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Spectrometric methods used in the calibration of radiodiagnostic measuring instruments

Abstract

Recently a set of parameters for checking the quality of radiation for use in diagnostic radiology was established at the calibration facility of Nederlands Meetinstituut (NMI). The establishment of the radiation quality required re-evaluation of the correction factors for the primary air-kerma standards. Free-air ionisation chambers require several correction factors to measure air-kerma according to its definition. These correction factors were calculated for the NMi free-air chamber by Monte Carlo simulations for monoenergetic photons in the energy range from 10 keV to 320 keV. The actual correction factors follow from weighting these mono-energetic correction factors with the air-kerma spectrum of the photon beam. This paper describes the determination of the photon spectra of the X-ray qualities used for the calibration of dosimetric instruments used in radiodiagnostics. The detector used for these measurements is a planar HPGe-detector, placed in the direct beam of the X-ray machine. To convert the measured pulse height spectrum to the actual photon spectrum corrections must be made for fluorescent photon escape, single and multiple compton scattering inside the detector, and detector efficiency. From the calculated photon spectra a number of parameters of the X-ray beam can be calculated. The calculated first and second half value layer  More>>
Authors:
De Vries, W [1] 
  1. Rijksuniversiteit Utrecht (Netherlands)
Publication Date:
Dec 01, 1995
Product Type:
Conference
Report Number:
INIS-BE-0001; CONF-951246-
Reference Number:
SCA: 550603; PA: AIX-28:034233; EDB-97:069800; SN: 97001775002
Resource Relation:
Conference: 11. annual symposium of the Belgian Association of Hospital Physicists: conformal radiotherapy - physics, treatment planning and verification, Ghent (Belgium), 8-9 Dec 1995; Other Information: PBD: Dec 1995; Related Information: Is Part Of Conformal Radiotherapy: Physics, Treatment Planning and Verification. Proceedings book; De Wagter, C. [ed.]; PB: 273 p.
Subject:
55 BIOLOGY AND MEDICINE, BASIC STUDIES; BIOMEDICAL RADIOGRAPHY; RADIOTHERAPY; BEAM OPTICS; CONFORMAL MAPPING; DOSIMETRY; IMAGE PROCESSING; IMAGE SCANNERS; ISODOSE CURVES; QUALITY ASSURANCE
OSTI ID:
464328
Research Organizations:
Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde
Country of Origin:
Belgium
Language:
English
Other Identifying Numbers:
Other: ON: DE97622340; TRN: BE9700033034233
Availability:
INIS; OSTI as DE97622340
Submitting Site:
BEN
Size:
pp. 217-221
Announcement Date:

Citation Formats

De Vries, W. Spectrometric methods used in the calibration of radiodiagnostic measuring instruments. Belgium: N. p., 1995. Web.
De Vries, W. Spectrometric methods used in the calibration of radiodiagnostic measuring instruments. Belgium.
De Vries, W. 1995. "Spectrometric methods used in the calibration of radiodiagnostic measuring instruments." Belgium.
@misc{etde_464328,
title = {Spectrometric methods used in the calibration of radiodiagnostic measuring instruments}
author = {De Vries, W}
abstractNote = {Recently a set of parameters for checking the quality of radiation for use in diagnostic radiology was established at the calibration facility of Nederlands Meetinstituut (NMI). The establishment of the radiation quality required re-evaluation of the correction factors for the primary air-kerma standards. Free-air ionisation chambers require several correction factors to measure air-kerma according to its definition. These correction factors were calculated for the NMi free-air chamber by Monte Carlo simulations for monoenergetic photons in the energy range from 10 keV to 320 keV. The actual correction factors follow from weighting these mono-energetic correction factors with the air-kerma spectrum of the photon beam. This paper describes the determination of the photon spectra of the X-ray qualities used for the calibration of dosimetric instruments used in radiodiagnostics. The detector used for these measurements is a planar HPGe-detector, placed in the direct beam of the X-ray machine. To convert the measured pulse height spectrum to the actual photon spectrum corrections must be made for fluorescent photon escape, single and multiple compton scattering inside the detector, and detector efficiency. From the calculated photon spectra a number of parameters of the X-ray beam can be calculated. The calculated first and second half value layer in aluminum and copper are compared with the measured values of these parameters to validate the method of spectrum reconstruction. Moreover the spectrum measurements offer the possibility to calibrate the X-ray generator in terms of maximum high voltage. The maximum photon energy in the spectrum is used as a standard for calibration of kVp-meters.}
place = {Belgium}
year = {1995}
month = {Dec}
}