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Title: Using Muons to Image the Subsurface.

Muons are subatomic particles that can penetrate the earth 's crust several kilometers and may be useful for subsurface characterization . The absorption rate of muons depends on the density of the mat erials through which they pass. Muons are more sensitive to density variation than other phe nomena, including gravity , making them beneficial for subsurface investigation . Measurements of muon flux rate at differing directions provide density variations of the materials between the muon source (cosmic rays and neutrino interactions) and the detec tor, much like a CAT scan. Currently, muon tomography can resolve features to the sub - meter scale. This work consists of three parts to address the use of muons for subsurface characterization : 1) assess the use of muon scattering for estimating density d ifferences of common rock types, 2 ) using muon flux to detect a void in rock , 3) measure muon direction by designing a new detector. Results from this project lay the groundwork for future directions in this field. L ow - density objects can be detected by mu ons even when enclosed in high - density material like lead and even small changes in density (e.g. changes due tomore » fracturing of material) can be detected. R ock density has a linear relationship with muon scattering density per rock volume when this ratio is greater than 0.10 . Limitations on using muon scattering to assess density changes among common rock types have been identified. However, other analysis methods may show improved results for these relatively low density materials. S imulations show that muo ns can be used to image void space (e.g. tunnels) within rock but experimental results have been ambiguous . I mprovements are suggested to improve imaging voids such as tunnels through rocks. Finally, a muon detector has been designed and tested to measure muon direction, which will improve signal to noise ratio and help address fu ndamental questions about the source of upgoing muons .« less
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [2]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  2. NSTec, Livermore, CA (United States)
Publication Date:
OSTI Identifier:
1333270
Report Number(s):
SAND--2016-11650
649178
DOE Contract Number:
AC04-94AL85000
Resource Type:
Technical Report
Research Org:
Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS