Thesis (M.A.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / The general theory of the operation of a mass spectrometer is described with particular attention to the second order focusing. The equations wherever applicable are used for a symmetrical type, 90° deflection mass spectrometer with a radius of 4.6 centimeters. Since errors in the magnetic field are more serious (by a factor of 2) than errors in the electrostatic potential, a current regulator is constructed which can correct an error signal to few parts in 10^3. The beam is provided by surface ionization and the analysis of possible masses is limited by such factors as ionization potential, maximum magnetic field, and accelerating potential. A few mass spectra are given with voltage scanning, and the results are analyzed in terms of the equations derived in part I. The Bediasite sample used for analysis is from the Grimes County, Texas, and such elements as Fe, Si, Al, Mg, Na, Ne, O, N, and possibly Ti and carbon have been identified in its spectrum. The existence of elements with high ionization potential is explained to be due to a discharge process in the ionization chamber. The experimental duration of peaks due to Ne, 0, N is about 2 hours with N the most intense and Ne the least intense element. These peaks seem to be the contents of the microscopic bubbles present in the sample. The presence of neon oxygen, and helium has been confirmed by the spectroscopic analysis of O'Keefe, Dunning, and Lowman. Helium was not recorded due to the limited range of the accelerating power supply. It is suggested that in order to carry out the research further, some improvements be made on the instrument. / 2031-01-01