The variety and content of minerals in clay determine its quality and use. The x‐ray fluorescence characteristics of seven elements, that is, Mg, Al, Si, K, Ca, Ti, and Fe, in clay samples were studied using the energy‐dispersive x‐ray fluorescence (EDXRF) method. The application of wavelet transform was used to analyze the overlapping peaks of the FeKα and MnKβ and the CaKα and KKβ spectral lines and to measure the spectral peak count rate and the content of seven elements. The weight of classified elements in clay was calculated through principal component analysis, and the clay samples from four clay‐producing areas were classified using the K‐means clustering method. The results showed that the accuracy of classification using the count rate of seven elements reached 97.73%. The average accuracy of the classification results of the content of seven elements reached 80.68%. A comparison of the results showed that the EDXRF spectral peak information provides a reliable scientific method for the identification and tracing of clay and its products. In addition, tracing the origin of clay and its products can also indirectly assess the radiation level and its impact on the radiation environment based on the radiation index test results.

NaI(Tl) detectors are frequently operated under unstable temperature conditions when used in an open environment. Temperature changes would result in a peak shift and spectral distortion during measurement. Two easy-to-implement methodologies are proposed to stabilize the measured spectrum without the necessity of adjusting the gain, which are a correction algorithm for temperature-caused peak-shift based on multiple characteristic peak area weighting factors and an interpolation correction algorithm based on multicharacteristic peak sequence. Both of them can be used when the relative channel displacement of characteristic peaks in the spectrum due to temperature changes is not constant. Experimental data obtained under controlled temperature conditions in the laboratory were adopted to correct a spectrum, with joint consideration of some known characteristic peaks, such as 40K, U (214Bi), or Th (208Tl) peaks. Through constructing a reversible temperature coefficient matrix, one can easily obtain the coefficients of the n-th polynomial describing the influence of temperature on peak position, which presents their nonlinear mathematical relationship. Then, corrections of these two effects can also be easily calculated. Comparing the experimental results, peak positions before and after correction, it is proved that the interpolation correction algorithm based on multicharacteristic peak sequence has better correction accuracy, but the temperature-caused peak shift correction algorithm based on the multicharacteristic peak area weighting factor has a shorter calibration time.

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A digital nuclear pulse and digital nuclear energy spectrum signal generator was designed using FPGA and digital frequency synthesizer (DDS). It also includes slip signal, triangle wave, square wave, sine wave output. By randomly sampling the amplitude information and time information of the reference spectrum line, the complex algorithm of nuclear signal reproduction is avoided, and the simulation of the nuclear signal random pulse and nuclear energy spectrum (137Cs gamma spectrum) is realized. The signal amplitude is adjustable from 0.1V to 10V, and the frequency is adjustable from 10Hz to 10kHz.