发表机构
Nagoya University; Kobe University; Okayama University of Science（名古屋大学; 神户大学; 冈山理科大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
GRAINE 2023 项目研发了轻量化压力容器 gondola，完成 2.5 平方米乳胶伽马射线望远镜的首次夜间气球飞行，为未来大面积望远镜重复观测奠定技术基础。
AI 中文摘要
核乳胶伽马射线成像仪（GRAINE）项目利用搭载于气球上的高角分辨率核乳胶望远镜，对亚GeV至GeV能段的宇宙伽马射线开展高精度观测。GRAINE 2023 中，一台 2.5 平方米的望远镜随项目首次夜间气球飞行升空，包含对船帆座脉冲星和银心区域的观测时段。为使望远镜在低压、低温的平流层环境下工作，气球式压力容器概念被放大为内部长度 4.9 米的轻量化 gondola，研发了新型铝合金环结构和轻量化膜壳材料 SHL-300MDL。相较于 GRAINE 2018，望远镜口径增大 6.6 倍的同时，压力容器 gondola 质量被限制在 179 千克以内。对完成的飞行组件开展地面测试，结果显示其在室温和平均温度 -66.0°C 下的压差均超过 100 hPa。该有效载荷于 2023 年 4 月从澳大利亚艾丽斯斯普林斯发射，总飞行时长约 27 小时，其中水平飞行时长为 24.3 小时。尽管夜间上部膜壳温度降至约 -60°C，水平飞行期间容器内部压力始终维持在所需的 100 hPa 以上。这些结果表明，研发的 gondola 可容纳 2.5 平方米的乳胶伽马射线望远镜，并在夜间平流层飞行中维持所需压力。目前正利用回收的乳胶数据开展天体物理和大气伽马射线的科学分析，包括对银心区域的专项分析，该研发为未来大面积 GRAINE 望远镜的重复观测提供了技术基础。
英文摘要
The Gamma-Ray Astro Imager with Nuclear Emulsion (GRAINE) project conducts precision observations of sub-GeV--GeV cosmic gamma rays using a balloon-borne nuclear-emulsion telescope with high angular resolution. In GRAINE 2023, a 2.5-m$^{2}$ telescope was flown in the project's first overnight balloon flight, including observation periods for the Vela pulsar and Galactic center region. To operate the telescope under the low-pressure and low-temperature stratospheric environment, the balloon-style pressure-vessel concept was scaled up to a lightweight gondola with an internal length of 4.9 m. A new aluminum-alloy ring structure and a lightweight membranous-shell material, SHL-300MDL, were developed. While the telescope aperture was increased by a factor of 6.6 over GRAINE 2018, the pressure-vessel gondola mass was limited to 179 kg. Ground tests of the completed flight assembly demonstrated a differential pressure above 100 hPa at room temperature and at a mean temperature of $-66.0^{\circ}$C. The payload was launched from Alice Springs, Australia, in April 2023 and achieved a total flight duration of approximately 27 h, including 24.3 h of level flight. Although the upper membranous shell reached approximately $-60^{\circ}$C at night, the vessel internal pressure remained above the required 100 hPa throughout level flight. These results demonstrate that the developed gondola can accommodate a 2.5-m$^{2}$ emulsion gamma-ray telescope and maintain the required pressure during overnight stratospheric flight. Scientific analyses of astrophysical and atmospheric gamma rays, including dedicated analysis of the Galactic center region, are ongoing using the recovered emulsion data. This development provides a technical basis for repeated observations with future large-area GRAINE telescopes.
Comments29 pages, 12 figures
