2πα and 2πβ experimental data set

Data acquisition methods: In this study, the detector employed was a large-area 2π multi-wire proportional counter, a product of the China Institute of Atomic Energy (CIAE). The detector operates at voltages of 2100 V for α sources and 2800 V for β sources. It boasts a counting response uniformity exceeding ±0.4%, an effective detection area of approximately 1400 cm2, short-term stability measurements surpassing 0.3% over 8 h, and long-term stability measurements surpassing 0.8% over a year. A schematic of the 2π multi-wire proportional counter system used in this study is shown in Figure 1. The counter utilized P-10 gas for counting, composed of 90% Ar and 10% CH4. The gas flow rate was consistently held at 20–60 mL/min during the detector's routine operation. All sources deployed in the experiments were calibrated, with their traces leading back to the 2πα and 2πβ surface emission rate standard devices at CIAE. To align the count rate recorded by the digital acquisition card with the plane sources' surface emission rate, the acquisition card's pulse amplitude trigger threshold was adjusted during the surface emission rate calibration experiments. For configuring the acquisition card, a fixed sampling length was determined based on the pulse's maximum width. A pertinent starting point for sampling was selected. Amplitude and time resolutions were fine-tuned to prevent signal saturation and to ensure comprehensive pulse signal capture across all plane source varieties. Each signal sample spanned 1048 ns, with a time step of 1 ns, and it was divided into 1048 equidistant components. This type of configurations implied that minimal saturation or signal pile-up was observed throughout data collection. Description of the two files: The "α-plane source data" is a set of vectors converted from the digital signals of two α-plane sources (238Pu and 241Am) and one β-plane source (204Tl) at 2100V. The "β-plane source data" is a set of vectors converted from the digital signals of two α-plane sources (204Tl and 90Sr) and one α-plane source (241Am) at 2100V. In both files, the values in the first 1048 columns are the height information of the pulse and the 1049th column is the classification number (1, 2, 3).