Properties of Cosmic Helium Isotopes Measured by the Alpha Magnetic Spectrometer

Advantages and Requirements in Time Resolving Tracking for Astroparticle Experiments in Space

“…Operating thinner Si-sensors (150 µm instead of 300 µm used in AMS-02 and PAMELA) will reduce the material budget of tracking systems and will consequently improve the momentum resolution for spectrometers at low energies. In the spectrometer detectors recently operated in space, the Coulomb Multiple Scattering (MS) is, indeed, dominating the rigidity resolution up to several tens of GVs [83] (rigidity, R, is defined as momentum p over charge q ratio, p/|q|), while, at higher particle momenta, the finite spatial resolution of the tracking detector increasingly dominates the momentum resolution, leading to the momentum resolution parametrization σ p /p ∝ p. Although many experimental efforts in the technological development of tracking systems for spectrometers were conducted to improve the rigidity resolution at energies above 100 GV to search for new phenomena in this energy range [26,[84][85][86], the momentum range below 10 GV is typically the only region where isotopic distinction is feasible [87] and where the momentum resolution dominates the mass measurement resolution (…”

Beryllium Radioactive Isotopes as a Probe to Measure the Residence Time of Cosmic Rays in the Galaxy and Halo Thickness: A “Data-Driven” Approach

“…This approach requires a very well tuned Monte Carlo simulation of the experiment, and the possible small residual discrepancies with the real detector response could prevent the measurement of the (interesting) small amount of 10 Be.…”

“…In the following a new data-driven approach for the measurement of beryllium isotopic abundances with magnetic spectrometers is described; this can evade part of the systematics related to Monte Carlo simulation. As an example, the application of this approach to PAMELA lithium and beryllium event counts, gathered from Figures 3 and 4 of [9], is shown; and a preliminary, new measurement of 10 Be/ 9 Be in the 0.2-0.85 GeV/n range is provided. Figure 3 of [9] contains the numbers of lithium and beryllium events as functions of β measured by the time of flight (ToF) sub-detector and rigidity measured by the silicon tracker, whereas Figure 4 of [9] contains the numbers of lithium and beryllium events as functions of dE/dx measured by the imaging calorimeter and rigidity measured by the silicon tracker.…”

“…Once T 7 is obtained, the other templates can be straightforwardly obtained by using L 7,9 and L 7,10 , and a χ 2 value for the fixed 7 Be/Be and 9 Be/ 10 Be can be obtained by comparison of the sum of the three weighted templates with D(x). The 7 Be/Be and 9 Be/ 10 Be best fit configuration is retrieved by minimizing the χ 2 value.…”

Cosmic-Ray Database Update: Ultra-High Energy, Ultra-Heavy, and Antinuclei Cosmic-Ray Data (CRDB v4.0)

“…More selection criteria allow to ask for matching sub-exp (partial or full) names, specific dates and energy range, and flux rescaling with energy. In the context of long time series provided by both the AMS-02 [47,48,111] and PAMELA [49] experiments, CRDB v4.0 allows to select only (or discard) data from time series, in order not to overcrowd the display of data. This is illustrated on a 'time-series only' selection in Figure 6, where we show Carrington rotation-averaged PAMELA H data from 2006 to 2010 [112].…”