论文标题
CMB极化实验的更新设计卫星Litebird
Updated design of the CMB polarization experiment satellite LiteBIRD
论文作者
论文摘要
基于地面实验的丰富经验的过渡边缘传感器(TESS)的最新发展一直使传感器技术足够成熟,以使其在未来的卫星CMB CMB极化实验中应用。 Litebird处于此类未来卫星中最先进的阶段,其目标是其在2027财政年度(2027FY)的推出,并用Jaxa的H3 Rocket推出。它将在反射性低频和折射率和高频率望远镜的焦点平面上容纳4000多个苔丝,以便通过在宇宙膨胀中预测的原始重力波检测到宇宙微波背景(CMB)上印在宇宙微波背景(CMB)上的标志。 34GHz和448GHz之间的总频率覆盖范围使我们能够通过使用CMB和前景信号之间的光谱差异来通过精确的银河前景发射来提取这种弱螺旋极化模式。将望远镜冷却至5Kelvin,以抑制热噪声,并在单个光圈处具有透射半波板的极化调节器,以将天空极化信号与人工极化分开,并从人工极化和从工具1/F噪声中缓解。通过使用V沟的被动冷却,用机械冷却器以及绝热的消灭冰箱支持主动冷却。计划进行三年的第二个Sun-Earth Lagrangian Point的天空观测。日本,美国,加拿大和欧洲之间的国际合作正在担任各种角色。 2019年5月,贾克萨(Jaxa)选择了莱特鸟(Litebird)作为战略大型任务2。
Recent developments of transition-edge sensors (TESs), based on extensive experience in ground-based experiments, have been making the sensor techniques mature enough for their application on future satellite CMB polarization experiments. LiteBIRD is in the most advanced phase among such future satellites, targeting its launch in Japanese Fiscal Year 2027 (2027FY) with JAXA's H3 rocket. It will accommodate more than 4000 TESs in focal planes of reflective low-frequency and refractive medium-and-high-frequency telescopes in order to detect a signature imprinted on the cosmic microwave background (CMB) by the primordial gravitational waves predicted in cosmic inflation. The total wide frequency coverage between 34GHz and 448GHz enables us to extract such weak spiral polarization patterns through the precise subtraction of our Galaxy's foreground emission by using spectral differences among CMB and foreground signals. Telescopes are cooled down to 5Kelvin for suppressing thermal noise and contain polarization modulators with transmissive half-wave plates at individual apertures for separating sky polarization signals from artificial polarization and for mitigating from instrumental 1/f noise. Passive cooling by using V-grooves supports active cooling with mechanical coolers as well as adiabatic demagnetization refrigerators. Sky observations from the second Sun-Earth Lagrangian point, L2, are planned for three years. An international collaboration between Japan, USA, Canada, and Europe is sharing various roles. In May 2019, the Institute of Space and Astronautical Science (ISAS), JAXA selected LiteBIRD as the strategic large mission No. 2.