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Title: Effect of atmospheric conditions on operation of terahertz systems for remote detection of ionizing materials

This study was motivated by a new concept of remote detection of concealed radioactive materials by using a high power terahertz (THz) wave beam, which can be focused in a small spot where the wave electric field exceeds the breakdown threshold. In the presence of seed electrons in such a volume, this focusing can initiate the avalanche breakdown. Typically, an ambient density of free electrons is assumed to be at the level of one particle per cubic centimeter. So, when a breakdown-prone volume is smaller than 1 cm{sup 3}, there should be significant difference between the breakdown rates in the case of presence of additional sources of ionization versus its absence. Since the flux density of gamma rays emitted by radioactive materials rapidly falls with the distance from the source, while the intensity of THz waves also decreases with the distance due to wave attenuation in the atmosphere, it is important to find an optimal location of the breakdown to be initiated for a given distance between a radioactive material and a THz antenna. This problem is analyzed in a given paper with the account for not only atmospheric attenuation of THz waves but also the air turbulence.
Authors:
;  [1] ; ;  [2]
  1. IREAP, University of Maryland, College Park, Maryland 20742-3511 (United States)
  2. FIR Center, University of Fukui, Fukui 910-8507 (Japan)
Publication Date:
OSTI Identifier:
22252137
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 1; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AIR; ANTENNAS; ATTENUATION; BREAKDOWN; DETECTION; DISTANCE; ELECTRIC FIELDS; ELECTRONS; FLUX DENSITY; GAMMA RADIATION; OPERATION; RADIOACTIVE MATERIALS