<p>The first pathfinder of the CATCH mission, CATCH-1, was launched in June 2024. It is equipped with a light-weight, narrow-field optimized Lobster Eye X-ray Optics. By sacrificing a portion of the field of view to achieve a large effective area, the telescope’s sensitivity is enhanced. This paper presents the equipment and procedures employed for calibrating the optics assembly. A comprehensive on-ground calibration for the Lobster Eye X-ray Optics is conducted before its launch using multi-target X-ray sources and the pnCCD Color X-Ray Camera in the 100 m X-Ray Test Facility. The results are derived from calibration measurements taken before and after the mechanical testing and mainly include measurements of the focal length, point spread function, angular resolution, and the effective area for incident X-rays at 0.28 keV, 0.93 keV, 1.49 keV, 2.98 keV, and 4.51 keV. The results indicate that the mirror’s performance remains stable and no observable variation before and after the mechanical testing. At 0.93 keV, the mirror’s angular resolution is <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10686_2025_10001_Article_IEq1.gif" Format="GIF" Height="15" Rendition="HTML" Resolution="72" Type="Linedraw" Width="35" /> </InlineMediaObject> <EquationSource Format="TEX">$6.11^{\prime }$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>6</mn> <mo>.</mo> <msup> <mn>11</mn> <mo>′</mo> </msup> </mrow> </math></EquationSource> </InlineEquation> (FWHM), and the effective area is 40.75 <InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10686_2025_10001_Article_IEq2.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="28" /> </InlineMediaObject> <EquationSource Format="TEX">$\textrm{cm}^{2}$</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mtext>cm</mtext> <mn>2</mn> </msup> </math></EquationSource> </InlineEquation>, meeting the expected performance of CATCH-1 X-ray optics.</p>

Pre-flight calibration of the optics assembly for CATCH’s first pathfinder

期刊论文
发表日期：

2025年5月8日

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Jingyu Xiao,
Yiming Huang,
Zijian Zhao,
Yusa Wang,
Qian-Qing Yin,
Chen Zhang,
Dongjie Hou,
Yuxuan Zhu,
Yifan Zhang,
Donghua Zhao,
Sheng Yang,
Lingling Men,
Ge Jin,
Lian Tao,
Shuang-Nan Zhang,
Wen Chen,
Yanfeng Dai,
Min Gao,
Huilin He,
Guoli Huang,
Zhengwei Li,
Xiaojing Liu,
Panping Li,
Yajun Li,
Ruican Ma,
Liqiang Qi,
Xiangyang Wen,
Shaolin Xiong,
Yibo Xu,
Liyuan Xiong,
Yong Yang,
Juan Zhang,
Aimei Zhang,
Heng Zhou,
Shujie Zhao,
Kang Zhao,
Qingchang Zhao

摘要

The first pathfinder of the CATCH mission, CATCH-1, was launched in June 2024. It is equipped with a light-weight, narrow-field optimized Lobster Eye X-ray Optics. By sacrificing a portion of the field of view to achieve a large effective area, the telescope’s sensitivity is enhanced. This paper presents the equipment and procedures employed for calibrating the optics assembly. A comprehensive on-ground calibration for the Lobster Eye X-ray Optics is conducted before its launch using multi-target X-ray sources and the pnCCD Color X-Ray Camera in the 100 m X-Ray Test Facility. The results are derived from calibration measurements taken before and after the mechanical testing and mainly include measurements of the focal length, point spread function, angular resolution, and the effective area for incident X-rays at 0.28 keV, 0.93 keV, 1.49 keV, 2.98 keV, and 4.51 keV. The results indicate that the mirror’s performance remains stable and no observable variation before and after the mechanical testing. At 0.93 keV, the mirror’s angular resolution is $6.11^{\prime }$ $6 . 11^{'}$ (FWHM), and the effective area is 40.75 $\textrm{cm}^{2}$ ${cm}^{2}$ , meeting the expected performance of CATCH-1 X-ray optics.