Purpose This study aimed to optimize the pre-treatment process for electroless nickel-phosphorus plating in the Einstein Probe project,addressing technical challenges encountered with 6061 aluminum alloy substrates to...Purpose This study aimed to optimize the pre-treatment process for electroless nickel-phosphorus plating in the Einstein Probe project,addressing technical challenges encountered with 6061 aluminum alloy substrates to enhance coating quality and operational efficiency.Methods Verification experiments were conducted using 6061 aluminum alloy sheets as substitutes for large aluminum mandrels.The effects of surface roughness,rinsing methods,and the necessity of acid pickling were systematically evaluated.The samples were characterized by scanning electron microscopy,atomic force microscopy,and energy-dispersive X-ray spectroscopy to analyze surface morphology and elemental composition.Results and Conclusion Excessive surface roughness should be avoided,with a roughness below 338 nm ensuring uniform coatings.Flowing water rinsing after each step was critical to prevent contamination from residual solutions,whereas stagnant water immersion proved inadequate.Acid pickling was determined to be non-essential,as it had minimal impact on coating quality.The zinc layer formed during immersion exhibited weak adhesion and should be rinsed gently to avoid detachment.These findings offer valuable insights for pre-treatment process refinement in the Einstein Probe project and related applications.展开更多
Background:The Einstein Probe mission is an astronomical satellite developed in China,focusing on time-domain astronomy in the soft X-ray energy band.A key payload of this mission is the follow-up X-ray telescope(FXT)...Background:The Einstein Probe mission is an astronomical satellite developed in China,focusing on time-domain astronomy in the soft X-ray energy band.A key payload of this mission is the follow-up X-ray telescope(FXT),which is the result of international collaboration between China and Europe.The FXT features gold-coated nickel Wolter-I-type focusing mirrors and utilizes PNCCD detectors for imaging and spectroscopy in the focal plane.Methods:We reviewed the seven-year development history of the FXT.Initially,the configuration of the FXT consisted of a single telescope unit in 2017,but it later evolved into a dual-unit setup.Building on the successful design of eROSITA,the FXT team has innovatively introduced new operational modes for the PNCCD.FXT team also developed an ultra-compact helium pulse tube refrigerator,which cools the PNCCD down to-90℃.Additionally,various passive shielding measures have been implemented to protect against high-energy charged particles and enhance radiation resistance.These advancements have significantly improved the overall performance and reliability of the FXT.Results and conclusion:The ground calibrations and tests of the FXT demonstrate that its primary performance meets the established design goals.The FXT has exhibited outstanding performance in orbit,establishing itself as one of the space X-ray telescopes with considerable international influence.展开更多
Purpose The Einstein Probe(EP)satellite is a science mission of the Chinese Academy of Sciences,which is dedicated to time-domain astronomy and high-energy astrophysics.The X-ray baffle is a crucial component of follo...Purpose The Einstein Probe(EP)satellite is a science mission of the Chinese Academy of Sciences,which is dedicated to time-domain astronomy and high-energy astrophysics.The X-ray baffle is a crucial component of follow-up X-ray telescope(FXT),which is an important payload onboard EP.It was designed to efficiently reduce stray light,especially single reflection on the hyperboloid of Wolter-I Mirrors.Methods In this paper,based on the parameters of FXT's mirror module and the detector,the design parameters of the X-ray baffle are optimized through preliminary design and detailed ray-tracing simulation.Fabrication involved precision laser cutting,roll forming,laser welding and integration processes.The thermal stability and mechanical environment adaptability were validated through thermal cycling and mechanical vibration tests.Finally,the X-ray baffle was mounted onto the mirror module with alignment precisely controlled using optical methods.Results The height of the X-ray baffle ranges from 60 to 120 mm from the outside to the inside;the aperture corresponds to each layer of the mirror module.In order to reduce weight and reduce light occlusion,the thickness of each thin shell is 0.125 mm.The ray-tracing simulation results with X-ray baffle are shown that the stray light is effectively reduced in the effective region of the detector.The Eigen-frequency change of the X-ray baffle after the thermal cycle test and mechanical vibration tests is only 0.52%and 0.77%,respectively.The results proved that X-ray baffle has a high thermo-mechanical reliability.The half power diameter(HPD)of the mirror module remained unchanged on-axis with/without X-ray baffle.Conclusion The introduction of X-ray baffle is expected to be highly significantly reduce stray light.展开更多
Purpose The purpose of the study was to prepare and evaluate the performance of graphite/copper composites in accelerators.Methods A series of graphite/copper composites were prepared by powder metallurgy.Based on the...Purpose The purpose of the study was to prepare and evaluate the performance of graphite/copper composites in accelerators.Methods A series of graphite/copper composites were prepared by powder metallurgy.Based on the relative density,bending strength,thermal conductivity,linear expansion coefficient,steady-state stability normalized index(SSNI),and electrical conductivity,the ratio of graphite/copper in the composites was optimized.Results The type of graphite greatly influenced the properties of the resulting graphite/copper composites.Compared with flake graphite/copper,spherical graphite/copper had a higher bending strength,thermal conductivity coefficient,SSNI,and conductivity.Although the dopant did not react with graphite,it greatly impacted the properties of the graphite/copper composite.Increasing the graphite content after doping with Ti and Ni resulted in a higher thermal conductivity and SSNI compared with the undoped or mono-doped composites.The graphite content greatly influenced the thermal conductivity of the composite.When the graphite content did not exceed 40 vol%,the thermal conductivity of the graphite/copper composite changed only slightly with the temperature.When the graphite content exceeded 45 vol%,the thermal conductivity of the graphite/copper composite decreased with temperature.Conclusion Among the prepared graphite/copper composites,titanium/nickel/spherical graphite/copper with a spherical graphite content of 50 vol%had the largest SSNI,which was higher than that of copper.Under specific conditions,it may be used as a substitute for copper in collimators or beam dumps.Different graphite/copper composites showed different coefficients of linear expansion,with a reasonable allocation of graphite and dopants.These composites may be used as transition layers in the brazing connection of large graphite and copper-based materials.展开更多
Introduction This article contributes to time coincidence gamma-ray spectroscopy in nuclear physics with HPGe detectors.The proposed concept of the measurement apparatus is aimed at studying various effects,including ...Introduction This article contributes to time coincidence gamma-ray spectroscopy in nuclear physics with HPGe detectors.The proposed concept of the measurement apparatus is aimed at studying various effects,including Compton scattering,cascade gamma emissions,backscattering between detectors,Doppler broadening,and X-ray escape measurements.Objectives The coincidence measurements have a significant impact on the observations of these effects,which cannot be explored through single-channel measurements alone.The primary objective is to identify and study these effects.Results The reactions are experimentally acquired with Na-22,Co-60,Cs-137,and Eu-152 isotopes and via a long-term exposition measuring the natural background.The confirmation of these reactions is demonstrated with the use of selected visualization methods.The measurements conducted to determine the timing conditions,related to the charge collection time,are also presented.Conclusions The main novelty of this contribution is the measurement of X-ray escape peaks.The X-ray is generated within the germanium.When it escapes from the detector,it can be captured by the second detector and summed with the photopeak energy.We use the Na-22 source,which simultaneously produces two gamma-rays.The X-ray is subtracted from the photopeak in one detector and added to the full photopeak in another,as shown in the energy spectra.The coincidence condition,along with the selected energy window,is applied to enhance measurements of the X-ray escape peaks.展开更多
The Einstein Probe(EP)is a space X-ray astronomical mission led by Chinese Academy of Sciences(CAS)in collaboration with Europe.It was successfully launched into a low-Earth orbit with an altitude of 580 km and an inc...The Einstein Probe(EP)is a space X-ray astronomical mission led by Chinese Academy of Sciences(CAS)in collaboration with Europe.It was successfully launched into a low-Earth orbit with an altitude of 580 km and an inclination of 29 degrees on January 9,2024.Its primary objectives are to discover and characterize X-ray transients in the universe,observe outbursts from dormant black holes,and search for X-ray counterparts of gravitational wave events.展开更多
1.Aims and scope.Radiation Detection Technology and Methods(RDTM)focuses on all aspects of radiation detection technology and methods,including electronics and system design,computer and control techniques,detection t...1.Aims and scope.Radiation Detection Technology and Methods(RDTM)focuses on all aspects of radiation detection technology and methods,including electronics and system design,computer and control techniques,detection technology and methods,data processing and imaging.It presents an attractive mix of authoritative and comprehensive reviews,original articles on cutting-edge research and brief communications.The journal offers rapid review and publication of articles.展开更多
1.Aims and scope.Radiation Detection Technology and Methods(RDTM)focuses on all aspects of radiation detection technology and methods,including electronics and system design,computer and control techniques,detection t...1.Aims and scope.Radiation Detection Technology and Methods(RDTM)focuses on all aspects of radiation detection technology and methods,including electronics and system design,computer and control techniques,detection technology and methods,data processing and imaging.It presents an attractive mix of authoritative and comprehensive reviews,original articles on cutting-edge research and brief communications.The journal offers rapid review and publication of articles.展开更多
1.Aimsand scope.Radiation Detection Technology and Methods(RDTM)focuses on all aspects of radiation detection technology and methods,including electronics and system design,computer and control techniques,detection te...1.Aimsand scope.Radiation Detection Technology and Methods(RDTM)focuses on all aspects of radiation detection technology and methods,including electronics and system design,computer and control techniques,detection technology and methods,data processing and imaging.It presents an attractive mix of authoritative and comprehensive reviews,original articles on cutting-edge research and brief communications.The journal offers rapid review and publication of articles.展开更多
The Einstein Probe(EP)satellite represents a significant milestone in China's pursuit of advancing time-domain astronomy and high-energy astrophysics.At its core lies the Follow-up X-ray Telescope(FXT),a groundbre...The Einstein Probe(EP)satellite represents a significant milestone in China's pursuit of advancing time-domain astronomy and high-energy astrophysics.At its core lies the Follow-up X-ray Telescope(FXT),a groundbreaking payload that marks China's first foray into Wolter-I focusing technology for X-ray imaging.Designed with a dual-telescope structure,FXT incorporates 54 layers of ultra-smooth,gold-coated nickel mirror shells nested within each focusing mirror,paired with an advanced PNCCD focal plane detector,coupled with an advanced PNCCD focal plane detector.展开更多
This study presents a mathematical model for the peak efficiency of a coaxial high-purity germanium detector using the Monte Carlo code(MCNP),based on data provided by the manufacturer.Consequently,the detector’s mod...This study presents a mathematical model for the peak efficiency of a coaxial high-purity germanium detector using the Monte Carlo code(MCNP),based on data provided by the manufacturer.Consequently,the detector’s model is optimized using a trial-and-error methodology,either by increasing/decreasing the dead layer thickness,aligning the peak efficiency results with experimental measurements.Results indicate that,over 15 years of continuous operation,the dead layer is approximately twice as thick as initially quoted by the manufacturer.Therefore,the dead layer results would confirm that it is crucial to regularly optimize the dead layer over time,as the operator needs to address potential occasional changes.The results indicate that the optimized MC model is suitable for calculating the activity of point/volumetric radioactive sources,with relative errors of 4.40 and 3.23%,respectively.Moreover,this work discusses the different factors that affect the accuracy of the absolute efficiency calibration of gamma spectrometers.展开更多
Correction to:Radiation Detection Technology and Methods(2024)8:1486-1495.https://doi.org/10.1007/s41605-024-00470-z.In this article Methods section of the publication,the term(beamline scientific data acquisition sys...Correction to:Radiation Detection Technology and Methods(2024)8:1486-1495.https://doi.org/10.1007/s41605-024-00470-z.In this article Methods section of the publication,the term(beamline scientific data acquisition system)is incorrectly written and redundant,it has been removed.展开更多
Purpose The follow-up X-ray telescope(FXT)is one of the two payloads of the Einstein Probe(EP),consisting of the upper composite with the X-ray mirror module as the core,the lower composite with the pnCCD module as th...Purpose The follow-up X-ray telescope(FXT)is one of the two payloads of the Einstein Probe(EP),consisting of the upper composite with the X-ray mirror module as the core,the lower composite with the pnCCD module as the core,and the interface structure.The FXT thermal control subsystem is responsible for the thermal design,thermal implementations,and testing of the entire FXT payload thermal control.Methods A design approach is adopted with passive thermal control technology as the main method and active thermal control technology as a supplement for common components.The X-ray mirror modules are high-precision optical components,utilizing active closed-loop temperature control to ensure high precision and stability.The pnCCD detectors operate at a stable low temperature,with refrigerators used to cool the detector houses,ensuring they can operate under stable low-temperature conditions.The hot ends of the refrigerators are connected to the external radiator panels through heat pipes for heat dissipation.Results The thermal control subsystem of FXT is operating properly in-orbit.All component temperatures meet the design requirements.Conclusion After multiple rounds of design and test verification,FXT was successfully launched with EP and completed in-orbit testing.During the in-orbit testing phase of EP,the function of the FXT thermal control subsystem works well.The temperatures of the components and units are normal.This paper introduces the design of FXT thermal control and the in-orbit performance of the thermal control subsystem.展开更多
Purpose The China initiative Accelerator Driven System(CiADS)consists of a superconducting proton linac system,a spallation target system and a sub-critical reactor system.In recent several decades,many control techno...Purpose The China initiative Accelerator Driven System(CiADS)consists of a superconducting proton linac system,a spallation target system and a sub-critical reactor system.In recent several decades,many control technologies have been developed for each of these individual systems—accelerators,targets and reactors.These valuable technologies can be used in the control system for the CiADS facility;however,practical applications still require addressing challenges related to operational logic and communication interfaces.Furthermore,in order to effectively couple and integrate the different systems of accelerator,target and reactor into a complete facility,it is essential to explore and develop new methods and technologies.Methods The proposed control architecture has been formulated with consideration for both the specific demands and characteristics of the CiADS and the principles of universal control system architectures.Then,the core issues related to system coupling are identified,followed by the design of logical functions,testing of communication interfaces,and verification of system integration.The key verification has been conducted on the prototype of the CiADS control system,focusing on the communication and hardware integration between the Experimental Physics and Industrial Control System(EPICS)and the Distributed Control System(DCS)of reactor,as well as the reactor power control function.After the design and development of the beam power stability strategy,it was experimentally verified on the China Accelerator Facility for superheavy Elements(CAFE2).Results and conclusion The prototype of the control system for CiADS has been established,successfully validating the interaction and communication capabilities between DCS and EPICS.Based on the proposed architecture,the implementation of the CiADS control system has been building step-by-step.To ensure the autonomy of each system’s operation,the structures and functions of the accelerator,the target and the reactor have been designed in isolation,implementing both physical and logical separations.Finally,several key control technologies for integrating the accelerators,the target and the reactor into the complete facility are developed and validated.展开更多
Purpose China Spallation Neutron Source Ⅱ(CSNS-Ⅱ)plans to upgrade its linear accelerator to increase the beam energy from 80 to 300 MeV.The upgrade will utilize 324 MHz double-spoke superconducting cavities and 648 ...Purpose China Spallation Neutron Source Ⅱ(CSNS-Ⅱ)plans to upgrade its linear accelerator to increase the beam energy from 80 to 300 MeV.The upgrade will utilize 324 MHz double-spoke superconducting cavities and 648 MHz elliptical superconducting cavities.In order to minimize and shorten the future commissioning duration of the superconducting cavities with beam functionality,the management department of CSNS-Ⅱ has decided to conduct validation of superconducting cavity beam tuning software and methods at the Chinese Accelerator Driven Sub-critical System(C-ADS)Injector I facility.As an experimental device,the C-ADS Injector I facility has been shut down for almost six years.To restore the operation of this machine,it is essential to effectively improve and upgrade the original control system of C-ADS Injector I facility.Methods To ensure high availability and reliability for the reactivation of the C-ADS Injector I facility,both the hardware and software of the original control system have been improved and enhanced.For example,the global timing was upgraded from continuous mode to pulsed mode,providing the operational sequence for the ECR(electron cyclotron resonance),chopper,RFQ(radio frequency quadrupole),and beam instruments.The beam interlock system,which includes MPS and FPS,has been redesigned to ensure the safe operation of all equipment,particularly the critical accelerator components.Proxmox VE was selected as the virtualization software to implement the private cloud platform.Results and conclusion Throughout the improvements and optimizations to the control system,it is evident that the availability and reliability of the control system have been substantially and effectively enhanced,which is crucial for the successful validation of the beam tuning methods and software for CSNS-Ⅱ superconducting cavity at the C-ADS injector I facility.展开更多
The Einstein Probe(EP)mission,approved by the Chinese Academy of Sciences(CAS)in 2017 and launched in 2024,is a significant advancement in time-domain astronomy.The Follow-up X-ray Telescope(FXT),equipped with a Wolte...The Einstein Probe(EP)mission,approved by the Chinese Academy of Sciences(CAS)in 2017 and launched in 2024,is a significant advancement in time-domain astronomy.The Follow-up X-ray Telescope(FXT),equipped with a Wolter I focusing mirror system and a PNCCD detector,is critical for detecting and analyzing cosmic X-rays.To ensure its reliability in space,structural and structural-thermal models were developed,and mechanical and thermal tests were conducted to verify its ability to withstand launch stresses and space conditions.The Wolter I mirrors,manufactured and integrated by the HIT team,achieved an angular resolution of 57 arcseconds at 1.5 keV and an effective area of 250 cm^(2).This paper presents the verification results of these tests,including insights from the flight spare model,and discusses potential reasons for the observed loss of effective area,such as alignment imperfections or thermal distortions.These findings are essential for optimizing the FXT’s design and ensuring the mission’s success,highlighting the importance of rigorous testing in space-based observatory development.展开更多
PandaX-4T is a xenon-based multi-purpose experiment,focusing on particle and astrophysics research.The data quality monitoring system plays a crucial role in the experiment.This system enables the prompt detection of ...PandaX-4T is a xenon-based multi-purpose experiment,focusing on particle and astrophysics research.The data quality monitoring system plays a crucial role in the experiment.This system enables the prompt detection of potential issues during data collection.In order to meet the upgrade requirements of the experiment,we have implemented several updates to improve overall data throughput and provide users with more comprehensive information.As a result,the system is capable of monitoring half of the collected data in future operations of the PandaX-4T experiment.Furthermore,with updated hardware,the system is also well equipped to meet the requirements of the future multi-ten-tonne-level PandaX-xT experiment.展开更多
Background Optical fiber radioluminescence measurement(OFRLM)is a cutting-edge technique poised to play a major role in radiation detection and dosimetry.Time-resolved measurement involves capturing the temporal dynam...Background Optical fiber radioluminescence measurement(OFRLM)is a cutting-edge technique poised to play a major role in radiation detection and dosimetry.Time-resolved measurement involves capturing the temporal dynamics of light emission from scintillators,providing detailed information about radiation pulses.Objective This review aims to evaluate various scintillator materials used in time-resolved OFRLM systems and their critical importance in capturing ionizing radiation pulses.Content The article discusses the properties of scintillator materials,including organic,inorganic,and composite compositions,and highlights their unique properties and suitability for time-resolved measurements with OFRLM systems.Performance characteristics,advantages,and limitations of different scintillator materials are thoroughly reviewed.Conclusion This review provides insights into the optimal selection of scintillator materials for time-resolved OFRLM systems,offering criteria for improving their performance and facilitating advancements in radiation detection and dosimetry.展开更多
Purpose This study is part of the Balqarad system's commissioning project.Optimizing the radioactivity detection and measurement using the Balqarad setup is highly important to investigate and explain the self-ind...Purpose This study is part of the Balqarad system's commissioning project.Optimizing the radioactivity detection and measurement using the Balqarad setup is highly important to investigate and explain the self-induced and ambient backgrounds to determine the actual sample-related features in the spectra acquired.Methods Balqarad is a radiation detection system composed of a clover,a variety of scintillators,lead shielding,and the standard electronics needed for the construction of gamma spectra.Four distinct setup configurations were set up to measure background radiation using a tailored analysis code.Results Background radiation from Balqarad components was assessed using two-dimensional background spectra features(hotspots and lines).Background sources in the system’s proximity were studied using one-dimensional spectra in both direct(single)and addback modes.Furthermore,these spectra were crucial in detecting and investigating any potential ^(207)Bi contamination of the bismuth germanium oxide(BGO)material.The results show that the decay from ^(211+211m)Po to the energy levels of ^(207m)Pb was measured,and this could be incorrectly interpreted as the decay of ^(207)Bi.Another noteworthy finding is the presence of a 59.5 keV peak,which was a significant contribution from the shielding to the detector’s background.This study also confirmed the detection of the cosmic peak of ^(74*)Ge generated by the(n,γ)reaction at 596.5 keV in the Ge-BGO system.Conclusion The technique was applied for Balqarad setup components in different configurations for background measurement.The study applied a coincidence/anticoincidence technique to the various configurations,resulting in a reduced cosmic background and the Compton continuum by a factor of 53%.展开更多
Introduction The 2 K laminated-finned heat exchanger(Lf-HX)enhances the efficiency of 2 K superfluid helium production,a pivotal equipment in the cryogenic system of the China Initiative Accelerator Driven System(CiAD...Introduction The 2 K laminated-finned heat exchanger(Lf-HX)enhances the efficiency of 2 K superfluid helium production,a pivotal equipment in the cryogenic system of the China Initiative Accelerator Driven System(CiADS).Materials and Methods This study utilizes computational fluid dynamics(CFD)simulations and experimental methods to investigate the impact of environmental heat leaks,ranging from 0 to 15 W,and flow rates from 1 to 5 g/s on the Lf-HX’s performance.Conclusion The results show that the heat exchanger’s effectiveness declines with increased flow rates under low heat leakage conditions,but this trend inverts under higher heat leakage scenarios.CFD and experimental data reveal that the axial heat leakage of the Lf-HX is 10 W/m2,and higher heat leakage reduces Lf-HX’s robustness.This study provides valuable data for the design and optimization of similar 2 K heat exchangers.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42327802 and 22479035).
文摘Purpose This study aimed to optimize the pre-treatment process for electroless nickel-phosphorus plating in the Einstein Probe project,addressing technical challenges encountered with 6061 aluminum alloy substrates to enhance coating quality and operational efficiency.Methods Verification experiments were conducted using 6061 aluminum alloy sheets as substitutes for large aluminum mandrels.The effects of surface roughness,rinsing methods,and the necessity of acid pickling were systematically evaluated.The samples were characterized by scanning electron microscopy,atomic force microscopy,and energy-dispersive X-ray spectroscopy to analyze surface morphology and elemental composition.Results and Conclusion Excessive surface roughness should be avoided,with a roughness below 338 nm ensuring uniform coatings.Flowing water rinsing after each step was critical to prevent contamination from residual solutions,whereas stagnant water immersion proved inadequate.Acid pickling was determined to be non-essential,as it had minimal impact on coating quality.The zinc layer formed during immersion exhibited weak adhesion and should be rinsed gently to avoid detachment.These findings offer valuable insights for pre-treatment process refinement in the Einstein Probe project and related applications.
基金supported by the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences(Grant No.XDA 15310103).
文摘Background:The Einstein Probe mission is an astronomical satellite developed in China,focusing on time-domain astronomy in the soft X-ray energy band.A key payload of this mission is the follow-up X-ray telescope(FXT),which is the result of international collaboration between China and Europe.The FXT features gold-coated nickel Wolter-I-type focusing mirrors and utilizes PNCCD detectors for imaging and spectroscopy in the focal plane.Methods:We reviewed the seven-year development history of the FXT.Initially,the configuration of the FXT consisted of a single telescope unit in 2017,but it later evolved into a dual-unit setup.Building on the successful design of eROSITA,the FXT team has innovatively introduced new operational modes for the PNCCD.FXT team also developed an ultra-compact helium pulse tube refrigerator,which cools the PNCCD down to-90℃.Additionally,various passive shielding measures have been implemented to protect against high-energy charged particles and enhance radiation resistance.These advancements have significantly improved the overall performance and reliability of the FXT.Results and conclusion:The ground calibrations and tests of the FXT demonstrate that its primary performance meets the established design goals.The FXT has exhibited outstanding performance in orbit,establishing itself as one of the space X-ray telescopes with considerable international influence.
基金supported by the Natural Science Basic Research Program of Shaanxi Province(2024JC-YBMS-532)the Natural Science Basic Research Program of Shaanxi Province(2023-JC-ZD-40)+1 种基金the Natural Science Basic Research Program of Shaanxi Province(2024JC-YBQN-0003)the Natural Science Basic Research Program of Shaanxi Province(2024JC-YBQN-0686).
文摘Purpose The Einstein Probe(EP)satellite is a science mission of the Chinese Academy of Sciences,which is dedicated to time-domain astronomy and high-energy astrophysics.The X-ray baffle is a crucial component of follow-up X-ray telescope(FXT),which is an important payload onboard EP.It was designed to efficiently reduce stray light,especially single reflection on the hyperboloid of Wolter-I Mirrors.Methods In this paper,based on the parameters of FXT's mirror module and the detector,the design parameters of the X-ray baffle are optimized through preliminary design and detailed ray-tracing simulation.Fabrication involved precision laser cutting,roll forming,laser welding and integration processes.The thermal stability and mechanical environment adaptability were validated through thermal cycling and mechanical vibration tests.Finally,the X-ray baffle was mounted onto the mirror module with alignment precisely controlled using optical methods.Results The height of the X-ray baffle ranges from 60 to 120 mm from the outside to the inside;the aperture corresponds to each layer of the mirror module.In order to reduce weight and reduce light occlusion,the thickness of each thin shell is 0.125 mm.The ray-tracing simulation results with X-ray baffle are shown that the stray light is effectively reduced in the effective region of the detector.The Eigen-frequency change of the X-ray baffle after the thermal cycle test and mechanical vibration tests is only 0.52%and 0.77%,respectively.The results proved that X-ray baffle has a high thermo-mechanical reliability.The half power diameter(HPD)of the mirror module remained unchanged on-axis with/without X-ray baffle.Conclusion The introduction of X-ray baffle is expected to be highly significantly reduce stray light.
基金supported by the National Natural Science Foundation of China(grant Nos.12105296,and 12105308)the Guangdong Provincial Key Laboratory of Extreme Conditions(2023B1212010002).
文摘Purpose The purpose of the study was to prepare and evaluate the performance of graphite/copper composites in accelerators.Methods A series of graphite/copper composites were prepared by powder metallurgy.Based on the relative density,bending strength,thermal conductivity,linear expansion coefficient,steady-state stability normalized index(SSNI),and electrical conductivity,the ratio of graphite/copper in the composites was optimized.Results The type of graphite greatly influenced the properties of the resulting graphite/copper composites.Compared with flake graphite/copper,spherical graphite/copper had a higher bending strength,thermal conductivity coefficient,SSNI,and conductivity.Although the dopant did not react with graphite,it greatly impacted the properties of the graphite/copper composite.Increasing the graphite content after doping with Ti and Ni resulted in a higher thermal conductivity and SSNI compared with the undoped or mono-doped composites.The graphite content greatly influenced the thermal conductivity of the composite.When the graphite content did not exceed 40 vol%,the thermal conductivity of the graphite/copper composite changed only slightly with the temperature.When the graphite content exceeded 45 vol%,the thermal conductivity of the graphite/copper composite decreased with temperature.Conclusion Among the prepared graphite/copper composites,titanium/nickel/spherical graphite/copper with a spherical graphite content of 50 vol%had the largest SSNI,which was higher than that of copper.Under specific conditions,it may be used as a substitute for copper in collimators or beam dumps.Different graphite/copper composites showed different coefficients of linear expansion,with a reasonable allocation of graphite and dopants.These composites may be used as transition layers in the brazing connection of large graphite and copper-based materials.
基金supported by the institutions participating in the CzechELib Transformative Agreement.
文摘Introduction This article contributes to time coincidence gamma-ray spectroscopy in nuclear physics with HPGe detectors.The proposed concept of the measurement apparatus is aimed at studying various effects,including Compton scattering,cascade gamma emissions,backscattering between detectors,Doppler broadening,and X-ray escape measurements.Objectives The coincidence measurements have a significant impact on the observations of these effects,which cannot be explored through single-channel measurements alone.The primary objective is to identify and study these effects.Results The reactions are experimentally acquired with Na-22,Co-60,Cs-137,and Eu-152 isotopes and via a long-term exposition measuring the natural background.The confirmation of these reactions is demonstrated with the use of selected visualization methods.The measurements conducted to determine the timing conditions,related to the charge collection time,are also presented.Conclusions The main novelty of this contribution is the measurement of X-ray escape peaks.The X-ray is generated within the germanium.When it escapes from the detector,it can be captured by the second detector and summed with the photopeak energy.We use the Na-22 source,which simultaneously produces two gamma-rays.The X-ray is subtracted from the photopeak in one detector and added to the full photopeak in another,as shown in the energy spectra.The coincidence condition,along with the selected energy window,is applied to enhance measurements of the X-ray escape peaks.
文摘The Einstein Probe(EP)is a space X-ray astronomical mission led by Chinese Academy of Sciences(CAS)in collaboration with Europe.It was successfully launched into a low-Earth orbit with an altitude of 580 km and an inclination of 29 degrees on January 9,2024.Its primary objectives are to discover and characterize X-ray transients in the universe,observe outbursts from dormant black holes,and search for X-ray counterparts of gravitational wave events.
文摘1.Aims and scope.Radiation Detection Technology and Methods(RDTM)focuses on all aspects of radiation detection technology and methods,including electronics and system design,computer and control techniques,detection technology and methods,data processing and imaging.It presents an attractive mix of authoritative and comprehensive reviews,original articles on cutting-edge research and brief communications.The journal offers rapid review and publication of articles.
文摘1.Aims and scope.Radiation Detection Technology and Methods(RDTM)focuses on all aspects of radiation detection technology and methods,including electronics and system design,computer and control techniques,detection technology and methods,data processing and imaging.It presents an attractive mix of authoritative and comprehensive reviews,original articles on cutting-edge research and brief communications.The journal offers rapid review and publication of articles.
文摘1.Aimsand scope.Radiation Detection Technology and Methods(RDTM)focuses on all aspects of radiation detection technology and methods,including electronics and system design,computer and control techniques,detection technology and methods,data processing and imaging.It presents an attractive mix of authoritative and comprehensive reviews,original articles on cutting-edge research and brief communications.The journal offers rapid review and publication of articles.
文摘The Einstein Probe(EP)satellite represents a significant milestone in China's pursuit of advancing time-domain astronomy and high-energy astrophysics.At its core lies the Follow-up X-ray Telescope(FXT),a groundbreaking payload that marks China's first foray into Wolter-I focusing technology for X-ray imaging.Designed with a dual-telescope structure,FXT incorporates 54 layers of ultra-smooth,gold-coated nickel mirror shells nested within each focusing mirror,paired with an advanced PNCCD focal plane detector,coupled with an advanced PNCCD focal plane detector.
文摘This study presents a mathematical model for the peak efficiency of a coaxial high-purity germanium detector using the Monte Carlo code(MCNP),based on data provided by the manufacturer.Consequently,the detector’s model is optimized using a trial-and-error methodology,either by increasing/decreasing the dead layer thickness,aligning the peak efficiency results with experimental measurements.Results indicate that,over 15 years of continuous operation,the dead layer is approximately twice as thick as initially quoted by the manufacturer.Therefore,the dead layer results would confirm that it is crucial to regularly optimize the dead layer over time,as the operator needs to address potential occasional changes.The results indicate that the optimized MC model is suitable for calculating the activity of point/volumetric radioactive sources,with relative errors of 4.40 and 3.23%,respectively.Moreover,this work discusses the different factors that affect the accuracy of the absolute efficiency calibration of gamma spectrometers.
文摘Correction to:Radiation Detection Technology and Methods(2024)8:1486-1495.https://doi.org/10.1007/s41605-024-00470-z.In this article Methods section of the publication,the term(beamline scientific data acquisition system)is incorrectly written and redundant,it has been removed.
基金supported by the Einstein-Probe(EP)Program which is funded by the Strategic Priority Research Program of the Chinese Academy of Sciences Grant No.XDA15310103.
文摘Purpose The follow-up X-ray telescope(FXT)is one of the two payloads of the Einstein Probe(EP),consisting of the upper composite with the X-ray mirror module as the core,the lower composite with the pnCCD module as the core,and the interface structure.The FXT thermal control subsystem is responsible for the thermal design,thermal implementations,and testing of the entire FXT payload thermal control.Methods A design approach is adopted with passive thermal control technology as the main method and active thermal control technology as a supplement for common components.The X-ray mirror modules are high-precision optical components,utilizing active closed-loop temperature control to ensure high precision and stability.The pnCCD detectors operate at a stable low temperature,with refrigerators used to cool the detector houses,ensuring they can operate under stable low-temperature conditions.The hot ends of the refrigerators are connected to the external radiator panels through heat pipes for heat dissipation.Results The thermal control subsystem of FXT is operating properly in-orbit.All component temperatures meet the design requirements.Conclusion After multiple rounds of design and test verification,FXT was successfully launched with EP and completed in-orbit testing.During the in-orbit testing phase of EP,the function of the FXT thermal control subsystem works well.The temperatures of the components and units are normal.This paper introduces the design of FXT thermal control and the in-orbit performance of the thermal control subsystem.
基金supported by the Large Research Infrastructures China initiative Accelerator Driven System(Grant No.2017-000052-75-01-000590)National Key Research and Development Project(No.2023YFA1606802).
文摘Purpose The China initiative Accelerator Driven System(CiADS)consists of a superconducting proton linac system,a spallation target system and a sub-critical reactor system.In recent several decades,many control technologies have been developed for each of these individual systems—accelerators,targets and reactors.These valuable technologies can be used in the control system for the CiADS facility;however,practical applications still require addressing challenges related to operational logic and communication interfaces.Furthermore,in order to effectively couple and integrate the different systems of accelerator,target and reactor into a complete facility,it is essential to explore and develop new methods and technologies.Methods The proposed control architecture has been formulated with consideration for both the specific demands and characteristics of the CiADS and the principles of universal control system architectures.Then,the core issues related to system coupling are identified,followed by the design of logical functions,testing of communication interfaces,and verification of system integration.The key verification has been conducted on the prototype of the CiADS control system,focusing on the communication and hardware integration between the Experimental Physics and Industrial Control System(EPICS)and the Distributed Control System(DCS)of reactor,as well as the reactor power control function.After the design and development of the beam power stability strategy,it was experimentally verified on the China Accelerator Facility for superheavy Elements(CAFE2).Results and conclusion The prototype of the control system for CiADS has been established,successfully validating the interaction and communication capabilities between DCS and EPICS.Based on the proposed architecture,the implementation of the CiADS control system has been building step-by-step.To ensure the autonomy of each system’s operation,the structures and functions of the accelerator,the target and the reactor have been designed in isolation,implementing both physical and logical separations.Finally,several key control technologies for integrating the accelerators,the target and the reactor into the complete facility are developed and validated.
基金Funding was provided by the Guangdong Basic and Applied Basic Research Foundation(2021B1515120021)by the Key Laboratory of Particle Acceleration Physics and Technology of the Chinese Academy of Sciences.
文摘Purpose China Spallation Neutron Source Ⅱ(CSNS-Ⅱ)plans to upgrade its linear accelerator to increase the beam energy from 80 to 300 MeV.The upgrade will utilize 324 MHz double-spoke superconducting cavities and 648 MHz elliptical superconducting cavities.In order to minimize and shorten the future commissioning duration of the superconducting cavities with beam functionality,the management department of CSNS-Ⅱ has decided to conduct validation of superconducting cavity beam tuning software and methods at the Chinese Accelerator Driven Sub-critical System(C-ADS)Injector I facility.As an experimental device,the C-ADS Injector I facility has been shut down for almost six years.To restore the operation of this machine,it is essential to effectively improve and upgrade the original control system of C-ADS Injector I facility.Methods To ensure high availability and reliability for the reactivation of the C-ADS Injector I facility,both the hardware and software of the original control system have been improved and enhanced.For example,the global timing was upgraded from continuous mode to pulsed mode,providing the operational sequence for the ECR(electron cyclotron resonance),chopper,RFQ(radio frequency quadrupole),and beam instruments.The beam interlock system,which includes MPS and FPS,has been redesigned to ensure the safe operation of all equipment,particularly the critical accelerator components.Proxmox VE was selected as the virtualization software to implement the private cloud platform.Results and conclusion Throughout the improvements and optimizations to the control system,it is evident that the availability and reliability of the control system have been substantially and effectively enhanced,which is crucial for the successful validation of the beam tuning methods and software for CSNS-Ⅱ superconducting cavity at the C-ADS injector I facility.
基金supported by the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences,Grant No.XDA1531010301.
文摘The Einstein Probe(EP)mission,approved by the Chinese Academy of Sciences(CAS)in 2017 and launched in 2024,is a significant advancement in time-domain astronomy.The Follow-up X-ray Telescope(FXT),equipped with a Wolter I focusing mirror system and a PNCCD detector,is critical for detecting and analyzing cosmic X-rays.To ensure its reliability in space,structural and structural-thermal models were developed,and mechanical and thermal tests were conducted to verify its ability to withstand launch stresses and space conditions.The Wolter I mirrors,manufactured and integrated by the HIT team,achieved an angular resolution of 57 arcseconds at 1.5 keV and an effective area of 250 cm^(2).This paper presents the verification results of these tests,including insights from the flight spare model,and discusses potential reasons for the observed loss of effective area,such as alignment imperfections or thermal distortions.These findings are essential for optimizing the FXT’s design and ensuring the mission’s success,highlighting the importance of rigorous testing in space-based observatory development.
基金supported by the grants from National Natural Science Foundation of China(No.12175139).
文摘PandaX-4T is a xenon-based multi-purpose experiment,focusing on particle and astrophysics research.The data quality monitoring system plays a crucial role in the experiment.This system enables the prompt detection of potential issues during data collection.In order to meet the upgrade requirements of the experiment,we have implemented several updates to improve overall data throughput and provide users with more comprehensive information.As a result,the system is capable of monitoring half of the collected data in future operations of the PandaX-4T experiment.Furthermore,with updated hardware,the system is also well equipped to meet the requirements of the future multi-ten-tonne-level PandaX-xT experiment.
基金TM R&D(grant number RDTC/241145)for their support of this research.
文摘Background Optical fiber radioluminescence measurement(OFRLM)is a cutting-edge technique poised to play a major role in radiation detection and dosimetry.Time-resolved measurement involves capturing the temporal dynamics of light emission from scintillators,providing detailed information about radiation pulses.Objective This review aims to evaluate various scintillator materials used in time-resolved OFRLM systems and their critical importance in capturing ionizing radiation pulses.Content The article discusses the properties of scintillator materials,including organic,inorganic,and composite compositions,and highlights their unique properties and suitability for time-resolved measurements with OFRLM systems.Performance characteristics,advantages,and limitations of different scintillator materials are thoroughly reviewed.Conclusion This review provides insights into the optimal selection of scintillator materials for time-resolved OFRLM systems,offering criteria for improving their performance and facilitating advancements in radiation detection and dosimetry.
文摘Purpose This study is part of the Balqarad system's commissioning project.Optimizing the radioactivity detection and measurement using the Balqarad setup is highly important to investigate and explain the self-induced and ambient backgrounds to determine the actual sample-related features in the spectra acquired.Methods Balqarad is a radiation detection system composed of a clover,a variety of scintillators,lead shielding,and the standard electronics needed for the construction of gamma spectra.Four distinct setup configurations were set up to measure background radiation using a tailored analysis code.Results Background radiation from Balqarad components was assessed using two-dimensional background spectra features(hotspots and lines).Background sources in the system’s proximity were studied using one-dimensional spectra in both direct(single)and addback modes.Furthermore,these spectra were crucial in detecting and investigating any potential ^(207)Bi contamination of the bismuth germanium oxide(BGO)material.The results show that the decay from ^(211+211m)Po to the energy levels of ^(207m)Pb was measured,and this could be incorrectly interpreted as the decay of ^(207)Bi.Another noteworthy finding is the presence of a 59.5 keV peak,which was a significant contribution from the shielding to the detector’s background.This study also confirmed the detection of the cosmic peak of ^(74*)Ge generated by the(n,γ)reaction at 596.5 keV in the Ge-BGO system.Conclusion The technique was applied for Balqarad setup components in different configurations for background measurement.The study applied a coincidence/anticoincidence technique to the various configurations,resulting in a reduced cosmic background and the Compton continuum by a factor of 53%.
基金financially supported by the Strategically leading scientific and technological project of the Chinese Academy of Sciences(No:E12G821Y)the Large Research Infrastructures China initiative Accelerator Driven System(No:2017-000052-75-01-000590).
文摘Introduction The 2 K laminated-finned heat exchanger(Lf-HX)enhances the efficiency of 2 K superfluid helium production,a pivotal equipment in the cryogenic system of the China Initiative Accelerator Driven System(CiADS).Materials and Methods This study utilizes computational fluid dynamics(CFD)simulations and experimental methods to investigate the impact of environmental heat leaks,ranging from 0 to 15 W,and flow rates from 1 to 5 g/s on the Lf-HX’s performance.Conclusion The results show that the heat exchanger’s effectiveness declines with increased flow rates under low heat leakage conditions,but this trend inverts under higher heat leakage scenarios.CFD and experimental data reveal that the axial heat leakage of the Lf-HX is 10 W/m2,and higher heat leakage reduces Lf-HX’s robustness.This study provides valuable data for the design and optimization of similar 2 K heat exchangers.
