The Origin Clustering and Detected Data of the Large-Pixel Two-Layer LaBr3 Compton Camera Prototype

This data set is the original data of the calibration and positioning experiment of the large pixel double-layer Lanthanum(III) bromide Compton camera prototype developed by the Particle Information Acquisition and Processing Laboratory of the Department of Engineering Physics, Tsinghua University. Compton camera is a gamma camera that uses electronic collimation to locate radioactive sources. After photons enter the Compton camera, the camera records the energy deposited by the Compton scattering of photons and the Photoelectric effect of the scattered photons. According to the one-to-one correspondence between the scattering angle and the energy of the scattered photons in the Compton scattering, the photon incidence position can be limited to a cone (i.e. the Compton cone). The Compton camera on which this data is based is a double-layer Compton camera. The location and deposition energy information of Compton scattering and photoelectric absorption are obtained through two sets of detector units. The detector unit consists of 10 × The Lanthanum(III) bromide crystal array, silicon Photomultiplier tube, organic glass visible light refracting plate and corresponding encoding circuit (resistance weight network circuit) are composed. The length and width of Lanthanum(III) bromide crystal are all 5 mm, the thickness of the first layer (scattering layer) is 5 mm, and the thickness of the second layer (absorption layer) is 10 mm; The silicon Photomultiplier tube is 8 × 8 arrays; Organic glass is used to disperse visible photons generated by scintillators; The encoding circuit converts 64 voltage signals generated by the silicon Photomultiplier tube into 4 voltage signals for output according to the spatial position relationship. The data in this dataset is arranged in a folder list, with each folder representing a measurement. The data is stored in the "Energy. txt" file within the folder; The output signal in the file is in the form of a list of data, with 9 integers representing one photon event per line. The specific meanings are timestamp, scattering layer 4-channel voltage signal address, and absorption layer 4-channel voltage signal address. By using the four voltage signals of the detector unit, the photon action position can be obtained using the center of gravity weight method; Meanwhile, the sum of the four signals serves as the total energy of photon deposition. The calibration data in this dataset was experimentally obtained on December 12, 2022 at the factory of Jinhong Crystal Materials (Shanghai) Co., Ltd. Three point-like isotropic radiation sources, 137Cs, 22Na, and 57Co, were used and measured at a distance of 5 cm from both sets of detector units. All three radiation sources measured 20 million events. The experimental data in this dataset was obtained from December 6-10, 2022 at the factory of Jinhong Crystal Materials (Shanghai) Co., Ltd. The measurement object was a 137Cs source; In the experiment, a Compton camera was assembled with a scattering layer 5 cm away from the absorption layer, with its center on the same axis; The radiation source is 5 cm away from the surface of the scattering layer along this axis direction. The experiment measured three sets of data: the radiation source is located on the axis, 5 cm to the left of the axis, and above the right of the axis (with a horizontal distance of 5 cm and a vertical distance of 5 cm). The output voltage signal of this dataset has a baseline drift error of less than 200 channels, and the resistance value of the decoding circuit has an error of one thousandth; After calibration calculation, the energy resolution of two groups of Lanthanum(III) bromide array detector units is 7.65% and 8.44% @ 511 keV.