/(11)B in the range 0.2-1.4 GeV of kinetic energy per nucleon. The measurements are based on the data collected by the Alpha Magnetic Spectrometer, AMS-01, during the STS-91 flight in 1998 June
A Study of Cosmic Ray Secondaries Induced by the Mir Space Station Using AMS-01
Get PDFThe Alpha Magnetic Spectrometer (AMS-02) is a high energy particle physics experiment that will study cosmic rays in the to range and will be installed on the International Space Station (ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew aboard the space shuttle \emph{Discovery} from June 2 to June 12, 1998, and collected cosmic ray triggers. Part of the \emph{Mir} space station was within the AMS-01 field of view during the four day \emph{Mir} docking phase of this flight. We have reconstructed an image of this part of the \emph{Mir} space station using secondary and emissions from primary cosmic rays interacting with \emph{Mir}. This is the first time this reconstruction was performed in AMS-01, and it is important for understanding potential backgrounds during the 3 year AMS-02 mission
The Alpha Magnetic Spectrometer (AMS) on the international space station: Part I - results from the test flight on the space shuttle
No full textThe Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle Discovery during flight STS-91 (June 1998) in a 51.7° orbit at altitudes between 320 and.A search for antihelium nuclei in the rigidity range 1–was performed. No antihelium nuclei were detected at any rigidity. An upper limit on the flux ratio of antihelium to helium of <1.1×10−6 was obtained.The high energy proton, electron, positron, helium, antiproton and deuterium spectra were accurately measured.For each particle and nuclei two distinct spectra were observed: a higher energy spectrum and a substantial second spectrum. Positrons in the second spectrum were found to be much more abundant than electrons. Tracing particles from the second spectra shows that most of them travel for an extended period of time in the geomagnetic field, and that the positive particles (p and e+) and negative ones (e−) originate from two complementary geographic regions. The second helium spectrum flux over the energy range 0.1–was measured to be . Over 90 percent of the helium flux was determined to be at the 90% confidence level. (Elsevier
Relative Composition and Energy Spectra of Light Nuclei in Cosmic Rays: Results from AMS-01
Get PDFMeasurement of the chemical and isotopic composition of cosmic rays is essential for the precise understanding of their propagation in the galaxy. While the model parameters are mainly determined using the B/C ratio, the study of extended sets of ratios can provide stronger constraints on the propagation models. In this paper, the relative abundances of light-nuclei lithium, beryllium, boron, and carbon are presented. The secondary-to-primary ratios Li/C, Be/C, and B/C have been measured in the kinetic energy range 0.35-45 GeV nucleon[superscript –1]. The isotopic ratio [superscript 7]Li/[superscript 6]Li is also determined in the magnetic rigidity interval 2.5-6.3 GV. The secondary-to-secondary ratios Li/Be, Li/B, and Be/B are also reported. These measurements are based on the data collected by the Alpha Magnetic Spectrometer AMS-01 during the STS-91 space shuttle flight in 1998 June. Our experimental results are in substantial agreement with other measurements, where they exist. We describe our light-nuclei data with a diffusive-reacceleration model. A 10%-15% overproduction of Be is found in the model predictions and can be attributed to uncertainties in the production cross-section data
