- Restrictions on Access:
- Open Access.
- Cosmic rays are charged nuclei or particles that travel through space and originate from many astrophysical sources. The study of cosmic ray energetics and galactic propagation has been an active field of study within particle astrophysics especially within the past couple of decades. Although these studies have examined the cosmic ray flux at various energy levels, no study has examined the isotopic abundance ratio of cosmic rays at relativistic energies. The High Energy Light Isotope eXperiment (HELIX) is an ongoing NASA sponsored project aimed at launching a high-altitude balloon detector payload above the Antarctic atmosphere in order to detect cosmic rays before they interact with atmospheric particles. The main goal of HELIX is to measure the abundance ratio of the unstable (_ ^10)Be and the stable (_ ^9)Be clock isotopes. These nuclei are produced as secondary by-products of heavier cosmic rays interacting during their interstellar transport with the dilute gas between the stars of the Milky Way galaxy. Once produced, the half-life of the (_ ^10)Be isotope is known to be approximately 1.39 Myr while (_ ^9)Be isotopes are stable, and so these nuclei serve as an ideal abundance ratio in order to determine the galactic propagation time of cosmic rays before arriving at Earth. Moreover, in the energy range of 1 GeV/n to 10 GeV/n, the relativistic time dilation of these nuclei allow them to survive longer in our reference frame, and thus tracking their abundance ratio as a function of energy samples a progressively larger volume of the galaxy, covering the disk of the galaxy at 1 GeV/n and extending into the galactic halo at 10 GeV/n.The difficulty of isotope nuclei detection and identification requires that the HELIX payload have a high resolution of both particle rigidity and velocity in order to obtain mass resolution within a statistically significant range. In order to obtain the required resolution, the HELIX payload is being constructed with a 1T superconducting magnet, hybrid gas drift tracking chamber, time-of-flight and charge detectors, as well as a ring imaging Cherenkov detector. The design and construction of these components is vital to obtain the rigidity and velocity resolutions required in order to make the desired isotope abundance measurements during HELIXs scheduled first launch in 2020.
- Dissertation Note:
- B.S. Pennsylvania State University 2019.
- Technical Details:
- The full text of the dissertation is available as an Adobe Acrobat .pdf file ; Adobe Acrobat Reader required to view the file.
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