Download Free Measurements Of The Spectra And Isotopic Composition Of Cosmic Ray Helium And Hydrogen Nuclei From 120 235 Mev Nucleon Book in PDF and EPUB Free Download. You can read online Measurements Of The Spectra And Isotopic Composition Of Cosmic Ray Helium And Hydrogen Nuclei From 120 235 Mev Nucleon and write the review.

The isotopic composition of helium in cosmic ray fluxes provides valuable information about cosmic ray propagation through the Galaxy, which is of particular interest to indirect dark matter searches. Helium-3, mainly a secondary cosmic ray species, is primarily produced by spallation of heavier cosmic rays, such as primary helium-4, with interstellar matter. In six years of data taking, AMS has collected the largest available data set on fluxes of cosmic-ray helium. Events are selected to form a clean sample of galactic helium nuclei, for which velocity and rigidity give a measurement of particle mass that allows the measurement of relative isotope abundances. The resolution of measured mass is described in detail by template functions based on the underlying resolutions of the silicon tracker and ring-imaging Cerenkov detector measurements. This thesis presents a measurement of the cosmic ray helium isotope ratio 3 He/ 4He in the range 0.8-10 GeV/nucleon, as obtained through a template fitting approach on AMS data.
Includes entries for maps and atlases.
Three large stacks of nuclear emulsions were exposed during 1964-1966 on high altitude balloons launched from Fort Churchill, Canada; Texas, U.S.A.; and Hyderabad, India. These stacks have been used to study the energy spectrum of the cosmic ray nuclei of calcium and heavier, the so-called VH-nuclei. These measurements result in integral intensity values for energies greater than 7.1, 1.58 and 1.00 GeV per nucleon, together with differential intensities over the range 225 less than E less than 1000 MeV per nucleon. Differential intensities were also found for lighter nuclei over varying energy ranges. The differential spectrum observed has a maximum value of about 0.0016 nuclei/sq m ster. sec. MeV per nucleon around E approximately equals 350 MeV per nucleon and falls off at both higher and lower energies. These values are based on the observation of a total of some 1600 VH-nuclei. The energy spectrum has been compared with that observed at similar times for the helium nuclei in order to study the influences of ionization energy losses during propagation of these high Z nuclei. These observations are interpreted as implying that if the source spectra of the VH-nuclei and the helium nuclei are similar then the VH-nuclei have traversed less than 1 g/sq cm of matter while ionization energy loss has been the dominant acceleration term. (Author).