SU‐GG‐T‐240: New Method of An HPGe Detector Precise Efficiency Calibration with Experimental Measurements and Monte Carlo Simulations

Y. Zhai, L. Trache, R. Tribble, Y. Liu, C. Shi, Nikos Papanikolaou, V. Iacob, J. Hardy, G. Tabacaru

Research output: Contribution to journalArticle

Abstract

Purpose: Developing a method of an HPGe detector precise γ efficiency calibration which is very important for accurate radiation detection during cancer radiotherapy practices. Method and Materials: [formula omitted] radioactive nucleus produced and separated with Momentum Achromat Recoil Spectrometer (MARS) at the K500 superconducting cyclotron of Texas A&M University has positron decays followed by γ transitions up to 8 MeV from [formula omitted] excited states, which is used for a β‐γ coincidence measurement with a 1‐mm‐thick BC404 plastic scintillator, an HPGe detector and a fast tape‐transport system to calibrate the HPGe detector. Results: By carefully considering the effects of summing, positron annihilation, internal conversion, and β detector efficiency when analyzing [formula omitted] spectrum, we got the efficiency for γ‐ray 7070 keV at 49 mm distance away from the source sample [formula omitted], which was 0.192(6)%. The Monte Carlo (MC) simulation with CYLTRAN code gave a value of 0.189%, which was in agreement with our measurements. The precise efficiency calibration curve of the HPGe detector up to 7070 KeV at 49 mm distance away from the source sample was obtained. By using the same procedure, we got the efficiency for the 7070 keV γ‐ray at 151 mm distance away from the source sample [formula omitted], which was 0.0385(8)%. MC simulation value was 0.0399%, which differed from measurement by 4(2)%. This discrepancy led us to assign an uncertainty of 4% to our efficiencies at 151 mm up to 7070 KeV. The Monte Carlo calculations also reproduced the intensity of observed single‐and double‐escape peaks, providing that the effects of positron annihilation‐in‐flight were incorporated. Conclusion: A new method was established. The precise calibration curves obtained from this work are useful for accurate radiation detection and improving quality control to quality assurance (QA) for intensity‐modulated radiation therapy (IMRT). Research sponsored by Department of Energy and Robert Welch Foundation.

Original languageEnglish (US)
Pages (from-to)2780
Number of pages1
JournalMedical Physics
Volume35
Issue number6
DOIs
StatePublished - 2008

Fingerprint

Calibration
Electrons
Radiotherapy
Radiation
Cyclotrons
Quality Control
Plastics
Uncertainty
Research
Neoplasms

ASJC Scopus subject areas

  • Biophysics
  • Radiology Nuclear Medicine and imaging

Cite this

SU‐GG‐T‐240 : New Method of An HPGe Detector Precise Efficiency Calibration with Experimental Measurements and Monte Carlo Simulations. / Zhai, Y.; Trache, L.; Tribble, R.; Liu, Y.; Shi, C.; Papanikolaou, Nikos; Iacob, V.; Hardy, J.; Tabacaru, G.

In: Medical Physics, Vol. 35, No. 6, 2008, p. 2780.

Research output: Contribution to journalArticle

Zhai, Y. ; Trache, L. ; Tribble, R. ; Liu, Y. ; Shi, C. ; Papanikolaou, Nikos ; Iacob, V. ; Hardy, J. ; Tabacaru, G. / SU‐GG‐T‐240 : New Method of An HPGe Detector Precise Efficiency Calibration with Experimental Measurements and Monte Carlo Simulations. In: Medical Physics. 2008 ; Vol. 35, No. 6. pp. 2780.
@article{fe75b2ff4144473bbde5701dfeca441d,
title = "SU‐GG‐T‐240: New Method of An HPGe Detector Precise Efficiency Calibration with Experimental Measurements and Monte Carlo Simulations",
abstract = "Purpose: Developing a method of an HPGe detector precise γ efficiency calibration which is very important for accurate radiation detection during cancer radiotherapy practices. Method and Materials: [formula omitted] radioactive nucleus produced and separated with Momentum Achromat Recoil Spectrometer (MARS) at the K500 superconducting cyclotron of Texas A&M University has positron decays followed by γ transitions up to 8 MeV from [formula omitted] excited states, which is used for a β‐γ coincidence measurement with a 1‐mm‐thick BC404 plastic scintillator, an HPGe detector and a fast tape‐transport system to calibrate the HPGe detector. Results: By carefully considering the effects of summing, positron annihilation, internal conversion, and β detector efficiency when analyzing [formula omitted] spectrum, we got the efficiency for γ‐ray 7070 keV at 49 mm distance away from the source sample [formula omitted], which was 0.192(6){\%}. The Monte Carlo (MC) simulation with CYLTRAN code gave a value of 0.189{\%}, which was in agreement with our measurements. The precise efficiency calibration curve of the HPGe detector up to 7070 KeV at 49 mm distance away from the source sample was obtained. By using the same procedure, we got the efficiency for the 7070 keV γ‐ray at 151 mm distance away from the source sample [formula omitted], which was 0.0385(8){\%}. MC simulation value was 0.0399{\%}, which differed from measurement by 4(2){\%}. This discrepancy led us to assign an uncertainty of 4{\%} to our efficiencies at 151 mm up to 7070 KeV. The Monte Carlo calculations also reproduced the intensity of observed single‐and double‐escape peaks, providing that the effects of positron annihilation‐in‐flight were incorporated. Conclusion: A new method was established. The precise calibration curves obtained from this work are useful for accurate radiation detection and improving quality control to quality assurance (QA) for intensity‐modulated radiation therapy (IMRT). Research sponsored by Department of Energy and Robert Welch Foundation.",
author = "Y. Zhai and L. Trache and R. Tribble and Y. Liu and C. Shi and Nikos Papanikolaou and V. Iacob and J. Hardy and G. Tabacaru",
year = "2008",
doi = "10.1118/1.2961992",
language = "English (US)",
volume = "35",
pages = "2780",
journal = "Medical Physics",
issn = "0094-2405",
publisher = "AAPM - American Association of Physicists in Medicine",
number = "6",

}

TY - JOUR

T1 - SU‐GG‐T‐240

T2 - New Method of An HPGe Detector Precise Efficiency Calibration with Experimental Measurements and Monte Carlo Simulations

AU - Zhai, Y.

AU - Trache, L.

AU - Tribble, R.

AU - Liu, Y.

AU - Shi, C.

AU - Papanikolaou, Nikos

AU - Iacob, V.

AU - Hardy, J.

AU - Tabacaru, G.

PY - 2008

Y1 - 2008

N2 - Purpose: Developing a method of an HPGe detector precise γ efficiency calibration which is very important for accurate radiation detection during cancer radiotherapy practices. Method and Materials: [formula omitted] radioactive nucleus produced and separated with Momentum Achromat Recoil Spectrometer (MARS) at the K500 superconducting cyclotron of Texas A&M University has positron decays followed by γ transitions up to 8 MeV from [formula omitted] excited states, which is used for a β‐γ coincidence measurement with a 1‐mm‐thick BC404 plastic scintillator, an HPGe detector and a fast tape‐transport system to calibrate the HPGe detector. Results: By carefully considering the effects of summing, positron annihilation, internal conversion, and β detector efficiency when analyzing [formula omitted] spectrum, we got the efficiency for γ‐ray 7070 keV at 49 mm distance away from the source sample [formula omitted], which was 0.192(6)%. The Monte Carlo (MC) simulation with CYLTRAN code gave a value of 0.189%, which was in agreement with our measurements. The precise efficiency calibration curve of the HPGe detector up to 7070 KeV at 49 mm distance away from the source sample was obtained. By using the same procedure, we got the efficiency for the 7070 keV γ‐ray at 151 mm distance away from the source sample [formula omitted], which was 0.0385(8)%. MC simulation value was 0.0399%, which differed from measurement by 4(2)%. This discrepancy led us to assign an uncertainty of 4% to our efficiencies at 151 mm up to 7070 KeV. The Monte Carlo calculations also reproduced the intensity of observed single‐and double‐escape peaks, providing that the effects of positron annihilation‐in‐flight were incorporated. Conclusion: A new method was established. The precise calibration curves obtained from this work are useful for accurate radiation detection and improving quality control to quality assurance (QA) for intensity‐modulated radiation therapy (IMRT). Research sponsored by Department of Energy and Robert Welch Foundation.

AB - Purpose: Developing a method of an HPGe detector precise γ efficiency calibration which is very important for accurate radiation detection during cancer radiotherapy practices. Method and Materials: [formula omitted] radioactive nucleus produced and separated with Momentum Achromat Recoil Spectrometer (MARS) at the K500 superconducting cyclotron of Texas A&M University has positron decays followed by γ transitions up to 8 MeV from [formula omitted] excited states, which is used for a β‐γ coincidence measurement with a 1‐mm‐thick BC404 plastic scintillator, an HPGe detector and a fast tape‐transport system to calibrate the HPGe detector. Results: By carefully considering the effects of summing, positron annihilation, internal conversion, and β detector efficiency when analyzing [formula omitted] spectrum, we got the efficiency for γ‐ray 7070 keV at 49 mm distance away from the source sample [formula omitted], which was 0.192(6)%. The Monte Carlo (MC) simulation with CYLTRAN code gave a value of 0.189%, which was in agreement with our measurements. The precise efficiency calibration curve of the HPGe detector up to 7070 KeV at 49 mm distance away from the source sample was obtained. By using the same procedure, we got the efficiency for the 7070 keV γ‐ray at 151 mm distance away from the source sample [formula omitted], which was 0.0385(8)%. MC simulation value was 0.0399%, which differed from measurement by 4(2)%. This discrepancy led us to assign an uncertainty of 4% to our efficiencies at 151 mm up to 7070 KeV. The Monte Carlo calculations also reproduced the intensity of observed single‐and double‐escape peaks, providing that the effects of positron annihilation‐in‐flight were incorporated. Conclusion: A new method was established. The precise calibration curves obtained from this work are useful for accurate radiation detection and improving quality control to quality assurance (QA) for intensity‐modulated radiation therapy (IMRT). Research sponsored by Department of Energy and Robert Welch Foundation.

UR - http://www.scopus.com/inward/record.url?scp=85024804308&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85024804308&partnerID=8YFLogxK

U2 - 10.1118/1.2961992

DO - 10.1118/1.2961992

M3 - Article

AN - SCOPUS:85024804308

VL - 35

SP - 2780

JO - Medical Physics

JF - Medical Physics

SN - 0094-2405

IS - 6

ER -