LIANG Yaqiong; LIANG Guiyun

doi:10.7498/aps.74.20241603

Abstract

This study aims to quantify the solar wind charge-exchange (SWCX) X-ray emission factor (denoted as α-value) and its dependence on solar wind parameters, solar activity cycle, and solar wind origin. By analyzing 13-year (1998–2011) in-situ measurements from the advanced composition explorer (ACE) spacecraft, we investigate the statistical correlations between solar wind ionization states, elemental abundances (particularly oxygen), and bulk plasma parameters (proton speed, density). The derived α-values are critical for explaining the data from solar wind and magnetosphere interaction linker explorer (SMILE), and disentangling SWCX foreground emissions from diffuse astrophysical X-ray sources observed by Einstein Probe (EP) and proposed diffuse X-ray explorer (DIXE) payload on Chinese space station. In this work, high-resolution solar wind ion composition data and plasma parameters from ACE are investigated. Events are categorized by solar wind origin (coronal holes, streamers, interplanetary coronal mass ejections (ICMEs)) and solar cycle phase (minimum vs. maximum). The α-value, defined as the total soft X-ray photon emission cross section per solar wind proton, is computed using an updated charge-exchange model that combines the state-resolved cross-section for highly charged ions. The model takes into consideration the velocity-dependent cross-section of solar wind-neutral interaction. Statistical method and bin-averaging techniques are adopted to extract the relations between α, solar wind speed (v_sw), proton density (n_p), and oxygen abundance. The main results are as follows.1) Ionization state dynamics: A strong anti-correlation exists between solar wind ionization degree and bulk speed: high-speed winds (> 500 km/s) exhibit lower ionization states than slow-speed winds (< 400 km/s).2) Elemental abundance trends: Oxygen abundance ([O/H]) is inversely correlated with n_p: the [O/H] of denser solar wind plasmas (n_p > 13 cm^–3) decreases by 30%–50%, indicating the presence of fractionation during plasma acceleration. No significant speed dependence of [O/H] is observed, compared with earlier research results.3) Emission factor (α-value) behavior: α-value decreases rapidly with the increase of n_p and stabilizes for n_p > 13 cm⁻³. Conversely, α-value increases gradually with v_sw up to 430 km/s, beyond which it plateaus. The ICME-associated α exceeds streamer and coronal hole values by 35%–60%, which is attributed to higher averaged ionic state in transient ejecta. Solar maximum α (2000–2002) is 1.3–2.7 times higher than solar minimum (2008–2010), reflecting cycle-dependent ion composition changes. By bridging in-situ solar wind measurements and X-ray emission physics, this work enhances the ability to diagnose solar wind-magnetosphere coupling and diffuse X-ray background. The validated α-value will be of benefit to the data analysis for Chinese aerospace projects in the 2020s, such as SMILE, DIXE, and EP.

Keywords:

Authors and contacts

LIANG Yaqiong¹,
LIANG Guiyun²

Corresponding author: LIANG Guiyun, gyliang@bao.ac.cn

Funds: Project supported by the National Natural Science Foundation of China (Grant No. 12373027), the National Key R&D Program of China (Grant No. 2022YFA1603204), and the Strategic Priority Research Program (A/B) of Chinese Academy of Sciences (Grant Nos. XDA25030500, XDB34020205).

FullText HTML

References

[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]
[35]
[36]

Cited By

DownLoad: Full-Size Img PowerPoint

太阳风离子	数据类型	数据来源
O⁷⁺	总截面	Zhang等^[27]
O⁸⁺	nl分辨	Wu (email通迅)
O⁶⁺	nl分辨	Wu等^[28]
C⁶⁺	总截面	Gu等拟合公式^[18]
C⁵⁺	nl分辨	Nolte等^[29]
Ne⁹⁺	nl分辨	Liu等^[30]
Ne⁸⁺	nl分辨	Liu等^[30]
Mg¹⁰⁺	总截面	Gu等拟合公式^[18]
Mg^{8+, 9+}	总截面	Midha & Gupta经验公式^[25]
Si^(7–10)+	总截面	Midha & Gupta经验公式^[25]
Fe^(8–12)+	总截面	Wargelin等经验公式^[26]

DownLoad: CSV

[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]
[35]
[36]

[1]	CHAN Ying, YAN Yujie, WU Yuetong, WANG Qisi. Research progress of resonant X-ray scattering of charge order in cuprate superconductors. Acta Physica Sinica, 2025, 74(8): 087402. doi: 10.7498/aps.74.20241402
[2]	Li Qi-Zhi, Zhang Shi-Long, Peng Ying-Ying. Resonant inelastic X-ray scattering study of charge density waves and elementary excitations in cuprate superconductors. Acta Physica Sinica, 2024, 73(19): 197401. doi: 10.7498/aps.73.20240983
[3]	Liu Chao, Liu Shi-Long, Yang Yi, Feng Jing, Li Yu-Zhao. K X-ray emission and kinetic energy-nuclear charge relationship of ²⁵²Cf spontaneous fission. Acta Physica Sinica, 2024, 73(14): 142501. doi: 10.7498/aps.73.20240563
[4]	Xu Jia-Wei, Xu Chuan-Xi, Zhang Rui-Tian, Zhu Xiao-Long, Feng Wen-Tian, Zhao Dong-Mei, Liang Gui-Yun, Guo Da-Long, Gao Yong, Zhang Shao-Feng, Su Mao-Gen, Ma Xin-Wen. Experimental measurement of state-selective charge exchange and test of astrophysics soft X-ray emission model. Acta Physica Sinica, 2021, 70(8): 080702. doi: 10.7498/aps.70.20201685
[5]	Liang Chang-Hui, Zhang Xiao-An, Li Yao-Zong, Zhao Yong-Tao, Mei Ce-Xiang, Zhou Xian-Ming, Xiao Guo-Qing. Study of X-ray spectrum emitted due to the impact of 129Xeq+ on different ion's charge on Au. Acta Physica Sinica, 2015, 64(5): 053201. doi: 10.7498/aps.64.053201
[6]	Shi Hong, Tian Li-Cheng, Yang Sheng-Sheng. Analysis of data obtained by the solar wind ion detector onboard the Chang’E-1 Lunar orbiter. Acta Physica Sinica, 2014, 63(6): 069601. doi: 10.7498/aps.63.069601
[7]	Han Lu-Hui, Zhang Chong-Hong, Zhang Li-Qing, Yang Yi-Tao, Song Yin, Sun You-Mei. X-ray photoelectron spectroscopy study on GaN crystal irradiated by slow highly charged ions. Acta Physica Sinica, 2010, 59(7): 4584-4590. doi: 10.7498/aps.59.4584
[8]	Yuan Yong-Teng, Hao Yi-Dan, Zhao Zong-Qing, Hou Li-Fei, Miao Wen-Yong. Dynamic range of X-ray streak camera affected by space charge effect. Acta Physica Sinica, 2010, 59(10): 6963-6968. doi: 10.7498/aps.59.6963
[9]	Yang Zhi-Hu, Song Zhang-Yong, Chen Xi-Meng, Zhang Xiao-An, Zhang Yan-Ping, Zhao Yong-Tao, Cui Ying, Zhang Hong-Qiang, Xu Xu, Shao Jian-Xiong, Yu De-Yang, Cai Xiao-Hong. X-ray emission produced by interaction of highly ionized Arq+ ions with metallic targets. Acta Physica Sinica, 2006, 55(5): 2221-2227. doi: 10.7498/aps.55.2221
[10]	Yang Chao-Wen, Miao Jing-Wei, Wang Guang-Lin, Liu Xiao-Dong, Shi Mian-Gong. The electron exchange of MeV hydrogen micro-cluster ions with solids. Acta Physica Sinica, 2006, 55(11): 5810-5814. doi: 10.7498/aps.55.5810
[11]	Guo Guan-Jun, Su Lin, Bi Si-Wen. Polarimetric microwave radiation of wind-roughened sea surfaces. Acta Physica Sinica, 2005, 54(5): 2448-2452. doi: 10.7498/aps.54.2448
[12]	Yang Bai-Fang, Miao Jing-Wei, Yang Chao-Wen, Shi Mian-Gong, Tang A-You, Liu Xiao-Dong. . Acta Physica Sinica, 2002, 51(1): 55-62. doi: 10.7498/aps.51.55
[13]	. . Acta Physica Sinica, 2000, 49(2): 282-287. doi: 10.7498/aps.49.282
[14]	XU ZHANG-CHENG, GUO CHANG-LIN, ZHAO ZONG-YAN, XU JIA-YUE, ZHOU SHENG-MING, QI ZE-MING, T. FUKAMACHI, R. NEGISHI, T. NAKAJIMA. RESONANT X-RAY DYNAMICAL DIFFRACTION METHOD FOR DETERMINING TEMPERATURE FACTOR. Acta Physica Sinica, 1998, 47(9): 1520-1528. doi: 10.7498/aps.47.1520
[15]	LIU SHENG-XIA. MASS RESOLVING CHARGE-EXCHANGE NEUTRAL PARTICLE MEASUREMENT ON HT-7 TOKAMAK. Acta Physica Sinica, 1998, 47(7): 1118-1122. doi: 10.7498/aps.47.1118
[16]	LIU SHENG-XIA. ANALYSIS OF CHARGE-EXCHANGE SPECTRA DURING NBI HEATING IN THE HT-6M TOKAMAK. Acta Physica Sinica, 1996, 45(3): 449-454. doi: 10.7498/aps.45.449
[17]	WANG YAN-SEN, PAN LI-MIN, HUANG FA-YANG, FANG DU-FEI, TANG JIA-YONG, YANG FU-JIA. CHARGE-EXCHANGE OF CESIUM ION/ATOM WITH METAL SURFACES. Acta Physica Sinica, 1994, 43(12): 1950-1956. doi: 10.7498/aps.43.1950
[18]	JIN CHUN-LIN, LI ZHONG, ZANG DE-HONG, YE HUI, TANG JIA-YONG, YANG FU-JIA. CHARGE TRANSFER BETWEEN ALKALI ATOMS AND W,Pt SURFACES. Acta Physica Sinica, 1993, 42(9): 1410-1415. doi: 10.7498/aps.42.1410
[19]	LIU QIANG, WANG JIAN-ZHONG, XU XIANG-DONG, CHEN XUE-JUN. EXPONENTIAL VARIATION METHOD FOR CHARGE EXCHANGE IN H++ H COLLISIONS. Acta Physica Sinica, 1991, 40(10): 1590-1594. doi: 10.7498/aps.40.1590
[20]	GU YUAN-XIN, GE PEI-WEN, ZHAO YA-QIN, HU BO-QING, WU LAN-SHENG, FU QUAN-GUI. X-RAY TOPOGRAPHICAL STUDY ON DEFECTS IN α-LiIO₃ DECORATED BY SPACE CHARGE DUE TO THE APPLIED DC FIELDS. Acta Physica Sinica, 1980, 29(6): 711-717. doi: 10.7498/aps.29.711

Catalog

Vol. 74, Issue 10 - 2025-05-20

Metrics

Abstract views: 376
PDF Downloads: 3
Cited By: 0

姓名
邮箱
手机号码
标题
留言内容
验证码

Search

Article

留言板

Abstract

Authors and contacts

Corresponding author: LIANG Guiyun, gyliang@bao.ac.cn

FullText HTML

References

Cited By

Catalog

Metrics

Authors

Referees

About Journal

About

Search

Article

留言板

Abstract

Authors and contacts

Corresponding author: LIANG Guiyun, gyliang@bao.ac.cn

FullText HTML

References

Cited By

Catalog

Metrics

Publishing process

Authors

Referees

About Journal

About