共查询到16条相似文献,搜索用时 187 毫秒
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低温地面支持设备系统CGSE是用于冷却第二代阿尔法磁谱仪AMS02的磁体组件并将超流氦注入AMS02磁体杜瓦的低温设备系统。介绍用于CGSE系统中液位指示稳定的补液式低温沸腾换热器,介绍了换热器的技术特性、设计原理、结构特征和技术要求。该低温沸腾换热器的结构特征主要在于两个筒体的使用,其中加注液体及装液位计的稳定筒与沸腾的换热筒是分开的,通过封头连通,减小了沸腾引起的液位计信号波动。另外的一个结构特征是汇气管的使用,降低了气流对液位的冲击。最终实现了液位指示稳定,提高了低温沸腾换热器的换热性能,具有显著的经济效益和社会效益。 相似文献
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AMS02超导磁体的低温地面支持设备系统(CGSE)方案研究 总被引:2,自引:2,他引:0
AMS02是用于探测空间反物质、暗物质及宇宙射线的第二代阿尔法磁谱探测仪,它将利用航天飞机发射至国际空间站上,并以超导状态工作3年以上。AMS02的核心是一个大型超导磁体,重达2000kg,需要在发射前用一低温地面支持设备系统(CGSE)对磁体进行冷却并在磁体杜瓦中加注2.5m3的超流氦。该文介绍此CGSE的技术要求、总体方案、冷却过程和主要子系统。 相似文献
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国际空间站上的阿尔发磁谱仪(Alpha Magnetic Spectrometer AMS)是太空中第一个大型高能粒子探测器,用于探测反物质、暗物质和宇宙线。本刊2011年第5期曾有详细报道。AMS先后有2种型号:AMS01和AMS02。AMS01用永久磁铁,场强约0.15T,重3吨,早在1998年已在发现号航天飞机上成功试飞过。AMS02安置在国际空间站上,原计划采用超导磁铁,场强约0.87T, 相似文献
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国际空间站上的阿尔发磁谱仪(Alpha Magnetic SpectrometerAMS)是太空中第一个大型高能粒子探测器,用于探测反物质、暗物质和宇宙线。本刊2011年第5期曾有详细报道。AMS先后有2种型号:AMS01和AMS02。AMS01用永久磁铁,场强约0.15 T,重3吨,早在1998年已在发现号航天飞机上成功试飞过。AMS02安置在国际空间站上,原计划采用超导磁铁,场强约0.87 T,为此科学家们差不多花了近10年功夫,却在2010年离发射不到1年的时候决定放弃超导方案,仍用1998年已经试飞考验过的、场强较低的永磁方案。这到底是为什么呢? 相似文献
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AMS 实验
阿尔法磁谱仪(Alpha Magnetic Spectrometer,简称AMS)是国际空间站(International Space Station,简称ISS)上唯一的大型高能粒子探测器,也是人类送入太空的第一个大型磁谱仪。AMS 实验是丁肇中教授领导的大型国际合作项目,其科学目标是寻找宇宙中的反物质、暗物质及精确测量宇宙线的成分和能谱。参加AMS 实验的科学工作者来自三大洲(美洲、欧洲、亚洲)的16 个国家(地区),共有60 个大学或研究机构,600 多人。 相似文献
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The magnetic proton recoil(MPR)spectrometer is a novel diagnostic instrument with high perfor-mance for measurements of neutron spectra in inertial confinement fusion(ICF)experiments and high power fusion devices.A compact MPR-type spectrometer dedicated to the research of pulsed deuterium-tritium(DT)neutron spectroscopy of special experimental conditions is currently under design.Analyses of the main parameters and performance of the magnetic analysis system through 3-D particle transport calculations and MonteCarlo simulations and calibration of the system performance as a test using CR-39 solid track detector and α particle from 239pu and 226Ra radioactive sources are presented in this paper.The results indicate that the magnetic analysis system will achieve a detection efficiency level of 10-5-10-4 at an energy resolution of 1.5%-2.1%,and fulfills the design goals of the spectrometer. 相似文献
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V. V. Alekseev K. M. Belotsky Yu. V. Bogomolov R. I. Budaev A. M. Galper O. A. Dunaeva A. A. Kirillov A. V. Kuznetsov A. D. Lukyanov A. G. Mayorov M. A. Mayorova V. V. Malakhov A. F. Mosichkin A. A. Okrugin S. A. Rodenko A. M. Shitova 《Physics of Particles and Nuclei》2017,48(5):687-690
The paper provides a review of the results of precision measurements of the fluxes of different charged components of galactic cosmic rays (positrons and antiprotons, protons and helium nuclei) in modern experiments with magnetic spectrometers PAMELA and AMS-02, operating successfully for a few years (since 2006 and 2011, respectively) in Earth orbit. A priority of the PAMELA spectrometer scientific discoveries is noted. It is also noted that the measurements from the AMS-02 experiment are of high statistical accuracy and have reliably confirmed previous data, having been able to advance to a higher energy range. 相似文献
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A very high-momentum resolution particle spectrometer called the Alpha Magnetic Spectrometer (AMS) was flown in the payload bay of the Space Shuttle in a 51.65 degrees x 380-km orbit during the last solar minimum. This spectrometer has provided the first high statistics data set for galactic cosmic radiation protons, and helium, as well as limited spectral data on carbon and oxygen nuclei in the International Space Station orbit. First measurements of the albedo protons at this inclination were also made. Because of the high-momentum resolution and high statistics, the data can be separated as a function of magnetic latitude. A related investigation, the balloon borne experiment with a superconducting solenoid spectrometer (BESS), has been flown from Lynn Lake, Canada and has also provided excellent high-resolution data on protons and helium. These two data sets have been used here to study the validity of two galactic cosmic ray models and the geomagnetic transmission function developed from the 1990 geomagnetic reference field model. The predictions of both the CREME96 and NASA/JSC models are in good agreement with the AMS data. The shape of the AMS measured albedo proton spectrum, up to 2 GeV, is in excellent agreement with the previous balloon and satellite observations. A new LIS spectrum was developed that is consistent with both previous and new BESS 3He observations. Because the astronaut radiation exposures onboard ISS will be highest around the time of the solar minimum, these AMS measurements and these models provide important benchmarks for future radiation studies. AMS-02 slated for launch in September 2003, will provide even better momentum resolution and higher statistics data. 相似文献
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Cervical spine MR imaging using multislice gradient echo imaging: comparison with cardiac gated spin echo 总被引:2,自引:0,他引:2
M V Kulkarni P A Narayana C B McArdle J W Yeakley N F Campagna F W Wehrli 《Magnetic resonance imaging》1988,6(5):517-525
Forty-one patients with suspected cervical spine disorders were studied using multislice gradient echo imaging (GE) technique, with a 1.5-T system. The images were compared to cardiac-gated spin echo (CGSE) images in the diagnosis of suspected cord and spinal disorders. Images were graded for ability to detect cord lesion, cord-CSF contrast, CSF-bone contrast and contrast between CSF and extradural abnormality. The signal-to-noise ratio and contrast-to-noise ratio were used to compare images. There was 44% decrease in contrast between cord lesion and normal cord on GE when compared to CGSE, except for spinal cord hemorrhage. There was a 40% improvement between bone and CSF contrast on GE compared to CGSE. GE images were significantly better qualitatively as well as quantitatively in the detection of extradural lesions. This effect was more marked in axial plane where CGSE images are extremely suboptimal. CGSE images are better than GE for spinal cord lesions, while GE are superior in the diagnosis of degenerative disease in the cervical spine. 相似文献
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