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Accounting for the depth distribution of (137)Cs in on-line mobile gamma spectrometry through primary and forward-scattered photons.

Hjerpe, Thomas LU and Samuelsson, Christer LU (2002) In Radiation and Environmental Biophysics 41(3). p.225-230
Abstract
Stationary and mobile field gamma spectrometry is a useful tool for rapid estimation of environmental radioactivity inventories on and in the ground. A weak point however, is that the depth distribution of the activity in the ground must be known in order to calculate the true activity per unit area or unit mass from an observed photon fluence rate. A promising method for converting incoming spectral data into both true activity content and depth distribution in real time is the peak-to-valley method, which is based on an analysis of the ratio between count rates from primary and forward-scattered photons. In this study the peak-to-valley method was adapted to car-borne mobile gamma spectrometry, where the depth distribution of (137)Cs is... (More)
Stationary and mobile field gamma spectrometry is a useful tool for rapid estimation of environmental radioactivity inventories on and in the ground. A weak point however, is that the depth distribution of the activity in the ground must be known in order to calculate the true activity per unit area or unit mass from an observed photon fluence rate. A promising method for converting incoming spectral data into both true activity content and depth distribution in real time is the peak-to-valley method, which is based on an analysis of the ratio between count rates from primary and forward-scattered photons. In this study the peak-to-valley method was adapted to car-borne mobile gamma spectrometry, where the depth distribution of (137)Cs is fitted to a Lorenz function. Results from field experiments with a large HPGe detector, utilising point sources at different depths, are presented. It was found that the method can be useful for mobile measurements with a measuring time of 5-10 min for activity concentrations of about 100 kBq.m(-2) or higher, resulting in an uncertainty in the estimate of the true activity of about 50%. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Radiation and Environmental Biophysics
volume
41
issue
3
pages
225 - 230
publisher
Springer
external identifiers
  • pmid:12373332
  • wos:000179024800009
ISSN
1432-2099
DOI
10.1007/s00411-002-0158-3
language
English
LU publication?
yes
id
b4fdb47e-f42d-4c7f-b4df-0c1601f3ff30 (old id 110703)
alternative location
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12373332&dopt=Abstract
date added to LUP
2007-07-19 16:19:06
date last changed
2016-04-16 04:08:19
@article{b4fdb47e-f42d-4c7f-b4df-0c1601f3ff30,
  abstract     = {Stationary and mobile field gamma spectrometry is a useful tool for rapid estimation of environmental radioactivity inventories on and in the ground. A weak point however, is that the depth distribution of the activity in the ground must be known in order to calculate the true activity per unit area or unit mass from an observed photon fluence rate. A promising method for converting incoming spectral data into both true activity content and depth distribution in real time is the peak-to-valley method, which is based on an analysis of the ratio between count rates from primary and forward-scattered photons. In this study the peak-to-valley method was adapted to car-borne mobile gamma spectrometry, where the depth distribution of (137)Cs is fitted to a Lorenz function. Results from field experiments with a large HPGe detector, utilising point sources at different depths, are presented. It was found that the method can be useful for mobile measurements with a measuring time of 5-10 min for activity concentrations of about 100 kBq.m(-2) or higher, resulting in an uncertainty in the estimate of the true activity of about 50%.},
  author       = {Hjerpe, Thomas and Samuelsson, Christer},
  issn         = {1432-2099},
  language     = {eng},
  number       = {3},
  pages        = {225--230},
  publisher    = {Springer},
  series       = {Radiation and Environmental Biophysics},
  title        = {Accounting for the depth distribution of (137)Cs in on-line mobile gamma spectrometry through primary and forward-scattered photons.},
  url          = {http://dx.doi.org/10.1007/s00411-002-0158-3},
  volume       = {41},
  year         = {2002},
}