Highly penetrating cosmic ray muons constantly shower the earth at a rate of about 1 muon per cm2 per minute. We have developed a technique which exploits the multiple Coulomb scattering of these particles to perform nondestructive inspection without the use of artificial radiation. In prior work [1]-[3], we have described heuristic methods for processing muon data to create reconstructed images. In this paper, we present a maximum likelihood/expectation maximization tomographic reconstruction algorithm designed for the technique. This algorithm borrows much from techniques used in medical imaging, particularly emission tomography, but the statistics of muon scattering dictates differences. We describe the statistical model for multiple scattering, derive the reconstruction algorithm, and present simulated examples. We also propose methods to improve the robustness of the algorithm to experimental errors and events departing from the statistical model.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1109/tip.2007.901239 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Nanoscale characterization of space weathering in lunar samples.
Sci Rep
January 2025
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Nanoscale Fourier transform infrared (Nano-FTIR) imaging and spectroscopy correlated with photoluminescence measurements of lunar Apollo samples with different surface radiation exposure histories reveal distinct physical and chemical differences associated with space weathering effects. Analysis of two sample fragments: an ilmenite basalt (12016) and an impact melt breccia (15445) show evidence of intrinsic or delivered Nd and an amorphous silica glass component on exterior surfaces, whereas intrinsic Cr and/or trapped electron states are limited to interior surfaces. Spatially localized 1050 cm/935 cm band ratios in Nano-FTIR hyperspectral maps may further reflect impact-induced shock nanostructures, while shifts in silicate band positions indicate accumulated radiation damage at the nanoscale from prolonged space weathering due to micrometeorites, solar wind, energetic x-rays and cosmic ray bombardment.
View Article and Find Full Text PDFInfrared spectroscopy of α-pinene ices irradiated by energetic ions at temperatures relevant to astronomical environments.
Spectrochim Acta A Mol Biomol Spectrosc
December 2024
Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marquês de São Vicente 225, Rio de Janeiro 22451-900, RJ, Brazil.
The effects of cosmic-ray bombardment of chiral molecules in the interstellar medium are simulated in the laboratory by performing radiolysis experiments of pure α-pinene ices at four different temperatures. The identification and significance of α-pinene have not been fully understood because of the insufficient amount of spectral information of these compounds at low temperatures. A comparison of the temperature dependence of the mid-infrared spectra of pure α-pinene ices before and after irradiation its irradiation by 61.
View Article and Find Full Text PDFHigh-Statistics Measurement of the Cosmic-Ray Electron Spectrum with H.E.S.S.
Phys Rev Lett
November 2024
Centre for Space Research, North-West University, Potchefstroom 2520, South Africa.
Owing to their rapid cooling rate and hence loss-limited propagation distance, cosmic-ray electrons and positrons (CRe) at very high energies probe local cosmic-ray accelerators and provide constraints on exotic production mechanisms such as annihilation of dark matter particles. We present a high-statistics measurement of the spectrum of CRe candidate events from 0.3 to 40 TeV with the High Energy Stereoscopic System, covering 2 orders of magnitude in energy and reaching a proton rejection power of better than 10^{4}.
View Article and Find Full Text PDFSearching for Asymmetric and Heavily Precessing Binary Black Holes in the Gravitational Wave Data from the LIGO Third Observing Run.
Phys Rev Lett
November 2024
Department of Physics, Hayes Hall, Kenyon College, Gambier, Ohio 43022, USA.
Leveraging the features of the GstLAL pipeline, we present the results of a matched filtering search for asymmetric binary black hole systems with heavily misaligned spins in LIGO and Virgo data taken during the third observing run. Our target systems show strong imprints of precession whereas current searches have nonoptimal sensitivity in detecting them. After measuring the sensitivity improvement brought by our search over standard spin-aligned searches, we report the detection of 30 gravitational wave events already discovered in the latest version of the Gravitational Wave Transient Catalog.
View Article and Find Full Text PDFFirst Indication of Solar ^{8}B Neutrinos via Coherent Elastic Neutrino-Nucleus Scattering with XENONnT.
Phys Rev Lett
November 2024
Department of Physics, University of California San Diego, La Jolla, California 92093, USA.
Article Synopsis
- The XENONnT dark matter experiment successfully measured nuclear recoils from solar ^{8}B neutrinos, marking a significant advancement in neutrino detection technology.
- Using a two-phase time projection chamber with a 5.9 t liquid xenon target, the experiment produced 37 observed events, which surpassed the expected background events, indicating a notable signal.
- The results provide a measured solar neutrino flux consistent with previous studies and confirm the neutrino cross section predictions aligned with the Standard Model, showcasing the effectiveness of dark matter detectors in neutrino research.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!