The Electrostatic Ion Beam Trap : a mass spectrometer of infinite mass range

摘要

We study the ions dynamics inside an Electrostatic Ion Beam Trap (EIBT) andshow that the stability of the trapping is ruled by a Hill's equation. Thisunexpectedly demonstrates that an EIBT, in the reference frame of the ionsworks very similar to a quadrupole trap. The parallelism between these twokinds of traps is illustrated by comparing experimental and theoreticalstability diagrams of the EIBT. The main difference with quadrupole traps isthat the stability depends only on the ratio of the acceleration and trappingelectrostatic potentials, not on the mass nor the charge of the ions. All kindsof ions can be trapped simultaneously and since parametric resonances areproportional to the square root of the charge/mass ratio the EIBT can be usedas a mass spectrometer of infinite mass range.