Over the past few years,phonon detectors have emerged as a prevailing technology for detecting lowmass dark matter due to their low thresholds and high resolution.These detectors,which employ either dual-phase detecto...Over the past few years,phonon detectors have emerged as a prevailing technology for detecting lowmass dark matter due to their low thresholds and high resolution.These detectors,which employ either dual-phase detectors combining phonon-light or phonon-electron interactions,have significantly advanced direct dark matter detection efforts.Argon,as a low-background and high-reserve detection medium,has also played a crucial role in this field.Both liquid-argon single-phase detectors and gas-liquid two-phase time projection chambers(TPCs)have contributed substantially to the direct detection of high-mass dark matter.By integrating these distinct detector types,the upper limits of the corresponding mass cross-section in dark matter detection can be lowered.We propose a phonon detector utilizing solid argon as the absorber,which combines the advantages of both aforementioned detector types.However,due to the requirement for an ultra-low temperature environment in the tens of millikelvin(mK)range,experimental investigations of solid argon phonon detector performance are currently constrained by technical limitations.Therefore,the performance analysis of the solid argon phonon detector presented in this study is only based on sapphire phonon detectors.Although there may be discrepancies between this approximation and the actual performance,the intrinsic characteristics of phonon detectors permit a qualitative evaluation of the solid argon phonon detector's potential capabilities.展开更多
为严格控制铝合金焊丝内在氢含量,分析了铝合金焊丝冶炼过程中充氩工艺参数对合金熔体及固体氢含量的影响,并比较了熔体测氢与固体测氢方法的异同。结果表明,2~4吨铝熔体冶炼过程中,减小精炼氩气的流量可以显著减少合金熔体减压凝固测...为严格控制铝合金焊丝内在氢含量,分析了铝合金焊丝冶炼过程中充氩工艺参数对合金熔体及固体氢含量的影响,并比较了熔体测氢与固体测氢方法的异同。结果表明,2~4吨铝熔体冶炼过程中,减小精炼氩气的流量可以显著减少合金熔体减压凝固测氢试样纵切面上的气孔数量和尺寸,降低熔体的氢含量,当充氩流量为8~10 mL/min时,熔体除氢效果达到最佳;固体测氢方法可以准确提取固体焊丝中的真实氢含量(单位:ppm),经过计算1 mL/100 g Al等价于0.899 ppm,当氩气流量控制在8~10 mL/min时固体焊丝合金中的氢含量为0.17~0.18 mL/100 g Al,可满足低氢焊丝生产要求;同等充氩工艺条件下,固体测氢值高于熔体测氢值,二者比值保持在1.7~2.1之间,固体测氢与熔体测氢各有优劣,二者可以互为补充、配合使用。展开更多
基金the National Key Research and Development Program of China(2017YFA0402203)the National Natural Science Foundation of China(12075161)。
文摘Over the past few years,phonon detectors have emerged as a prevailing technology for detecting lowmass dark matter due to their low thresholds and high resolution.These detectors,which employ either dual-phase detectors combining phonon-light or phonon-electron interactions,have significantly advanced direct dark matter detection efforts.Argon,as a low-background and high-reserve detection medium,has also played a crucial role in this field.Both liquid-argon single-phase detectors and gas-liquid two-phase time projection chambers(TPCs)have contributed substantially to the direct detection of high-mass dark matter.By integrating these distinct detector types,the upper limits of the corresponding mass cross-section in dark matter detection can be lowered.We propose a phonon detector utilizing solid argon as the absorber,which combines the advantages of both aforementioned detector types.However,due to the requirement for an ultra-low temperature environment in the tens of millikelvin(mK)range,experimental investigations of solid argon phonon detector performance are currently constrained by technical limitations.Therefore,the performance analysis of the solid argon phonon detector presented in this study is only based on sapphire phonon detectors.Although there may be discrepancies between this approximation and the actual performance,the intrinsic characteristics of phonon detectors permit a qualitative evaluation of the solid argon phonon detector's potential capabilities.
文摘为严格控制铝合金焊丝内在氢含量,分析了铝合金焊丝冶炼过程中充氩工艺参数对合金熔体及固体氢含量的影响,并比较了熔体测氢与固体测氢方法的异同。结果表明,2~4吨铝熔体冶炼过程中,减小精炼氩气的流量可以显著减少合金熔体减压凝固测氢试样纵切面上的气孔数量和尺寸,降低熔体的氢含量,当充氩流量为8~10 mL/min时,熔体除氢效果达到最佳;固体测氢方法可以准确提取固体焊丝中的真实氢含量(单位:ppm),经过计算1 mL/100 g Al等价于0.899 ppm,当氩气流量控制在8~10 mL/min时固体焊丝合金中的氢含量为0.17~0.18 mL/100 g Al,可满足低氢焊丝生产要求;同等充氩工艺条件下,固体测氢值高于熔体测氢值,二者比值保持在1.7~2.1之间,固体测氢与熔体测氢各有优劣,二者可以互为补充、配合使用。
