Study of Positronium in Insulating Crystals

绝缘晶体中正电子的研究

• 批准号: 08404018
• 负责人: HYODO Toshio
• 金额: $ 25.92万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08404018/
• 关键词: Positron annihilation; Positron; Positronium; 2D-ACAR; Insulator; Alkali halide; Quartz; Spin-crossover salt; 合成石英; 四重極相互作用; スピン偏極; 偏極率; 局在ポジトロニウム; トンネル効果; 陽電子ビーム; ライナック; 仕事関数; 2光子角相関; 拡散定数; スルカリハライド; スビンクロスオーバー錯塩; スピン転移; スピン交換; 非局在

A positron injected in insulating material form a hydrogen-like bound state with an electron called positronium. Behavior of ositronium in insulating materials has attracted interests in relation with the properties of excitions. It is also realized as a probe of the spin states of materials.The present study revealed various aspects of the positronium interactions with materials by using 2D-ACAR apparatus recently developed by us, the high intensity slow positron beam line at KEK, and conventional positron annihilation techniques including 1D-ACAR, positron lifetime ,Doppler broadening of annihilation radiation, positron age-momentum correlation.New results have been obtained for the following subjects :(1) Wave functions of delocalized positronium in alkali halides at low temperatures.(2) Effect of the phonon scattering on the momentum distribution of positronium in quartz and MgFィイD22ィエD2.(3) Tunneling transition of delocalized positronium to a self-localized state.(4) Positronium emission from quartz single crystal and fused silica.(5) Positronium lifetime in quartz single crystal.(6) Study of spin-crossover material and related material by using positronium.(7) Positronium quadrupole interactions in anistoropic crystals.(8) Development of positron spin polarimeter by using positronium in solids.

注入绝缘材料中的正电子与称为正电子素的电子形成类似氢的束缚态。锇在绝缘材料中的行为与激发态的性质有关，引起了人们的兴趣。本研究利用我们最近研制的2D-ACAR装置、KEK的高强度慢正电子束线和常规的正电子湮没技术，包括1D-ACAR、正电子寿命、湮没辐射的多普勒展宽、正电子年龄-动量关联，获得了以下几个问题的新结果：（1）低温下碱金属卤化物中离域正电子偶素的波函数。(2)声子散射对石英和MgF晶体中电子偶素动量分布的影响(3)离域电子偶素到自定域态的隧穿跃迁。(4)石英单晶和熔融石英的电子偶素发射。(5)石英单晶中的正电子素寿命。(6)利用正电子素研究自旋交叉材料及相关材料。(7)各向异性晶体中的电子偶素四极相互作用。(8)利用固体中的正电子素研制正电子自旋极化计。

项目成果

Y. Nagai: "Study of delocolized positronium in alkali halides by LD-ACAR"Mat. Sci. Forum. 255-257. 569-571 (1997)

Y. Nagai：“通过 LD-ACAR 对碱金属卤化物中脱位正电子素的研究”Mat。

Y. Nagai, Y. Nagashima, and Hyodo: "Lifetime of delocalized positronium in α-SiOィイD22ィエD2"Phys. Rev. B. 60. 7677-7679 (1999)

Y. Nagai、Y. Nagashima 和 Hyodo：“α-SiO D22 中离域正电子素的寿命”Phys Rev. B. 60. 7677-7679 (1999)

Y.Nagashima: "Origin of Positronium Emitted from SiO_2" Phys.Rev.B. 58. 12676-12679 (1998)

Y.Nagashima：“SiO_2 中发射的正电子的起源”Phys.Rev.B。

Y.Nagai: "Two-dimensional 2γ Angular Correlation Study of Delocalised Positromium in Alkal : Halides" journal of physics : Condensed matter. Vol.9. 11239-11246 (1997)

Y.Nagai：“碱中离域正原子的二维 2γ 角相关研究：卤化物”物理学杂志：凝聚态物质第 9 卷（1997 年）。

Y.Nagai: "Analysis of Momentum Distribution of Bloch-Positronium in Solids" Materials Science Forum. 255-257. 596-598 (1997)

Y.Nagai：“固体中布洛赫-正电子的动量分布分析”材料科学论坛。