| 1. |
- Zhang, S. N., et al.
(författare)
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The high energy cosmic-radiation detection (HERD) facility onboard China's Space Station
- 2014
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 9780819496126
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Konferensbidrag (refereegranskat)abstract
- The High Energy cosmic-Radiation Detection (HERD) facility is one of several space astronomy payloads of the cosmic lighthouse program onboard China's Space Station, which is planned for operation starting around 2020 for about 10 years. The main scientific objectives of HERD are indirect dark matter search, precise cosmic ray spectrum and composition measurements up to the knee energy, and high energy gamma-ray monitoring and survey. HERD is composed of a 3-D cubic calorimeter (CALO) surrounded by microstrip silicon trackers (STKs) from five sides except the bottom. CALO is made of about 104 cubes of LYSO crystals, corresponding to about 55 radiation lengths and 3 nuclear interaction lengths, respectively. The top STK microstrips of seven X-Y layers are sandwiched with tungsten converters to make precise directional measurements of incoming electrons and gamma-rays. In the baseline design, each of the four side SKTs is made of only three layers microstrips. All STKs will also be used for measuring the charge and incoming directions of cosmic rays, as well as identifying back scattered tracks. With this design, HERD can achieve the following performance: energy resolution of 1% for electrons and gamma-rays beyond 100 GeV, 20% for protons from 100 GeV to 1 PeV; electron/proton separation power better than 10-5; effective geometrical factors of >3 m2sr for electron and diffuse gamma-rays, >2 m2sr for cosmic ray nuclei. R and D is under way for reading out the LYSO signals with optical fiber coupled to image intensified CCD and the prototype of one layer of CALO.
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| 2. |
- Sitek, J., et al.
(författare)
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Comparisons of nano-additives influence on properties of the bi-modal solder pastes for special applications
- 2011
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Ingår i: Proceedings - 12th International Conference on Electronic Packaging Technology and High Density Packaging, ICEPT-HDP 2011, Shanghai, 8-11 August 2011. - 9781457717680 ; , s. 183-187
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Konferensbidrag (refereegranskat)abstract
- The paper presented the results of investigation of two solder pastes SnBi and SAC with different nano-particles, which could be applied for special application. It was presented that materials and samples preparation for investigation. The results of SEM analyzer of solder joints executed using these pastes and their shear strength measurements enable to make the comparison of nano-additives influence on properties of the bi-modal solders pastes. It was observed that addition of nano-particles into both solder pastes changed the microstructure of solder joints, and formed a large number of nano-sized grains with uniform distribution. For the SAC solder joints with nano-Ag particles it was also observed that specific Ag3Sn crystallites. We supposed that the Ag3Sn crystals, which created "internal net" and nano-sized grains with uniform distribution must influence the mechanical properties of the solder joints. The results of shear strength measurements of solder joints confirmed the significantly higher shear strength of bimodal solder joints in comparison to reference solder joints without nano-additives.
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