arXiv subjects

De Zhang

Publications and source records attributed to De Zhang.

4 recordsLinked to original sources

arXiv2026

Time performance of USTC-IME LGAD under synchrotron light source focused X-ray

The time performance of Low Gain Avalanche Diodes (LGADs), designed by the University of Science and Technology of China (USTC) and fabricated by the Institute of Microelectronics of Chinese Academy of Sciences (IME), was characterized at the Shanghai Synchrotron Radiation Facility (SSRF). The experiment was conducted at the BL16B1 beamline, which delivers a focused X-ray beam with a diameter of 500 {\mu}m, a repetition period of 2 ns, and a photon energy of 10 keV. Using a fast oscilloscope, waveforms containing continuous signal pulses were recorded within a 50 ns time window. The LGAD under test successfully resolved the 2 ns period of the SSRF. To mitigate pile-up effects and extract pulse-by-pulse information from the acquired waveforms, a waveform-level global template fitting method was employed. The time resolution was then estimated using a combined profile likelihood approach, yielding a value of 126.6 ps. The effect of random photon absorption depth on the time resolution of LGADs was studied through dedicated simulations.

physics.ins-det↗

arXiv2026

A High Gain Preamplifier Board for Low Charge Semiconductor Detectors

We present a high-gain, low-noise preamplifier board designed for reading out low-charge semiconductor detectors--specifically Low-Gain Avalanche Detectors (LGADs) and three-dimensional (3D) silicon sensors--in high-energy physics applications. The circuit employs a three-stage architecture featuring a discrete SiGe:C bipolar junction transistor (BJT)-based transimpedance amplifier (TIA) front-end followed by two resistive feedback amplification stages using LTC6431 chips. This configuration achieves a charge gain of 115.27 mV ns/fC with excellent linearity over an input range of 0.5 fC to 25 fC and a wide bandwidth spanning from 34.0 MHz to 594.3 MHz. Experimental evaluations coupled with LGAD detectors demonstrate a time resolution of 36.41 ps and an equivalent noise charge (ENC) of 0.18 fC at 20 {\deg}C. Furthermore, tests with conventional PIN sensors without a gain layer yield a timing resolution of 76.10 ps with an ENC of 0.10 fC, and tests with the 3D silicon detector yield 39.40 ps with an ENC of 0.09 fC, all measured under the same thermal condition. All configurations confirm the board's capability in low-signal regimes, significantly outperforming previous reference designs. A six-channel variant of the board has also been developed to support position-sensitive measurements. These findings demonstrate the board's suitability for laboratory-based 4D tracking detector characterisation, while simultaneously providing the groundwork for dedicated ASIC development.

physics.ins-det↗

arXiv2026

Development of Small-pitch, Ultra-thin 3D Silicon Sensors at USTC

We report on the development of 3D silicon sensors at the University of Science and Technology of China (USTC). The sensor involves columnar electrodes (5 um in diameter) of both doping types, etched from the same wafer side. The p+ electrodes pass through the epitaxial wafer, whereas the n+ electrodes stop at a short distance from the opposite side of the epitaxial wafer. With respect to previous generations of 3D sensors, they feature an ultra-thin active substrate (50 um) and a small pixel size of 50 um x 50 um or 25 um x 25 um. This R&D project aims to establish a sensor technology to simultaneously measure position and time information at the single-pixel level. The first run with one merged wafer layout has been completed. The design, fabrication, and characterization of the sensors are reported in this paper.

physics.ins-det↗

arXiv2025

Performance of USTC first batch resistive AC-LGAD sensor

In this paper, the design and characterization of AC-LGAD sensors at the University of Science and Technology of China is introduced. The sensors are characterized with an infrared laser Transient Current Technique (TCT) system for evaluating signal response characteristics and spatial resolution. The temporal resolution was quantified with electrons emitted by a Sr-90 radioactive source. The spatial resolution can reach 4 {\mu}m and a temporal resolution of 48 ps is achieved

physics.ins-det↗