The ion beam transmission efficiency of the ion source is an important factor in determining the sensitivity of a mass spectrometer. Vauthier (1955) has shown for a simple source that the transmission efficiency is very low. The present thesis examines the transmission efficiency of a more complex source. The first part of the thesis deals with the ion optical properties of a multiple slit ion source. The region of ion withdrawal has been sketched by computing the ion trajectories passing through the exit slit. It was found that for the more complex source the region of ion withdrawal is also much smaller than the total ionization space. It is not practical to confine the ionization region to the small volume from which ions are withdrawn. The effect of a source magnetic field has been taken into account. The perturbation of the trajectory due to the field is small, and therefore the mass discrimination due to the source magnetic field is imperceptible for heavy ions unless the field is of the order of a few webers/m². The multiple slit ion source produces a divergent ion beam, only a small fraction of which penetrates the exit slit. Obviously a system producing a beam converging at the exit slit to a narrow parallel ribbon will be most efficient. In order to devise such a system a theory of the inverse problem of particle motion is developed in the second part of the thesis. A procedure was found to determine a potential distribution required to guide a group of particles along a set of prescribed paths. There are two important limitations to the choice of paths: (a) there are certain paths which are not complete; that is a particle following such a path is turned back at certain points which we call mirror points. (b) The particles which do not satisfy the initial conditions of uniform energy and direction may deviate considerably from their projected paths leading to what we have called an unstable situation. Fortunately the complete paths are stable, and the incomplete paths are unstable. Of the two types of convergent paths studied, namely, exponentially decreasing and damped oscillatory paths, the system of damped oscillatory paths is stable. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

An analysis of the most commonly used type of Ion Cyclotron Resonance (ICR) spectrometer is given. Though the equations of motion of an isolated ion in the ICR geometry are extremely non-linear, it was found possible to decouple the longtitudinal oscillations due to the trapping potential from the cyclotron motion by exploiting the fact that the cyclotron frequency is very much greater than the trapping frequency. A previously unsuspected dependence of the cyclotron frequency and drift velocity of an ion on its spatial coordinates was discovered and experimentally investigated. The distribution of energies for ions at resonance with an applied r-f electric field is also discussed and improved techniques for the study of energy dependent cross-sections are proposed. Conventional ICR techniques were used to estimate collision frequencies of sodium and potassium ions in helium and argon gases. These experiments yield information about the d.c. drift mobility, in the zero field limit, of the alkali ions in inert gases and are discussed in terms of various models of the ion-atom interaction potential. A crossed beam arrangement was used to obtain preliminary estimates of low energy rate constants for both asymmetric and symmetric resonant charge transfer between alkali ion-atom pairs. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

No description available.

No abstract provided. / Thesis / Master of Science (MSc)

No description available.

No description available.

N/A / Thesis / Master of Science (MS)

A temporally and spatially non-scanning imaging spectrometer covering two separate spectral bands in the visible region using computed tomographic imaging techniques is described. The computed tomographic techniques allow for the construction of a three-dimensional hyperspectral data cube (x, y, λ) from the two-dimensional input in a single frame time. A computer generated holographic dispersive grating is used to disperse the incoming light into several diffraction orders on a focal plane composed of interwoven pixels independently sensitive to the two bands of interest. Separating the input of the two spectral pixel types gives co-registered output between the two bands and overcomes the limitation of overlapping orders. The proof of concept in the visible is presented using a commercially available camera.The lessons learned from the visible system are applied to a dual infrared band imaging spectrometer. Utilizing recent developments in dual band infrared focal planes a dual band imaging spectrometer is designed covering portions of the MWIR and LWIR atmospheric transmission windows. The system design includes the evaluation of recent developments in dual band infrared focal planes, the design and evaluation of the computer generated holographic disperser, and the optical elements in the system.

A description of a Dempster type double focusing mass spectrograph, converted to a mass spectrometer is reported. The latter part of the thesis deals with an investigation of a Shaw type solid ion source. Ten microgram samples of VaCl2 and SrCl2 yielded measurable ion currents of 1.0 x 10-11 amperes. Results with UF4 and PbI2 are also reported. / Thesis / Master of Science (MS)

Master of Science / Department of Physics / Carlos Trallero / This report presents the details of an electron time-of-flight (ETOF) spectrometer to be used for characterizing ultrafast electric field pulses. The pulses will range in pulse-duration from femtosecond to attoseconds and in wavelength from the far infrared (FIR) to the extreme ultra violet (XUV). By measuring the photoelectrons in the presence of two electric fields and their quantum interference we will be able to extract the amplitude and phase of the electric field. For XUV pulses this is the well-known streaking and Reconstruction of Attosecond Beating by Interference of Two-Photon Transition (RABITT) method. The ETOF is based on a set of tunable electrostatic lenses capable of detecting 0-150 eV electrons. In addition, we can selectively increase the photoelectron yield of the spectrum. The precise tuning of the electrostatic lens system is done with a Genetic Algorithm (GA) with an intensity fluctuation discriminator in the fitness.