Alpha particle radiation detectors with planar double Schottky contacts(DSC)are directly fabricated on 5-μm-thick epitaxial semi-insulating(SI)GaN:Fe film with resistivity higher than 1×10^(8)Ω·cm.Under 10...Alpha particle radiation detectors with planar double Schottky contacts(DSC)are directly fabricated on 5-μm-thick epitaxial semi-insulating(SI)GaN:Fe film with resistivity higher than 1×10^(8)Ω·cm.Under 10 V bias,the detector exhibits a low dark current of less than 5.0×10^(-11) A at room-temperature,which increases at higher temperatures.Linear behavior in the semi-log reverse current-voltage plot suggests that Poole-Frenkel emission is the dominant carrier leakage mechanism at high bias.Distinct double-peak characteristics are observed in the energy spectrum of alpha particles regardless of bias voltage.The energy resolution of the SI-GaN based detector is determined to be8.6%at the deposited energy of 1.209 MeV with a charge collection efficiency of81.7%.At a higher temperature of 90℃,the measured full width at half maximum(FWHM)rises to 235 keV with no shift of energy peak position,which proves that the GaN detector has potential to work stably in high temperature environment.This study provides a possible route to fabricate the low cost GaN-based alpha particle detector with reasonable performance.展开更多
The aim of this paper is to determine the maximum values of the track length (Lmax) of alpha particles in Nuclear Track Detector (type CR-39) using a new method by taking the relation between the etching time and the ...The aim of this paper is to determine the maximum values of the track length (Lmax) of alpha particles in Nuclear Track Detector (type CR-39) using a new method by taking the relation between the etching time and the diameter square of alpha particle with different energies at constant bulk etch rate VB (1.45 μm/hr) by using TRACK_TEST program from Brun et al. function and Yu et al. function. Using the new equation, the maximum values of the track lengths of alpha particles measured in CR-39 detector have been found to be in a good agreement with the values measured by using Brun et al. function and Yu et al. function in TRACK_TEST program.展开更多
Au/Ni/n-type 4H-SiC Schottky alpha particle detectors are fabricated and annealed at temperatures between 400℃ and 700 ℃ to investigate the effects of thermal stability of the Schottky contact on the structural and ...Au/Ni/n-type 4H-SiC Schottky alpha particle detectors are fabricated and annealed at temperatures between 400℃ and 700 ℃ to investigate the effects of thermal stability of the Schottky contact on the structural and electrical properties of the detectors. At the annealing temperature of 500 ℃, the two nickel silicides （i.e., Ni31Sil2 and Ni2Si） are formed at the interface and result in the formation of an inhomogeneous Schottky barrier. By increasing the annealing temperature, the Ni31Sil2 transforms into the more stable Ni2Si. The structural evolution of the Schottky contact directly affects the electrical properties and alpha particle energy resolutions of the detectors. A better energy resolution of 2.60% is obtained for 5.48-MeV alpha particles with the detector after being annealed at 600 ℃. As a result, the Au/Ni/n-type 4H-SiC Schottky detector shows a good performance after thermal treatment at temperatures up to 700℃.展开更多
In cases of high radiation emergencies,we propose a surface contamination monitor(SCM)that can quickly measure and pinpoint the contamination distribution in the affected population.Thick gaseous electron multiplier(T...In cases of high radiation emergencies,we propose a surface contamination monitor(SCM)that can quickly measure and pinpoint the contamination distribution in the affected population.Thick gaseous electron multiplier(THGEM)has several advantages,including fast response time and good spatial resolution.Based on new THGEMs,a two-dimensional imaging detector was developed for alpha detection,with a position resolution greater than 3 mm.The detector design and test results are described in this paper.Fast radiation imaging SCMs,with a 40mm×40 mm sensitive area,are currently under development.展开更多
A sealed high gas pressure detector working in pure argon is assembled.It consists of a 5 cm × 5 cm PCB THGEM（THick Gaseous Electron Multiplier）.The detector structure and experimental setup are described.The p...A sealed high gas pressure detector working in pure argon is assembled.It consists of a 5 cm × 5 cm PCB THGEM（THick Gaseous Electron Multiplier）.The detector structure and experimental setup are described.The performance under high pressure（2 atm） is examined,selecting optimal voltages for the ionization region and induction region.The dependence of the shape of alpha particle spectra measured with relative gas gain on gas pressure（1.3-2.0 atm） has been studied.Eight data sets of relative gas gain versus working voltage of THGEM,expressed by weighting field E/P,are normalized,consistent with theory.The results show that the air tightness of the chamber is good,measured by a sensitive barometer and checked with gas gain.The experimental results are compared with Monte Carlo simulation of energy deposition without gas gain involved.展开更多
基金Project supported by the Natural Science Foundation of Jiangsu Province,China(Grant Nos.BK20190302 and BK20201253).
文摘Alpha particle radiation detectors with planar double Schottky contacts(DSC)are directly fabricated on 5-μm-thick epitaxial semi-insulating(SI)GaN:Fe film with resistivity higher than 1×10^(8)Ω·cm.Under 10 V bias,the detector exhibits a low dark current of less than 5.0×10^(-11) A at room-temperature,which increases at higher temperatures.Linear behavior in the semi-log reverse current-voltage plot suggests that Poole-Frenkel emission is the dominant carrier leakage mechanism at high bias.Distinct double-peak characteristics are observed in the energy spectrum of alpha particles regardless of bias voltage.The energy resolution of the SI-GaN based detector is determined to be8.6%at the deposited energy of 1.209 MeV with a charge collection efficiency of81.7%.At a higher temperature of 90℃,the measured full width at half maximum(FWHM)rises to 235 keV with no shift of energy peak position,which proves that the GaN detector has potential to work stably in high temperature environment.This study provides a possible route to fabricate the low cost GaN-based alpha particle detector with reasonable performance.
文摘The aim of this paper is to determine the maximum values of the track length (Lmax) of alpha particles in Nuclear Track Detector (type CR-39) using a new method by taking the relation between the etching time and the diameter square of alpha particle with different energies at constant bulk etch rate VB (1.45 μm/hr) by using TRACK_TEST program from Brun et al. function and Yu et al. function. Using the new equation, the maximum values of the track lengths of alpha particles measured in CR-39 detector have been found to be in a good agreement with the values measured by using Brun et al. function and Yu et al. function in TRACK_TEST program.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11675198,61574026,and 11405017)the National Key Research and Development Program of China(Grant Nos.2016YFB0400600 and 2016YFB0400601)+1 种基金the Natural Science Foundation of Liaoning Province of China(Grant Nos.201602453 and 201602176)the China Postdoctoral Science Foundation(Grant No.2016M591434)
文摘Au/Ni/n-type 4H-SiC Schottky alpha particle detectors are fabricated and annealed at temperatures between 400℃ and 700 ℃ to investigate the effects of thermal stability of the Schottky contact on the structural and electrical properties of the detectors. At the annealing temperature of 500 ℃, the two nickel silicides （i.e., Ni31Sil2 and Ni2Si） are formed at the interface and result in the formation of an inhomogeneous Schottky barrier. By increasing the annealing temperature, the Ni31Sil2 transforms into the more stable Ni2Si. The structural evolution of the Schottky contact directly affects the electrical properties and alpha particle energy resolutions of the detectors. A better energy resolution of 2.60% is obtained for 5.48-MeV alpha particles with the detector after being annealed at 600 ℃. As a result, the Au/Ni/n-type 4H-SiC Schottky detector shows a good performance after thermal treatment at temperatures up to 700℃.
基金supported by the China Institute of Atomic Energy and University of Chinese Academy of SciencesNational Natural Science Foundation of China(Nos.11575193 and U1732266)+2 种基金Key Research Program of Frontier Sciences,CAS(No.QYZDB-SSWSLH039)the Youth Innovation Promotion Association of CAS(No.2016153)the Natural Science Key Foundation of Guangxi(No.2015GXNSFDA139002)
文摘In cases of high radiation emergencies,we propose a surface contamination monitor(SCM)that can quickly measure and pinpoint the contamination distribution in the affected population.Thick gaseous electron multiplier(THGEM)has several advantages,including fast response time and good spatial resolution.Based on new THGEMs,a two-dimensional imaging detector was developed for alpha detection,with a position resolution greater than 3 mm.The detector design and test results are described in this paper.Fast radiation imaging SCMs,with a 40mm×40 mm sensitive area,are currently under development.
基金Supported by National Natural Science Foundation of China(11575193,11205240,11265003,U1431109)
文摘A sealed high gas pressure detector working in pure argon is assembled.It consists of a 5 cm × 5 cm PCB THGEM（THick Gaseous Electron Multiplier）.The detector structure and experimental setup are described.The performance under high pressure（2 atm） is examined,selecting optimal voltages for the ionization region and induction region.The dependence of the shape of alpha particle spectra measured with relative gas gain on gas pressure（1.3-2.0 atm） has been studied.Eight data sets of relative gas gain versus working voltage of THGEM,expressed by weighting field E/P,are normalized,consistent with theory.The results show that the air tightness of the chamber is good,measured by a sensitive barometer and checked with gas gain.The experimental results are compared with Monte Carlo simulation of energy deposition without gas gain involved.
