IAEA 1995 Intercomparison Spectra

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These spectra were created at the Technical University of Delft and used in the 1995 IAEA intercomparison of software for gamma-ray spectrum analysis. The references to this are below.

Details of the spectra are given on TUD website and reproduced partly here. Please note that these spectra are made available to you on this site by permission of Menno Blaauw as a private person, not under the aegis of the IAEA. The spectra were created as ASCII text files. I have converted those to Canberra MCA format and ORTEC CHN and SPC formats.

The spectrometer gain used results in 2.5 channels per keV, which is both realistic and near optimum. The only unphysical properties of the reference spectra are doublets of two 511 keV peaks in the added spectra, and unrealistic ADC-threshold edges. There is a variety of peaks present, ranging from highy significant to undetectable, on low and high backgrounds - whatever you wish to test.

The following files are available for download. With the exception of the textual ReadMe file, all are .ZIP files containing all the original files plus converted spectra in the specified format.

Please note the converted spectra are provided in good faith and are believed to be accurate. No responsibity for adverse consequences if that is found not to be the case.

These spectra come with reference lists of peak energies and areas, determined from a spectrum that was counted 20 times longer than the test spectra. In May 1998, it was shown that these reference peak areas are correct in an absolute sense in two papers referred to below. The spectra do come with a PC-program to compare any analysis results with the reference results in a statistical sense.

What you get

The spectra consist of:


calibration spectrum containing Co-57, Cs-137, Na-22, Mn-54 and Co-60.


Ra-226 + progeny spectrum, counted 2000 s.


same, but counted in the presence of a Am-241 source to induce high-energy tailing.


Sum of two Ra-226 spectra, one of them shifted by 1 channel to the right. Four other spectra are available with different peak ratios, i.e. 1:3, 3:1, 10:1 and 1:100.


IAEA gamma-ray spectra for testing of spectrum analysis software
M. Blaauw, V. Osorio Fernandez, W. Westmeier
Nucl.Instr.Meth. A387 (1997) 410-415

The 1995 IAEA intercomparison of gamma-ray spectrum analysis software
M. Blaauw, V. Osorio Fernandez, P. van Espen, G. Bernasconi, R. Capote, Noy, H. Manh Dung and N.I. Molla,
Nucl. Instr. Meth. A387 (1997) 416-432

The Reference Peak Areas of the 1995 Test Spectra for Gamma-Ray Spectum Analysis Programs are Absolute and Traceable
M. Blauuw
Nucl. Instrum. Meth, A432 (1999) 74-76

Intercomparison of gamma ray analysis software packages (with companion diskette containing a set of test spectra and programs used for analysis)
IAEA-TECDOC-1011, April 1998

Software for nuclear spectrometry
IAEA-TECDOC-1049, October 1998

Specialized software utilities for gamma ray spectrometry, Final report of a co-ordinated research project
IAEA-TECDOC-1275, March 2002

Internet Resources:

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