Experimental studies of the effect of instrumental parameters and kinetic energy release on the shape of metastable peaks obtained in a linked scan at constant B/E

Abstract

The limit of resolution obtained by scanning the magnetic ( B) and electric ( E) sector fields simultaneously, such that the ratio B/E remains constant, has been investigated using the prototype “reversed” geometry ZAB—2F mass spectrometer. The resolution can be increased only marginally by closing the source, intermediate and final resolving slits. The attainable resolution has been found to depend upon three basic parameters: (1) the magnitude of the kinetic energy release ( T) accompanying the fragmentation process. The resolution can vary by as much as a factor of ten, depending upon the magnitude of this energy release; (2) the dimensions of the slits of the instrument in the Z-direction can also influence the maximum attainable resolution. By closing the slits simultaneously in the Y and Z directions, the resolution may be increased by as much as a factor of three, depending on the value of T; (3) reducing the dimensions of the source ion exit slit from the normal values used on the ZAB—2F results in a further increase in resolution by as much as a factor of two depending on the value of T. A maximum resolution between adjacent peaks in a linked scan at constant B/E of 2000 was finally achieved.