University of Colorado（科罗拉多大学）；National Institute of Standards and Technology（美国国家标准与技术研究院）；Johns Hopkins University（约翰斯·霍普金斯大学）；NASA Goddard Space Flight Center（美国国家航空航天局戈达德太空飞行中心）
Gregory Jaehnig, John Appel, Sarah Marie Bruno, Jake Connors, Shannon M. Duff, Naina Gupta, Johannes Hubmayr, Matthew A. Koc, Tammy Lucas, Tobias Marriage, Lola… 展开作者
Gregory Jaehnig, John Appel, Sarah Marie Bruno, Jake Connors, Shannon M. Duff, Naina Gupta, Johannes Hubmayr, Matthew A. Koc, Tammy Lucas, Tobias Marriage, Lola Morales Perez, Caleigh Ryan, Jeff Van Lanen
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6 pages, 9 figures, Low Temperature Detectors Conference 2025
The Cosmology Large Angular Scale Surveyor (CLASS) is an experiment designed to measure the polarization of the cosmic microwave background on large angular scales to probe cosmic reionization and search for the inflationary $B$-mode signal. CLASS is a multi-frequency ensemble of telescopes with bands centered at 40, 90, 150, and 220 GHz. Each telescope has arrays of feedhorn-coupled transition edge sensor bolometers at the focal plane. The frequency response is primarily defined by the on-chip bandpass filter with additional contributions coming from the feedhorn, orthomode transducer, and 180-degree hybrid. In this study, we compare simulations and measurements of the frequency response of single pixel witness devices in the 90 GHz band with and without the bandpass filter. For the first time, we can separate the effects of the bandpass filter from the other microwave components using Fourier transform spectroscopy and design splits of the pixel. The results show that the -3 dB band edges are at 80 GHz and 108 GHz. The measurements demonstrate a robust method for characterizing the spectral response of individual components, which is crucial for optimizing the performance of future detector arrays.
Spectral calibration and modeling of the NuSTAR CdZnTe pixel detectors
核光谱望远镜阵列（NuSTAR）将是第一个聚焦于硬X射线（5-80 keV）波段的空间飞行任务。NuSTAR仪器携带两个共对准掠入射硬X射线望远镜。每个NuSTAR焦平面由四个2 mm CdZnTe混合像素探测器组成，每个探测器的有效收集面积为2 cm x 2 cm。每个混合电路由一个32 x 32的605微米像素阵列组成，用加州理工学院定制的低噪声NuCIT ASIC读出。为了将每个像素的光谱响应特性描述为满足科学校准要求所需的程度，我们开发了一个基于Geant 4的模型，并为NuSTAR混合设计定制了Shockley-Ramo定理。该模型结合了蒙特卡罗的X射线相互作用与随后的电荷传输内的检测器。使用Co-57，Eu-155和Am-241的放射性源的该模型和校准数据的组合使我们能够确定每个像素的电子和空穴迁移率寿命产品，并将实际性能与无缺陷材料的理想性能进行比较。
Molecular Bremsstrahlung Radiation at GHz Frequencies in Air
一种与荧光技术互补的超高能宇宙射线探测技术是利用大气层中阵雨通过后留下的低能电离电子所发射的分子韧致辐射。在这篇文章中，一个详细的估计光谱强度的光子在地面上起源于这种辐射。预计从级联的高能电子的通道的光谱强度也估计。在电子/中性分子的等离子体中的光子的吸收被示出是可以忽略的。所得到的光谱强度示出为$2\times10^{-21} $ W cm $^{-2}$ GHz $^{-1}$在10公里处的簇射核心的垂直簇射引起的质子的$10^{17.5}$ eV。此外，最近的测量空气中的韧致辐射在千兆赫频率从一束电子枪产生的95 keV的电子也进行了讨论，合理地再现的模型。
Bayesian estimation of spectral parameters of the 6.7-GHz methanol maser G339.884-1.259 from GRAO observations
Ghana Space Science & technology Institute, Ghana Atomic Energy Commission（加纳空间科学与技术研究所，加纳原子能委员会）；Department of Physics and Electronics, Rhodes University（罗德斯大学物理与电子系）；Astronomy and Astrophysics Department, University of California Santa Cruz（加州大学圣克鲁斯分校天文学与天体物理学系）
