Methods of calibrating kinetic energy release in dissociation process of molecular dications

doi:10.7498/aps.69.20200901

	Methods of calibrating kinetic energy release in dissociation process of molecular dications
	Zhang Min 1,2; Yan Shun-Cheng 1,2; Gao Yong 1,2; Zhang Shao-Feng 1,2; Ma Xin-Wen 1,2
刊名	ACTA PHYSICA SINICA
	2020-10-20
卷号	69 期号:20 页码:7
关键词	reconstruction of momentum calibration kinetic energy release reaction microscope
ISSN号	1000-3290
DOI	10.7498/aps.69.20200901
通讯作者	Zhang Shao-Feng(zhangshf@impcas.ac.cn) ; Ma Xin-Wen(x.ma@impcas.ac.cn)
英文摘要	In the studies of fragmentation processes of molecules induced by extreme ultraviolet photons, intense laser fields, or charged particles, kinetic energy release (KER) is a key physical parameter. It can reveal the electronic states of the parent molecular ion, and provide an insight into the molecular structures and the dissociation dynamics. Therefore, it is essential to obtain the accurate KER spectrum for studying the fragmentation process of molecules. However, in the experiments using reaction microscope, experimental parameters such as the timeof-flight (TOF), the voltage of the TOF spectrometer and the detector image of the fragments have significant influence on the accuracy of KER determination. In this work, by taking the two-body fragmentation process of CO2+-> C+ + O+ induced by 108 keV/u Ne8+ impact on CO molecules as a prototype, we introduce two methods to accurately calibrate the reconstructed KER spectrum. The first method is to employ two-dimensional momentum spectra of C+ ions obtained by slicing the momentum sphere. The parameters are correctly calibrated when the circular distribution of the two-dimensional ion momentum image is restored. The second method is to use the correlation spectra of the KER as a function of the emission angle of the C+ ions to calibrate the experimental parameters, the calibration meets the required level only when the linear dependence of the emission angle on the KER is fulfilled. Then, calibrated KER spectrum is obtained for the dissociation process. By fitting the peak dissociated from the (3)Sigma(+) state of CO2+ in the KER spectrum, the energy resolution is estimated at 0.24 eV under these experimental conditions. Although these two methods can be used to accurately calibrate the reconstructed KER spectrum, the second calibration method does not require particularly high data statistics, and is suitable for analyzing the processes with lower reaction cross section. Furthermore, this method is convenient for debugging the parameters. Both methods are reliable for parameter calibration and guarantee high accuracy KER for molecular fragmentation experiments in future.
资助项目	National Key R&D Program of China[2017YFA0402300] ; National Natural Science Foundation of China[11804347]
WOS研究方向	Physics
语种	英语
出版者	CHINESE PHYSICAL SOC
WOS记录号	WOS:000592460800008
资助机构	National Key R&D Program of China ; National Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://119.78.100.186/handle/113462/138450]
专题	中国科学院近代物理研究所
通讯作者	Zhang Shao-Feng; Ma Xin-Wen
作者单位	1.Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Zhang Min,Yan Shun-Cheng,Gao Yong,et al. Methods of calibrating kinetic energy release in dissociation process of molecular dications[J]. ACTA PHYSICA SINICA,2020,69(20):7.
APA	Zhang Min,Yan Shun-Cheng,Gao Yong,Zhang Shao-Feng,&Ma Xin-Wen.(2020).Methods of calibrating kinetic energy release in dissociation process of molecular dications.ACTA PHYSICA SINICA,69(20),7.
MLA	Zhang Min,et al."Methods of calibrating kinetic energy release in dissociation process of molecular dications".ACTA PHYSICA SINICA 69.20(2020):7.