Fig. 4: Two-dimensional depth sensing and coincident pulse shape analysis.

a Schematic diagram of the typical interaction positions. b Energy spectrum achieved from position ii. The inset shows a scatter plot of the pulse amplitude of the Au cathode versus the drift time (viz., interaction depth). c Energy spectrum achieved from position i. Insert was the scatter plot of the pulse amplitude of Au cathode versus the drift time. d–g Typical pulses collected from four different interaction positions. h–k Scatter plot of the Au cathode amplitude, EGI anode amplitude and ACR versus drift time, and the corresponding energy spectrum by cathode signal of 10.2 mm thick detector I with applied bias of 500 V for ¹³⁷Cs γ ray source. l–o Scatter plot of Au cathode amplitude, EGI anode amplitude and ACR versus drift time, and corresponding energy spectrum of the cathode signal of 22.1 mm thick detector III with an applied bias of 800 V for the ¹³⁷Cs γ ray source. Note that the triggered signals are those of EGI anode and that the pulse height and drift time are directly measured from digitized pulses. The energy spectra were generated according to the raw statistical distributions of the pulse amplitude without any calibration. The dashed lines in h–j and l–n represent the position of the EGI anode.