Determination of self shielding factors and gamma attenuation effects for tree ring samples

Daǧistan Şahin, Kenan Ünlü

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Determination of tree ring chemistry using Neutron Activation Analysis (NAA) is part of an ongoing research between Penn State University (PSU) and Cornell University, The Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology. Tree-ring chemistry yields valuable data for environmental event signatures. These signatures are a complex function of elemental concentration. To be certain about concentration of signature elements, it is necessary to perform the measurements and corrections with the lowest error and maximum accuracy possible. Accurate and precise values of energy dependent neutron flux at dry irradiation tubes and detector efficiency for tree ring sample are calculated for Penn State Breazeale Reactor (PSBR). For the calculation of energy dependent and self shielding corrected neutron flux, detailed model of the TRIGA Mark III reactor at PSU with updated fuel compositions was prepared using the MCNP utility for reactor evolution (MURE) libraries. Dry irradiation tube, sample holder and sample were also included in the model. The thermal flux self-shielding correction factors due to the sample holder and sample for were calculated and verified with previously published values. The Geant-4 model of the gamma spectroscopy system, developed at Radiation Science and Engineering Center (RSEC), was improved and absolute detector efficiency for tree-ring samples was calculated.

Original languageEnglish (US)
Pages (from-to)549-553
Number of pages5
JournalJournal of Radioanalytical and Nuclear Chemistry
Issue number2
StatePublished - May 2012

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry
  • Nuclear Energy and Engineering
  • Radiology Nuclear Medicine and imaging
  • Pollution
  • Spectroscopy
  • Public Health, Environmental and Occupational Health
  • Health, Toxicology and Mutagenesis


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