EAPSI: Variable Energy Positron Beam for Positronium Diffraction

EAPSI：用于正电子衍射的可变能量正电子束

• 批准号: 1515174
• 负责人: Randall Gladen
• 金额: $ 0.51万
• 依托单位: Gladen Randall W
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-15 至 2016-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1515174&HistoricalAwards=false
• 关键词: EAPSI; Variable; Energy; Positron; Beam

This award supports participation of a U.S. graduate student in a cutting edge experiment using the new positronium beam developed by Professor Yasuyuki Nagashima of Tokyo University of Science (TUS). The Nagashima beam consists of positronium particles, which will be diffracted from solid surfaces. In the experiment, positronium particles will be diffracted from solid surfaces, providing a unique neutral-particle spectroscopic method with several advantages over conventional neutral-particle spectroscopy, including particle size and the reduction in damage of the surface of the sample. This experiment will also provide the first observation of the diffraction of positronium from solid surfaces, providing valuable experimental evidence for theoretical quantum mechanics, as well as experimental results that will aid in the development of other spectroscopic methods. Future experiments may include the study of porous and catalytic materials for the development of fuel cells and the production of hydrogen from water using solar energy. This work will also contribute to the collaboration between the Nagashima laboratory at TUS and the Positron Surface Laboratory group at the University of Texas at Arlington (UTA).Professor Yasuyuki Nagashima and his research group, in collaboration with the High Energy Accelerator Research Organization (KEK), successfully constructed an earlier positronium beam using the photo-detachment of electrons from negative positronium ions, with a new positronium beam currently under construction. Using this unique method, this energy-tunable beam surpassed the previous beam energy limit of 400 eV, with measured minimum and maximum energies of 300 eV and 1.9 keV, respectively, and higher energies possible. The new beam?s properties of high flux, better collimation, and lower energy spread will enable the observation of multiple diffraction beams and the measurement of the energy dependence of the diffraction. Using this new positronium beam, which is expected to be completed by spring 2015, experiments consisting of the observation of high-energy positronium diffraction from solid surfaces, namely Si and LiF, will be performed. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.

该奖项支持一名美国研究生参与使用东京理科大学（TUS）教授Yasuyuki Nagashima开发的新正电子素束的尖端实验。Nagashima束由正电子素粒子组成，这些粒子将从固体表面衍射。在实验中，正电子素粒子将从固体表面衍射，提供了一种独特的中性粒子光谱法，与传统的中性粒子光谱法相比具有几个优点，包括粒子大小和减少样品表面的损伤。该实验还将首次观察到正电子素从固体表面的衍射，为理论量子力学提供有价值的实验证据，以及有助于其他光谱方法发展的实验结果。未来的实验可能包括研究多孔和催化材料，用于开发燃料电池和利用太阳能从水中生产氢。这项工作也将有助于TUS的Nagashima实验室与德克萨斯大学阿灵顿分校（UTA）的正电子表面实验室小组之间的合作。Nagashima教授及其研究小组与高能加速器研究组织（KEK）合作，成功地利用负正电子素离子的电子光分离构建了早期的正电子素束，一个新的正电子素束正在建设中。使用这种独特的方法，这种能量可调光束超过了以前的光束能量限制400 eV，测量的最小和最大能量分别为300 eV和1.9 keV，以及更高的能量可能。新的平衡木？的高通量，更好的准直性，和较低的能量扩展的属性将使多个衍射光束的观察和衍射的能量依赖性的测量。使用这种新的正电子素束，预计将在2015年春季完成，实验包括观察固体表面，即Si和LiF的高能正电子素衍射。这个NSF EAPSI奖是与日本科学促进协会合作资助的。