The momentum spectrum and charge ratio of μ-mesons at sea-level-II

Geosci. Instrum. Method. Data Syst.

Ohshiro

2016

Abstract. Muographic measurements of rock overburdens are of particular interest because they can be applied to natural resources and undiscovered cave explorations, and even to searching for hidden chambers in historic architectural structures. In order to derive the absolute density distribution of the overburden, we conventionally needed to know accurate information about the measurement conditions, e.g., the detector's geometrical acceptance, detection efficiency, and measurement time, in order to derive the absolute value of the transmitted muon flux. However, in many cases, it is not a simple task to accurately gauge such conditions. Open-sky muon data taken with the same detector are useful as reference data to cancel these factors; however, if the detector is not transportable, this data taking method is not feasible. In this work, we found that the transmitted muon flux will follow a simple function of the areal density along the muon path as long as the incident muon energies are below a few hundred GeV. Based on this finding, we proposed a simple analysis method that does not require detailed knowledge of the detector's conditions by combining the independently measured density information for the partial volume of the target. We anticipate that this simple method is applicable to future muographic measurements of rock overburdens.

Section: Cosmic-ray Muonsmentioning

confidence: 99%

Muographic data analysis method for medium-sized rock overburden inspections

Geosci. Instrum. Method. Data Syst.

Ohshiro

2016

“…A significant amount of data related to the energy spectrum of muons has been accumulated over the past 50 years 16 – 18 ) and the spectrum has been modeled. 19 – 22 )…”

Section: Principles Of Muographymentioning

confidence: 99%

Muographic imaging with a multi-layered telescope and its application to the study of the subsurface structure of a volcano

Kusagaya

Proceedings of the Japan Academy. Ser. B: Physical and Biologic

2015

In conventional muography observations using two detectors for muon tracking, the accidental coincidence of vertical electromagnetic showers generates identical trajectories to the muon tracks. Although muography has favorable properties, which allow direct density measurements inside a volcano, the measured density is lower than the actual value due to these fortuitous trajectories. We performed muography of Usu volcano, and confirmed that, in comparison with a use of two detectors, background noise levels were reduced by more than one order of magnitude using seven detectors for selecting linear trajectories. The resultant muographic image showed a high-density region underneath the central region of Usu volcano. This picture is consistent with the magma intrusion model proposed in previous studies. To clarify the three-dimensional location and actual size of the detected high-density body, multidirectional muographic measurements are necessary.

“…Primary cosmic rays reacting with the nitrogen and oxygen nuclei at the top of Earth's atmosphere produce mostly pions, which subsequently decay via the process represented as π (pion) → μ (muon) + ν (neutrino). Because of this simple two-body reaction chain, the zenith-angle energy spectrum of muons can be accurately predicted (Bull et al 1965, Matsuno et al 1984, Bugaev et al 1998, Gaisser & Stanev 2008. In the vicinity of Earth, primary cosmic rays arrive isotropically, and the initial information about the course they took to arrive from the source (e.g., a supernova) is completely lost, hence the azimuthal distribution of resultant muons.…”

Section: Principlementioning

confidence: 99%

Particle Geophysics

Annu. Rev. Earth Planet. Sci.

2014

Geophysics research has long been dominated by classical mechanics, largely disregarding the potential of particle physics to augment existing techniques. The purpose of this article is to review recent progress in probing Earth's interior with muons and neutrinos. Existing results for various volcanological targets are reviewed. Geoneutrinos are also highlighted as examples in which the neutrino probes elucidate the composition of Earth's deep interior. Particle geophysics has the potential to serve as a useful paradigm to transform our understanding of Earth as dramatically as the X-ray transformed our understanding of medicine and the body.