A Large-Area Optical Time Projection Chamber for Hard X-ray Polarimetry with Directional Imaging of Low-Energy Electron Recoils
Gran Sasso Science Institute(格兰萨索科学研究所);INFN Laboratori Nazionali del Gran Sasso(意大利国家核物理研究所大萨索国家实验室);INFN Laboratori Nazionali di Frascati(意大利国家核物理研究所弗拉斯卡蒂国家实验室);IAPS - INAF Istituto di Astrofisica e Planetologia Spaziali(空间天体物理学和行星学研究所-意大利国家天体物理研究所)
Davide Fiorina, Elisabetta Baracchini, Giorgio Dho, Paolo Soffitta, Samuele Torelli, David J. M. Marques, Enrico Costa, Sergio Fabiani, Fabio Muleri, Giovanni M… 展开作者
Davide Fiorina, Elisabetta Baracchini, Giorgio Dho, Paolo Soffitta, Samuele Torelli, David J. M. Marques, Enrico Costa, Sergio Fabiani, Fabio Muleri, Giovanni Mazzitelli, Atul Prajapati
We report on the development of a large-volume, wide field-of-view time projection chamber (TPC) for X-ray polarimetry, featuring a triple-GEM amplification stage and optical readout. Originally developed within the CYGNO program for directional dark matter searches, the system employs a scientific CMOS (sCMOS) camera and a photomultiplier tube (PMT) to collect secondary scintillation light produced during charge amplification. A prototype with a cylindrical active volume (radius 3.7 cm, height 5 cm) was tested at the INAF--IAPS calibration facility (Rome, Tor Vergata) to assess sensitivity to low-energy electron directionality. We fully reconstruct electrons in the 10-60 keV range, obtain angular resolutions as good as 15°, and infer modulation factors up to 0.9. These first results demonstrate robust photoelectron tracking at tens of keV with strong modulation, indicating that photoelectric-effect polarimetry can be extended to higher energies. This capability is promising for rapid transients (GRBs, solar flares) and would broaden the astrophysical reach of X-ray polarimetry.
MIMAC low energy electron-recoil discrimination measured with fast neutrons
MIMAC(MIcro-TPC MATERIAL of Chambers)是一个定向WIMP暗物质探测器项目。直接的暗物质实验需要高水平的电子/反冲鉴别来寻找由WIMP-核弹性散射产生的核反冲。在本文中,我们提出了一个原始的方法,电子事件拒绝的基础上,应用于实验数据采集单色中子场的多元分析。该分析表明,$10^5$抑制功率对于电子/反冲辨别是可达到的。此外,通过蒙特卡罗模拟估计效率,表明在考虑全能量范围的情况下,利用$86.49\pm 0.17$ \%的核反冲效率达到105电子排斥功率,并且在考虑5 keV的低阈值的情况下,利用$94.67\pm0.19$ \%的核反冲效率达到105电子排斥功率。
Three-dimensional recoil-electron reconstruction using combined optical imaging and waveform readout for electron-tracking Compton cameras
National Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ)(国家产业技术综合研究所(AIST),日本国家计量院(NMIJ));Graduate School of Natural Science and Technology, Kanazawa University(金泽大学自然科学技术研究学院);Institute for Cosmic Ray Research, University of Tokyo(东京大学宇宙线研究所);Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(日本宇宙航空研究开发机构宇宙科学研究所)