The development of a high resolution mass spectrometer: A reminiscence

This article is a review of the events leading to the development of the double-focusing tandem mass spectrometer system, which is sometimes called the Johnson-Nier geometry. An essential feature of the geometry is that it eliminates second-order angular aberration, enhancing the sensitivity, without a loss in resolution. Flexibility in the choice of ion source and collector designs is assured because both are outside of regions of electric and magnetic fields. The vacuum housing permits high-temperature baking, ensuring ultrahigh vacuum conditions. Although introduced initially for the purpose of determining precise atomic masses, the design has found its greatest application in studies of structure of heavy molecules, making use of the high resolution to identify fragments. In many cases the composition of a molecule, or fragment, can be deduced from its exact mass by utilizing the known atomic masses of likely constituent atoms.     

Simplified spectral phase interferometry for direct electric-field reconstruction by using a thick nonlinear crystal

We propose and demonstrate a novel implementation of spectral-shearing interferometry (SSI) for reconstructing the electric field of ultrashort pulses by utilizing asymmetric group velocity matching in a long nonlinear crystal. The proposed configuration eliminates the requirement for a linearly chirped auxiliary pulse that is in common in all existing SSI methods, relying on nonlinear conversion to produce a spectral shear.     

Covariant Spectator Theory: Foundations and Applications

We provide a short overview of the covariant spectator theory and its applications. The basic ideas are introduced through the example of a ${\phi^4}$ -type theory. High-precision models of the two-nucleon interaction are presented and the results of their use in calculations of properties of the two- and three-nucleon systems are discussed. A short summary of applications of this framework to other few-body systems is also presented.