The excitation and ionization of fast He+ ions passing through a thin carbon foil

[摘要] The work of this thesis is presented in three parts: 1) Charge state fractions, 2) n = 5 He populations, and 3) the biased foil and polarization experiments. The principle work of this thesis consists of the measurements of the charge state fractions of helium after passing through a thin carbon foil. The charge state fractions were analyzed by a magnetic field with the total optical radiation in the excited beam used as a reference. This method allowed the use of high beam currents and simple Faraday cup detectors. The results are in good agreement with that of Armstrong, et. al., who used single particle detectors and low beam currents. In the second part of this thesis, the charge state fractions were used to normalize the data of Jordan, Bakken, and Yager of relative populations of the n = 5 level of He. Jordan, Bakken, and Yager used the beam foil method with fast He+ ions to obtain the amplitudes and half-lives of the fine structure states in the n = 5 to n c 3 transition. In the third part of this thesis, the beam foil method was used to observe the effects of small electric field on the amplitudes and lifetimes of the fine structure states of the n = 5 to n = 3 and n = 1 to n = 3 transitions. The polarization of the radiation from these states was also observed.

[发布机构] Rice University