Experimental study of the fragmentation of van der Waals gas clusters by electron ionization

25th International Conference on Vacuum Technique and Technology

Chinenov, S.T.^1 ; Zarvin, A.E.^1 ; Khudozhitkov, V.E.^1 ; Kalyada, V.V.^1 ; Yaskin, A.S.^1

Department of Applied Physics, Novosibirsk State University, Novosibirsk

630090, Russia^1

关键词: Cluster distributions;    Comparison of mass spectrum;    Electron energies;    Electron ionization;    Percentage composition;    Quadrupole mass spectrometer;    Quadrupole mass spectrometry;    Supersonic nozzles;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/387/1/012012/pdf
DOI  :  10.1088/1757-899X/387/1/012012

来源: IOP

【 摘 要 】

The fragmentation of gas clusters of argon, nitrogen and methane during ionization by electron impact have been examined. Clusters were formed when the gas flowed through the supersonic nozzle into the vacuum. A molecular beam was selected from the supersonic jet by the skimmer, then it reached the analyzer of the quadrupole mass spectrometer Hiden Epic 1000. The ionization of the gas was carried out in the molecular beam by the intrinsic ionizer of the detector with an electron energy of 70 eV and in the supersonic jet by an electron beam (10 keV). A comparison of mass spectra obtained by both methods with different parameters of the supersonic jet has been done. The difference of the obtained cluster distribution has been substantiated; the disadvantages of using the classical configuration of quadrupole mass spectrometry have been analyzed. Dependences of the percentage composition of the recorded flows have been obtained. Distinctive "magic" cluster numbers have been found.