Liyuan Zhang - Academia.edu (original) (raw)

Papers by Liyuan Zhang

arXiv: Strongly Correlated Electrons, 2020

The phonon hydrodynamic system has only been detected experimentally in the limited compounds bec... more The phonon hydrodynamic system has only been detected experimentally in the limited compounds because of its stringent condition to appear. Herein, we elucidate the existence of hydrodynamic features driven by the collective excitation of Dirac fluid in semimetal ZrTe5. By measuring the electrical and the thermal property in a wide temperature range, we find the regime as satisfying phonon hydrodynamic-like characteristics with two representative experimental evidence: faster evolution of thermal conductivity than the ballistic regime and the existence of a local maximum of effective mean-free-path. Unlike the phononic hydrodynamics, a magnitude of hundreds violated Wiedemann-Franz law, and phonon-dragged anomalies can be seen, which provide us as a signature of the Dirac fluid in this system.

AIP Conference Proceedings, 2006

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2001

In this paper, we present results of a study on Sb doping in lead tungstate crystals. The crystal... more In this paper, we present results of a study on Sb doping in lead tungstate crystals. The crystal growth by modified Bridgman method is described. Result of trace analysis on raw materials and crystals is presented. The segregation coefficient of Sb ions in lead tungstate crystals was determined. The scintillation emission and longitudinal transmittance spectra, light output, decay kinetics and radiation damage were measured. It is found that Sb doping alone is not sufficient to produce radiation hard lead tungstate crystals, and post growth oxygen compensation is required.

2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC), 2009

In this paper, we report an investigation on the radiation damage effects induced by neutrons in ... more In this paper, we report an investigation on the radiation damage effects induced by neutrons in large size crystal scintillator: BGO, CeF¿, LYSO:Ce and PWO. The irradiations were carried out by using fast neutrons from one ¾ ½ Am-Be and two ¾ ¾ Cf sources. The optical and scintillation properties of these samples, including UV excitation and emission spectra, longitudinal transmission, light output, decay kinetics and light response uniformity, were measured before and after the irradiations. The neutron induced photo-current was also measured, and was used to estimate the readout noise under the neutron flux expected by an electromagnetic calorimeter at a very severe radiation environment. Because of its high light output and excellent radiation resistance LYSO:Ce crystal is found to have the smallest neutron induced readout noise as compared to other large size crystals, indicating it is a good candidate material for a future crystal calorimeter in a severe radiation environment.

2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC), 2009

An effort has been made to introduce scintillation light in lead fluoride crystals by selective d... more An effort has been made to introduce scintillation light in lead fluoride crystals by selective doping. It was found that some rare earth ions doped in the crystal may serve as luminescence centers. The photo-and X-luminescence spectrum, the decay time constant and the light output of these doped samples are presented. Because of the slow decay time these doped lead fluoride samples fall short to be used to build a homogeneous hadronic calorimeter with dual readout for future high energy physics experiments. Researches will continue to introduce scintillation in lead fluoride.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2002

Because of their high stopping power and fast scintillation, lead tungstate crystals have attract... more Because of their high stopping power and fast scintillation, lead tungstate crystals have attracted much attention in the high energy physics and nuclear physics communities. The use of lead tungstate, however, is limited by its low light output. An effort has been made at the Shanghai Institute of Ceramics to improve this. The results indicate that a factor of ten increase of the light output, mainly in the microsecond decay component, may be achieved. The photo luminescence spectrum, light output and decay kinetics of new samples are presented. Longitudinal uniformity of a sample of 22 radiation lengths is studied. Possible applications for calorimetry in high energy and nuclear physics experiments are discussed.

2006 IEEE Nuclear Science Symposium Conference Record, 2006

This paper presents a study on radiation damage effect in large size (2.5×2.5×20 cm 3) LSO and LY... more This paper presents a study on radiation damage effect in large size (2.5×2.5×20 cm 3) LSO and LYSO crystals. Optical and scintillation properties, including the longitudinal transmittance and emission spectra, the light output and light response uniformity with PMT and APD readout, are measured before and after γ-ray irradiations with integrated dosage up to 10 6 rad for three LSO and LYSO samples from different vendors. It was found that the recovery of radiation damage under room temperature is negligible, indicating that radiation damage in LSO and LYSO crystals are not dose rate dependent. It was also found that the overall radiation damage in LSO and LYSO crystals is small as compared to other crystal scintillators commonly used in high energy and nuclear physics experiments.

2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC), 2009

This paper compares-ray induced radiation damage effect in two kinds of heavy crystal scintillato... more This paper compares-ray induced radiation damage effect in two kinds of heavy crystal scintillators: PWO and LSO/LYSO. Scintillation emission, optical transmission, light output, decay kinetics and light response uniformity were measured for PWO and LSO/LYSO crystal samples of large size before and after-ray irradiations.-ray induced phosphorescence was also measured, and the corresponding readout noise was determined.

IEEE Transactions on Nuclear Science, 2001

IEEE Transactions on Nuclear Science, 2002

Because of its high density and superior quality factor, sapphire crystal, as a candidate materia... more Because of its high density and superior quality factor, sapphire crystal, as a candidate material for test masses, has attracted much attention in gravitation wave communities. The use of sapphire crystal, however, is limited by its size, homogeneity and absorption. An effort has been made at the Shanghai Institute of Optics and Fine Mechanics in a collaboration with the Laser Interferometer Gravitational Wave Observatory Laboratory to overcome these difficulties. By using Directional Temperature Gradient Technique (TGT), sapphire crystals of 11 cm in diameter and 8 cm in length were grown at the C plane (0001). The results indicate that a homogeneity of ¢ ¡ ¤ £ ¦ ¥ § © and an absorption of 35-65 ppm/cm have been achieved at wavelength of 1.06 m. This paper presents the TGT growth of sapphire crystals, their transmittance spectra, optical homogeneity and absorption. Future applications for gravitational wave experiments are discussed.

IEEE Transactions on Nuclear Science, 2000

This paper presents result of a study on undoped as well as various doped lead tungstate crystals... more This paper presents result of a study on undoped as well as various doped lead tungstate crystals. Radiation induced color center density was compared to radio luminescence. Light output degradation for crystals under irradiation was measured. Correlations between variations of crystal transmittance and light output were investigated. Monitoring wavelength was determined so that adequate sensitivity and good linearity may be achieved.

IEEE Transactions on Nuclear Science, 2007

This paper presents a study of the gamma-ray induced radiation damage effect in large size (2.5 2... more This paper presents a study of the gamma-ray induced radiation damage effect in large size (2.5 2.5 20 cm 3) LSO and LYSO crystal samples. Optical and scintillation properties, including longitudinal transmittance and photo-luminescence spectra, light output and light response uniformity with PMT and APD readout, are measured before and after-ray irradiations with an integrated dose up to 10 6 rad for three LSO and LYSO samples from different vendors. It was found that 300 C thermal annealing removes all radiation induced absorption. The photo-luminescence spectra measured before and after the irradiations were found to be consistent, indicating that the scintillation mechanism is not damaged. The radiation damage recovers very slow under the room temperature, indicating that the radiation damage level in LSO and LYSO crystals is not dose rate dependent. It was also found that the overall radiation damage in LSO and LYSO crystals is small as compared to other crystal scintillators commonly used in high energy and nuclear physics experiments.

IEEE Transactions on Nuclear Science, 2007

IEEE Transactions on Nuclear Science, 2005

Because of their high stopping power and fast bright scintillation, cerium doped silicate based h... more Because of their high stopping power and fast bright scintillation, cerium doped silicate based heavy crystal scintillators, such as GSO, LSO, and LYSO, have been developed for medical instruments. Their applications in high energy and nuclear physics, however, are limited by lacking high quality crystals in sufficiently large size. The optical and scintillation properties, including the transmittance, emission and excitation spectra and the light output, decay kinetics and light response uniformity, as well as their degradation under-ray irradiation were measured for two long (2.5 2.5 20 cm) LYSO samples from CPI and Saint-Gobain, and were compared to a BGO sample of the same size from SIC. Possible applications for crystal calorimetry in future high energy and nuclear physics experiments are discussed.

IEEE Transactions on Nuclear Science, 2005

IEEE Transactions on Nuclear Science, 2008

Light monitoring will play a crucial role in maintaining the energy resolution of the CMS lead tu... more Light monitoring will play a crucial role in maintaining the energy resolution of the CMS lead tungstate crystal electromagnetic calorimeter (ECAL) in situ at LHC. Since 2001, a laser based monitoring system has been used in the CMS ECAL beam tests at CERN. While the stability of the laser pulse energy and width, measured in 24 hours, is at a level of 3%, a long term degradation of both the laser pulse energy and the width were observed, as well as a drift of the laser pulse center timing at 2 ns/day. This degradation and drift, caused by the natural aging of the DC Kr lamp, would affect respectively the monitoring precision and the synchronization between the laser pulse and the ECAL ADC clock. This paper presents a design and implementation of a software feedback control which stabilizes the laser pulse energy, width and timing. With the software feedback implemented, a stability of the laser pulse energy and width at 3% level and a pulse timing jitter at 2 ns were observed in laser runs lasted for more than 3 months. The 0.5% energy resolution of the CMS PbWO 4 crystal ECAL is maintained after applying the laser monitoring corrections in a beam irradiation test.

IEEE Transactions on Nuclear Science, 2008

IEEE Transactions on Nuclear Science, 2010

An effort was made to introduce scintillation light in lead fluoride crystals by selective doping... more An effort was made to introduce scintillation light in lead fluoride crystals by selective doping. It was found that some rare earth ions doped in the lead fluoride crystal may serve as luminescence centers. The photo- and X- luminescence spectra, the decay time constants and the light outputs were measured for these doped samples. The decay time was found to be at a few milliseconds for these rare earth doped lead fluoride samples, which is too long to be useful for the homogeneous hadronic calorimeter detector concept with dual readout for future high energy physics experiments. Work to introduce scintillation in lead fluoride will continue.

IEEE Transactions on Nuclear Science, 2004

IEEE Transactions on Nuclear Science, 2011

Neutron induced nuclear counter effect in Hamamatsu silicon PIN diodes and APDs was measured by i... more Neutron induced nuclear counter effect in Hamamatsu silicon PIN diodes and APDs was measured by irradiating fast neutrons from a pair of252Cf sources directly to these devices. It was found that the entire kinetic energy of these neutrons may be converted into electron signals in these devices, leading to anomalous signals of up to a few million electrons in a single isolated calorimeter readout channel. Signals of such amplitude represent equivalent energy of several hundred GeV and a few GeV for PWO and LSO/LYSO crystals respectively assuming the corresponding light yields of 4 and 800 p.e./MeV. The overall rate of the neutron induced nuclear counter effect in APDs is found to be more than an order of magnitude less than that in PIN diodes. Increasing the APD gain was also found to reduce the neutron induced nuclear counter effect. An intelligent front-end chip capable of selecting un-contaminated signal is proposed to eliminate completely the nuclear counter effect without signif...

arXiv: Strongly Correlated Electrons, 2020

The phonon hydrodynamic system has only been detected experimentally in the limited compounds bec... more The phonon hydrodynamic system has only been detected experimentally in the limited compounds because of its stringent condition to appear. Herein, we elucidate the existence of hydrodynamic features driven by the collective excitation of Dirac fluid in semimetal ZrTe5. By measuring the electrical and the thermal property in a wide temperature range, we find the regime as satisfying phonon hydrodynamic-like characteristics with two representative experimental evidence: faster evolution of thermal conductivity than the ballistic regime and the existence of a local maximum of effective mean-free-path. Unlike the phononic hydrodynamics, a magnitude of hundreds violated Wiedemann-Franz law, and phonon-dragged anomalies can be seen, which provide us as a signature of the Dirac fluid in this system.

AIP Conference Proceedings, 2006

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2001

In this paper, we present results of a study on Sb doping in lead tungstate crystals. The crystal... more In this paper, we present results of a study on Sb doping in lead tungstate crystals. The crystal growth by modified Bridgman method is described. Result of trace analysis on raw materials and crystals is presented. The segregation coefficient of Sb ions in lead tungstate crystals was determined. The scintillation emission and longitudinal transmittance spectra, light output, decay kinetics and radiation damage were measured. It is found that Sb doping alone is not sufficient to produce radiation hard lead tungstate crystals, and post growth oxygen compensation is required.

2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC), 2009

In this paper, we report an investigation on the radiation damage effects induced by neutrons in ... more In this paper, we report an investigation on the radiation damage effects induced by neutrons in large size crystal scintillator: BGO, CeF¿, LYSO:Ce and PWO. The irradiations were carried out by using fast neutrons from one ¾ ½ Am-Be and two ¾ ¾ Cf sources. The optical and scintillation properties of these samples, including UV excitation and emission spectra, longitudinal transmission, light output, decay kinetics and light response uniformity, were measured before and after the irradiations. The neutron induced photo-current was also measured, and was used to estimate the readout noise under the neutron flux expected by an electromagnetic calorimeter at a very severe radiation environment. Because of its high light output and excellent radiation resistance LYSO:Ce crystal is found to have the smallest neutron induced readout noise as compared to other large size crystals, indicating it is a good candidate material for a future crystal calorimeter in a severe radiation environment.

2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC), 2009

An effort has been made to introduce scintillation light in lead fluoride crystals by selective d... more An effort has been made to introduce scintillation light in lead fluoride crystals by selective doping. It was found that some rare earth ions doped in the crystal may serve as luminescence centers. The photo-and X-luminescence spectrum, the decay time constant and the light output of these doped samples are presented. Because of the slow decay time these doped lead fluoride samples fall short to be used to build a homogeneous hadronic calorimeter with dual readout for future high energy physics experiments. Researches will continue to introduce scintillation in lead fluoride.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2002

Because of their high stopping power and fast scintillation, lead tungstate crystals have attract... more Because of their high stopping power and fast scintillation, lead tungstate crystals have attracted much attention in the high energy physics and nuclear physics communities. The use of lead tungstate, however, is limited by its low light output. An effort has been made at the Shanghai Institute of Ceramics to improve this. The results indicate that a factor of ten increase of the light output, mainly in the microsecond decay component, may be achieved. The photo luminescence spectrum, light output and decay kinetics of new samples are presented. Longitudinal uniformity of a sample of 22 radiation lengths is studied. Possible applications for calorimetry in high energy and nuclear physics experiments are discussed.

2006 IEEE Nuclear Science Symposium Conference Record, 2006

This paper presents a study on radiation damage effect in large size (2.5×2.5×20 cm 3) LSO and LY... more This paper presents a study on radiation damage effect in large size (2.5×2.5×20 cm 3) LSO and LYSO crystals. Optical and scintillation properties, including the longitudinal transmittance and emission spectra, the light output and light response uniformity with PMT and APD readout, are measured before and after γ-ray irradiations with integrated dosage up to 10 6 rad for three LSO and LYSO samples from different vendors. It was found that the recovery of radiation damage under room temperature is negligible, indicating that radiation damage in LSO and LYSO crystals are not dose rate dependent. It was also found that the overall radiation damage in LSO and LYSO crystals is small as compared to other crystal scintillators commonly used in high energy and nuclear physics experiments.

2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC), 2009

This paper compares-ray induced radiation damage effect in two kinds of heavy crystal scintillato... more This paper compares-ray induced radiation damage effect in two kinds of heavy crystal scintillators: PWO and LSO/LYSO. Scintillation emission, optical transmission, light output, decay kinetics and light response uniformity were measured for PWO and LSO/LYSO crystal samples of large size before and after-ray irradiations.-ray induced phosphorescence was also measured, and the corresponding readout noise was determined.

IEEE Transactions on Nuclear Science, 2001

IEEE Transactions on Nuclear Science, 2002

Because of its high density and superior quality factor, sapphire crystal, as a candidate materia... more Because of its high density and superior quality factor, sapphire crystal, as a candidate material for test masses, has attracted much attention in gravitation wave communities. The use of sapphire crystal, however, is limited by its size, homogeneity and absorption. An effort has been made at the Shanghai Institute of Optics and Fine Mechanics in a collaboration with the Laser Interferometer Gravitational Wave Observatory Laboratory to overcome these difficulties. By using Directional Temperature Gradient Technique (TGT), sapphire crystals of 11 cm in diameter and 8 cm in length were grown at the C plane (0001). The results indicate that a homogeneity of ¢ ¡ ¤ £ ¦ ¥ § © and an absorption of 35-65 ppm/cm have been achieved at wavelength of 1.06 m. This paper presents the TGT growth of sapphire crystals, their transmittance spectra, optical homogeneity and absorption. Future applications for gravitational wave experiments are discussed.

IEEE Transactions on Nuclear Science, 2000

This paper presents result of a study on undoped as well as various doped lead tungstate crystals... more This paper presents result of a study on undoped as well as various doped lead tungstate crystals. Radiation induced color center density was compared to radio luminescence. Light output degradation for crystals under irradiation was measured. Correlations between variations of crystal transmittance and light output were investigated. Monitoring wavelength was determined so that adequate sensitivity and good linearity may be achieved.

IEEE Transactions on Nuclear Science, 2007

This paper presents a study of the gamma-ray induced radiation damage effect in large size (2.5 2... more This paper presents a study of the gamma-ray induced radiation damage effect in large size (2.5 2.5 20 cm 3) LSO and LYSO crystal samples. Optical and scintillation properties, including longitudinal transmittance and photo-luminescence spectra, light output and light response uniformity with PMT and APD readout, are measured before and after-ray irradiations with an integrated dose up to 10 6 rad for three LSO and LYSO samples from different vendors. It was found that 300 C thermal annealing removes all radiation induced absorption. The photo-luminescence spectra measured before and after the irradiations were found to be consistent, indicating that the scintillation mechanism is not damaged. The radiation damage recovers very slow under the room temperature, indicating that the radiation damage level in LSO and LYSO crystals is not dose rate dependent. It was also found that the overall radiation damage in LSO and LYSO crystals is small as compared to other crystal scintillators commonly used in high energy and nuclear physics experiments.

IEEE Transactions on Nuclear Science, 2007

IEEE Transactions on Nuclear Science, 2005

Because of their high stopping power and fast bright scintillation, cerium doped silicate based h... more Because of their high stopping power and fast bright scintillation, cerium doped silicate based heavy crystal scintillators, such as GSO, LSO, and LYSO, have been developed for medical instruments. Their applications in high energy and nuclear physics, however, are limited by lacking high quality crystals in sufficiently large size. The optical and scintillation properties, including the transmittance, emission and excitation spectra and the light output, decay kinetics and light response uniformity, as well as their degradation under-ray irradiation were measured for two long (2.5 2.5 20 cm) LYSO samples from CPI and Saint-Gobain, and were compared to a BGO sample of the same size from SIC. Possible applications for crystal calorimetry in future high energy and nuclear physics experiments are discussed.

IEEE Transactions on Nuclear Science, 2005

IEEE Transactions on Nuclear Science, 2008

Light monitoring will play a crucial role in maintaining the energy resolution of the CMS lead tu... more Light monitoring will play a crucial role in maintaining the energy resolution of the CMS lead tungstate crystal electromagnetic calorimeter (ECAL) in situ at LHC. Since 2001, a laser based monitoring system has been used in the CMS ECAL beam tests at CERN. While the stability of the laser pulse energy and width, measured in 24 hours, is at a level of 3%, a long term degradation of both the laser pulse energy and the width were observed, as well as a drift of the laser pulse center timing at 2 ns/day. This degradation and drift, caused by the natural aging of the DC Kr lamp, would affect respectively the monitoring precision and the synchronization between the laser pulse and the ECAL ADC clock. This paper presents a design and implementation of a software feedback control which stabilizes the laser pulse energy, width and timing. With the software feedback implemented, a stability of the laser pulse energy and width at 3% level and a pulse timing jitter at 2 ns were observed in laser runs lasted for more than 3 months. The 0.5% energy resolution of the CMS PbWO 4 crystal ECAL is maintained after applying the laser monitoring corrections in a beam irradiation test.

IEEE Transactions on Nuclear Science, 2008

IEEE Transactions on Nuclear Science, 2010

An effort was made to introduce scintillation light in lead fluoride crystals by selective doping... more An effort was made to introduce scintillation light in lead fluoride crystals by selective doping. It was found that some rare earth ions doped in the lead fluoride crystal may serve as luminescence centers. The photo- and X- luminescence spectra, the decay time constants and the light outputs were measured for these doped samples. The decay time was found to be at a few milliseconds for these rare earth doped lead fluoride samples, which is too long to be useful for the homogeneous hadronic calorimeter detector concept with dual readout for future high energy physics experiments. Work to introduce scintillation in lead fluoride will continue.

IEEE Transactions on Nuclear Science, 2004

IEEE Transactions on Nuclear Science, 2011

Neutron induced nuclear counter effect in Hamamatsu silicon PIN diodes and APDs was measured by i... more Neutron induced nuclear counter effect in Hamamatsu silicon PIN diodes and APDs was measured by irradiating fast neutrons from a pair of252Cf sources directly to these devices. It was found that the entire kinetic energy of these neutrons may be converted into electron signals in these devices, leading to anomalous signals of up to a few million electrons in a single isolated calorimeter readout channel. Signals of such amplitude represent equivalent energy of several hundred GeV and a few GeV for PWO and LSO/LYSO crystals respectively assuming the corresponding light yields of 4 and 800 p.e./MeV. The overall rate of the neutron induced nuclear counter effect in APDs is found to be more than an order of magnitude less than that in PIN diodes. Increasing the APD gain was also found to reduce the neutron induced nuclear counter effect. An intelligent front-end chip capable of selecting un-contaminated signal is proposed to eliminate completely the nuclear counter effect without signif...