Mengzhao Li
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Mengzhao Li has a total of 86 co-authors. Here are the top co-authors by number of shared publications:
Zhijun Liang
Institute of High Energy Physics, Chinese Academy of Sciences
10 shared publicationsShuqi Li
Institute of High Energy Physics Chinese Academy of Sciences 100049 Beijing China
8 shared publicationsXuan Yang
Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
8 shared publications- Mei Zhao
Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
7 shared publications Bo Liu
Institute of High Energy Physics Chinese Academy of Sciences 19B Yuquan Road 100049 Beijing China
6 shared publications- Weiyi Sun
Chinese Academy of Sciences
6 shared publications
Latest Publications
- 1 October 2026
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Electron Devices
- Vol. 73 (10) , 6151-6159
Temperature Dependence of Gain and Time Resolution in LGAD Detectors
- 1 October 2026
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Electron Devices
- Vol. 73 (10) , 6151-6159
Temperature Dependence of Gain and Time Resolution in LGAD Detectors
- Open Access
Investigation of Position-Dependent Signal Propagation Delay in Large-Pitch AC-LGAD Using a Two-Dimensional Transmission-Line Model
This paper presents a study of position-dependent signal propagation delay in large-pitch pixelated AC-coupled Low-Gain Avalanche Detectors (AC-LGADs). In AC-LGADs, a continuous resistive layer and segmented AC-coupled readout electrodes enable charge sharing and simultaneous timing and position measurements. However, lateral signal transport in the resistive layer can introduce a position-dependent delay in the measured signal arrival time. In this work, an IHEP-designed pixel AC-LGAD was characterized using a two-dimensional picosecond laser scan. The measured leading-edge arrival time shows an approximately linear dependence on an effective propagation distance, with a delay slope of about for the tested device. After applying a position-dependent delay correction, the sigma of the combined arrival-time distribution over the scanned region is reduced from 88.3 ps to 48.6 ps. To interpret the observed delay, an equivalent two-dimensional lossy transmission-line model is developed for the continuous resistive layer. The model provides a semi-quantitative description of the leading-edge delay and indicates that, within the measured signal bandwidth, the transport is dominated by the resistive term and is therefore dispersive and diffusion-like. A distributed SPICE network including the pad-area response and capacitive charge sharing provides a complementary circuit-level cross-check of the approximately linear distance dependence. These results quantify the propagation-induced timing delay in large-pitch AC-LGADs and provide guidance for timing correction and future optimization of the resistive-layer sheet resistance.Open AccessInvestigation of Position-Dependent Signal Propagation Delay in Large-Pitch AC-LGAD Using a Two-Dimensional Transmission-Line Model
This paper presents a study of position-dependent signal propagation delay in large-pitch pixelated AC-coupled Low-Gain Avalanche Detectors (AC-LGADs). In AC-LGADs, a continuous resistive layer and segmented AC-coupled readout electrodes enable charge sharing and simultaneous timing and position measurements. However, lateral signal transport in the resistive layer can introduce a position-dependent delay in the measured signal arrival time. In this work, an IHEP-designed pixel AC-LGAD was characterized using a two-dimensional picosecond laser scan. The measured leading-edge arrival time shows an approximately linear dependence on an effective propagation distance, with a delay slope of about for the tested device. After applying a position-dependent delay correction, the sigma of the combined arrival-time distribution over the scanned region is reduced from 88.3 ps to 48.6 ps. To interpret the observed delay, an equivalent two-dimensional lossy transmission-line model is developed for the continuous resistive layer. The model provides a semi-quantitative description of the leading-edge delay and indicates that, within the measured signal bandwidth, the transport is dominated by the resistive term and is therefore dispersive and diffusion-like. A distributed SPICE network including the pad-area response and capacitive charge sharing provides a complementary circuit-level cross-check of the approximately linear distance dependence. These results quantify the propagation-induced timing delay in large-pitch AC-LGADs and provide guidance for timing correction and future optimization of the resistive-layer sheet resistance. - 12 August 2026
- Published by Springer Nature in Nuclear Science and Techniques
- Vol. 37 (11) , 222
Development of a strip LGAD sensor with double-end readout for future colliders
- 12 August 2026
- Published by Springer Nature in Nuclear Science and Techniques
- Vol. 37 (11) , 222
Development of a strip LGAD sensor with double-end readout for future colliders
- 24 July 2024
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Nuclear Science
- Vol. 71 (9) , 2109-2115
Test of the Performance of an LGAD-Based Zero-Degree Detector on the CSNS Back-n Beamline
A comprehensive and reliable nuclear database of neutron-induced processes is required by the development of Accelerator-Driven System technology. Although many efforts have been made, the measurements of light charged ions (such as proton, tritium and α) in zero degree of the beam direction were not conducted with a high accuracy. Most detectors can not work constantly under the strike of intense flux neutron beam, thus their application as Zero Degree Detector (ZDD) is greatly limited. Recently, the Low Gain Avalanche Diode (LGAD) technology has been developed to meet the harsh requirement of the ATLAS on the high-luminosity phase of the Large Hadron Collider (LHC), and could survive after 2.5×10 15 1-MeV n eq /cm 2 irradiation. With its 50 μm active thickness, 30 ps timing resolution, low cost and good radiation hardness property, the LGAD detector is expected to be a candidate for the use of a Zero Degree Detector in neutron-induced processes data measurements. This paper represents a performance test of the LGAD detector when it is used as a ZDD on the Back-streaming Neutron (Back-n) beamline at CSNS. Based on the measurements of the cross section of 6 Li(n,T)α, it shows that the LGAD performs well as a ZDD based on a good agreement with the data from Evaluated Nuclear Data File (ENDF).
- 24 July 2024
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Nuclear Science
- Vol. 71 (9) , 2109-2115
Test of the Performance of an LGAD-Based Zero-Degree Detector on the CSNS Back-n Beamline
A comprehensive and reliable nuclear database of neutron-induced processes is required by the development of Accelerator-Driven System technology. Although many efforts have been made, the measurements of light charged ions (such as proton, tritium and α) in zero degree of the beam direction were not conducted with a high accuracy. Most detectors can not work constantly under the strike of intense flux neutron beam, thus their application as Zero Degree Detector (ZDD) is greatly limited. Recently, the Low Gain Avalanche Diode (LGAD) technology has been developed to meet the harsh requirement of the ATLAS on the high-luminosity phase of the Large Hadron Collider (LHC), and could survive after 2.5×10 15 1-MeV n eq /cm 2 irradiation. With its 50 μm active thickness, 30 ps timing resolution, low cost and good radiation hardness property, the LGAD detector is expected to be a candidate for the use of a Zero Degree Detector in neutron-induced processes data measurements. This paper represents a performance test of the LGAD detector when it is used as a ZDD on the Back-streaming Neutron (Back-n) beamline at CSNS. Based on the measurements of the cross section of 6 Li(n,T)α, it shows that the LGAD performs well as a ZDD based on a good agreement with the data from Evaluated Nuclear Data File (ENDF).
- Open Access
The Performance of AC-coupled Strip LGAD developed by IHEP
The AC-coupled Strip LGAD (Strip AC-LGAD) is a novel LGAD design that diminishes the density of readout electronics through the use of strip electrodes, enabling the simultaneous measurement of time and spatial information. The Institute of High Energy Physics has designed a long Strip AC-LGAD prototype with a strip electrode length of 5.7 mm and pitches of 150 $μm$, 200 $μm$, and 250 $μm$. Spatial and timing resolutions of the long Strip AC-LGAD are studied by pico-second laser test and beta source tests. The laser test demonstrates that spatial resolution improves as the pitch size decreases, with an optimal resolution achieved at 8.3 $μ$m. Furthermore, the Beta source test yields a timing resolution of 37.6 ps.Open AccessThe Performance of AC-coupled Strip LGAD developed by IHEP
The AC-coupled Strip LGAD (Strip AC-LGAD) is a novel LGAD design that diminishes the density of readout electronics through the use of strip electrodes, enabling the simultaneous measurement of time and spatial information. The Institute of High Energy Physics has designed a long Strip AC-LGAD prototype with a strip electrode length of 5.7 mm and pitches of 150 $μm$, 200 $μm$, and 250 $μm$. Spatial and timing resolutions of the long Strip AC-LGAD are studied by pico-second laser test and beta source tests. The laser test demonstrates that spatial resolution improves as the pitch size decreases, with an optimal resolution achieved at 8.3 $μ$m. Furthermore, the Beta source test yields a timing resolution of 37.6 ps. - Open Access
Development of the strip LGAD detector with double-end readout for future colliders
The Low-Gain Avalanche Diode (LGAD) is a new silicon detector and holds wide application prospects in particle physics experiments due to its excellent timing resolution. The LGAD with a pixel size of 1.3 mm $\times$ 1.3 mm was used to construct a High Granularity Timing Detector (HGTD) in ATLAS experiments to solve the pile-up problem. Meanwhile, the Circular Electron Positron Collider (CEPC) also proposes detectors using the LGAD. However, pixel LGAD exhibits higher readout electronics density and cost, which somewhat limits the application of LGADs. To decrease the readout electronics density, the Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences has designed strip LGADs with larger areas. These strip LGADs are all 19 mm in length but with different widths of 1.0 mm, 0.5 mm, and 0.3 mm. This article provides a detailed introduction to the design parameters of these strip LGADs and tests their electrical characteristics, including leakage current, break-down voltage, depletion capacitance, etc. The timing resolution and signal-to-noise ratio of the three strip LGAD sensors were investigated using a beta source test system. The position resolution parallel to the strip direction was tested and analyzed for the first time using a pico-second laser test system. Tests have demonstrated that the timing resolution of strip LGADs can reach about 37.5 ps, and position resolution parallel to the strip direction is better than 1 mm.Open AccessDevelopment of the strip LGAD detector with double-end readout for future colliders
The Low-Gain Avalanche Diode (LGAD) is a new silicon detector and holds wide application prospects in particle physics experiments due to its excellent timing resolution. The LGAD with a pixel size of 1.3 mm $\times$ 1.3 mm was used to construct a High Granularity Timing Detector (HGTD) in ATLAS experiments to solve the pile-up problem. Meanwhile, the Circular Electron Positron Collider (CEPC) also proposes detectors using the LGAD. However, pixel LGAD exhibits higher readout electronics density and cost, which somewhat limits the application of LGADs. To decrease the readout electronics density, the Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences has designed strip LGADs with larger areas. These strip LGADs are all 19 mm in length but with different widths of 1.0 mm, 0.5 mm, and 0.3 mm. This article provides a detailed introduction to the design parameters of these strip LGADs and tests their electrical characteristics, including leakage current, break-down voltage, depletion capacitance, etc. The timing resolution and signal-to-noise ratio of the three strip LGAD sensors were investigated using a beta source test system. The position resolution parallel to the strip direction was tested and analyzed for the first time using a pico-second laser test system. Tests have demonstrated that the timing resolution of strip LGADs can reach about 37.5 ps, and position resolution parallel to the strip direction is better than 1 mm. - Open Access
- 23 June 2023
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Nuclear Science
- Vol. 70 (8) , 2134-2138
The Performance of Large-Pitch AC-LGAD With Different N+ Dose
AC-Coupled LGAD (AC-LGAD) is a new 4D detector developed based on the Low Gain Avalanche Diode (LGAD) technology, which can accurately measure the time and spatial information of particles. The Institute of High Energy Physics (IHEP) designed a large-size AC-LGAD with a pitch of 2000 μm and AC pad of 1000 μm, and explored the effect of N+ layer dose on the spatial resolution and time resolution. The spatial resolution varied from 36 μm to 16 μm depending on N+ dose for a charge corresponding to about 12 minimum ionizing particles. The jitter component of the time resolution does not change significantly with different N+ doses, and it is about 15-17 ps measured by laser. The AC-LGAD with a low N+ dose has a large attenuation factor and better spatial resolution in the central region between pads. In these specific conditions, large signal attenuation factor and low noise level are beneficial to improve the spatial resolution of the AC-LGAD sensor.
- 23 June 2023
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Nuclear Science
- Vol. 70 (8) , 2134-2138
Open AccessThe Performance of Large-Pitch AC-LGAD With Different N+ Dose
AC-Coupled LGAD (AC-LGAD) is a new 4D detector developed based on the Low Gain Avalanche Diode (LGAD) technology, which can accurately measure the time and spatial information of particles. The Institute of High Energy Physics (IHEP) designed a large-size AC-LGAD with a pitch of 2000 μm and AC pad of 1000 μm, and explored the effect of N+ layer dose on the spatial resolution and time resolution. The spatial resolution varied from 36 μm to 16 μm depending on N+ dose for a charge corresponding to about 12 minimum ionizing particles. The jitter component of the time resolution does not change significantly with different N+ doses, and it is about 15-17 ps measured by laser. The AC-LGAD with a low N+ dose has a large attenuation factor and better spatial resolution in the central region between pads. In these specific conditions, large signal attenuation factor and low noise level are beneficial to improve the spatial resolution of the AC-LGAD sensor.