J. W. Amy

Soft landing of ions as a means of surface modification

Abstract Chemical reactions between low energy mono-, di- and triatomic ions and metal targets lead to products which have been examined using ESCA. The nature, charge state and kinetic energy of the reactant ion all cause changes in the ESCA spectra. Results for the reactions of lead with various sulfur-containing ions (CS2+, CS22+, CS+, S+, S2+) are emphasized. A complex chemistry is involved with the sulfur being present in at least three charge states characteristic of the metal sulfide, elemental or organic sulfur and sulfur in positive oxidation states, respectively.

The study of meta-stable positive ions with a double-focussing mass spectrometer: Part I. Description of the instrument used and its performance

Abstract The instrument used in these studies is the RMH-2 mass spectrometer, of Nier-Johnson geometry having 70° electrostatic and magnetic sectors with an ion radius of 500 mm in the electric and 400 mm in the magnetic sectors. When operated at 10 kV a resolving power of 90,000 has been obtained. Typical energy profiles of the ion beam at 5 kV energy are shown having widths at half-height of ±0.26 V. The focussed ion beam at the source slit is about 0.08 mm wide. Curves obtained when the accelerating voltage is scanned at fixed electric sector voltage show a “third” field-free region in this instrument in which decomposition of meta-stable ions can be studied.

The ion kinetic energy spectrum and the mass spectrum of argon

Abstract The technique of Ion Kinetic Energy Spectroscopy (I.K.E.S.) is described and results obtained with a sample of argon gas are discussed. When coupled with conventional mass spectroscopy, the technique enables the route to formation of the ions in the mass spectrum to be deduced. It can provide information on unimolecular or collision-induced decompositions of meta-stable ions. Its application to the study of the reactions of high-kinetic energy argon ions with nitrogen molecules is described.

Building mass spectrometers and a philosophy of research

Development of the techniques of ion kinetic energy spectrometry and mass-analyzed ion kinetic energy spectrometry is described. The extension of these concepts to the method of tandem mass spectrometry for direct mixture analysis is traced, and a rationale for the construction of hybrid mass spectrometers is presented. Collisions of polyatomic ions with surfaces are discussed as an outgrowth of gaseous collisions. An attempt is made to describe a philosophy of research that guided the construction of a dozen mass spectrometers and the exploration of organic ion chemistry in as many contexts.

The study of meta-stable positive ions with a double-focussing mass spectrometer: Part II. Methods used to study “meta-stable peaks” and the sensitivity achieved with a toluene sample

Abstract The sensitivity of the model RMH-2 mass spectrometer for the study of decompositions of meta-stable ions is illustrated in the case of toluene. “Meta-stable peaks” corresponding to about 1 or 2 p.p.m. of base peak intensity can be detected. A method for scanning the mass spectrum with fixed ion accelerating voltage at a series of pre-selected electric sector voltages is described and its advantages discussed. This has enabled many new decomposition processes to be detected.