Advanced

Search for lost Point Sources using Mobile Gamma Spectrometry

Hjerpe, Thomas (1997)
Medical Physics Programme
Abstract (Swedish)
En situation som den svenska beredskapen mot kärnenergiolyckor ska klara av är att effektivt och snabbt söka upp eventuella försvunna radioaktiva strålkällor. Nyligen så har Statens strålskyddsinstitut köpt in ett antal mobila detektorsystem som innehåller GPS (ett system för satellitpositionering). Ett av dessa system användes monterat i bil för att undersöka hur långt bort från en väg ett starkt radioaktivt 137Cs preparat kunde placeras och fortfarande upptäckas. Inverkan på resultatet av olika sätt att placera detektorn i bilen undersöktes också.
Abstract (Swedish)
"At searching for lost point sources, it is important to use an optimal search strategy and an optimal methodology for spectrum data analysis.

The purpose of this work is to evaluate a simple on-line method for locating lost point sources in the environment with carborne gamma spectrometry and study different strategies for detector geometries and speed of the car.

The scope of this thesis has been limited to investigate how far away from a road a strong radioactive source can be located and still be detected. Suggestions for further investigations will also be presented.

A 6 GBq 137Cs point source placed at various distances from the car-borne NaI-detector/MCA/computer system was used for evaluation. The evaluated method... (More)
"At searching for lost point sources, it is important to use an optimal search strategy and an optimal methodology for spectrum data analysis.

The purpose of this work is to evaluate a simple on-line method for locating lost point sources in the environment with carborne gamma spectrometry and study different strategies for detector geometries and speed of the car.

The scope of this thesis has been limited to investigate how far away from a road a strong radioactive source can be located and still be detected. Suggestions for further investigations will also be presented.

A 6 GBq 137Cs point source placed at various distances from the car-borne NaI-detector/MCA/computer system was used for evaluation. The evaluated method compares the full energy peak countrate in the 137Cs window in a few consecutive spectra and the corresponding countrates in the closest adjacent spectral distributions. A t-test is used to determine if there is significantly less peak area in the adjacent spectra. Two different geometries were investigated, the detector facing backwards and the detector facing sidewards.
" (Less)
Please use this url to cite or link to this publication:
author
Hjerpe, Thomas
supervisor
organization
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Radioekologi
language
English
id
2156920
date added to LUP
2011-09-14 12:23:38
date last changed
2013-09-05 10:22:45
@misc{2156920,
  abstract     = {"At searching for lost point sources, it is important to use an optimal search strategy and an optimal methodology for spectrum data analysis. 

The purpose of this work is to evaluate a simple on-line method for locating lost point sources in the environment with carborne gamma spectrometry and study different strategies for detector geometries and speed of the car.

The scope of this thesis has been limited to investigate how far away from a road a strong radioactive source can be located and still be detected. Suggestions for further investigations will also be presented. 

A 6 GBq 137Cs point source placed at various distances from the car-borne NaI-detector/MCA/computer system was used for evaluation. The evaluated method compares the full energy peak countrate in the 137Cs window in a few consecutive spectra and the corresponding countrates in the closest adjacent spectral distributions. A t-test is used to determine if there is significantly less peak area in the adjacent spectra. Two different geometries were investigated, the detector facing backwards and the detector facing sidewards. 
"},
  author       = {Hjerpe, Thomas},
  keyword      = {Radioekologi},
  language     = {eng},
  note         = {Student Paper},
  title        = {Search for lost Point Sources using Mobile Gamma Spectrometry},
  year         = {1997},
}