Weight-percent analysis for prompt gamma neutron activation substance analyzers

A PGNAA (Prompt-Gamma, Neutron-Activation Analysis) substance analyzer comprising:

• an isotopic radioactive source of neutrons;
• a neutron moderating material arranged with respect to the isotopic radioactive source to slow velocities of neutrons from the isotopic radioactive source;
• an opening arranged with respect to the source of neutrons to receive a substance;
• a gamma ray detector arranged with respect to the opening to detect gamma rays emanating at least from the substance in response to absorption of neutrons by the substance;
• and
• one or more computational devices configured to
• receive spectral data of the detected gamma rays,
• perform a regression algorithm on the spectral data using a data repository of spectral responses for known atomic elements to determine coefficients of spectrum for atomic elements detected in the spectral data,
• use the coefficients of spectrum directly as effective weight values of the atomic elements detected in the spectral data,
• sum the effective weight values together to form a total effective weight value for the substance being analyzed,
• divide each of two or more of the effective weight values by the total effective weight value for the substance being analyzed to generate effective weight-percent values for the atomic elements detected in the spectral data, and
• generate molecular weight-percent values from the effective weight-percent values, for the substance being analyzed, based on a correlation of (a) previous effective weight-percent values obtained for known samples with (b) molecular weight-percent values obtained for the known samples.

A non-transitory machine readable medium encoding instructions operable to receive PGNAA (Prompt-Gamma, Neutron-Activation Analysis) spectral data and to cause a computer to perform operations comprising:

• running a regression algorithm on the PGNAA spectral data using a data repository of spectral responses for known atomic elements to determine coefficients of spectrum for atomic elements detected in the PGNAA spectral data;
• summing effective weight values, corresponding to the coefficients of spectrum, together to form a total effective weight value for the substance being analyzed;
• dividing each of two or more of the effective weight values by the total effective weight value for the substance being analyzed to generate effective weight-percent values corresponding to two or more respective ones of the atomic elements detected in the PGNAA spectral data;
• and
• generating final weight-percent values from the effective weight-percent values, for the substance being analyzed, in accordance with calibration data generated by correlating effective weight-percent values obtained for known samples with elemental or molecular weight-percent values obtained previously for the known samples.

A non-transitory machine readable medium encoding instructions operable to receive PGNAA (Prompt-Gamma, Neutron-Activation Analysis) spectral data and to cause a computer to perform operations comprising:

• running a regression algorithm on the PGNAA spectral data using a data repository of spectral responses for known atomic elements to determine coefficients of spectrum for atomic elements detected in the PGNAA spectral data;
• summing the coefficients of spectrum together to form a total effective weight value for the substance being analyzed;
• dividing each of two or more of the coefficients of spectrum by the total effective weight value for the substance being analyzed to generate effective weight-percent values for the atomic elements detected in the PGNAA spectral data;
• and
• generating molecular weight-percent values from the effective weight-percent values, for the substance being analyzed, in accordance with calibration data generated by correlating effective weight-percent values obtained for known samples with molecular weight-percent values obtained previously for the known samples.