Electrostatic Ion Traps
Zajfman and co-workers have recently explored the remarkable properties of electrostatic ion traps in some detail.[1-5] They are quite simple in design and operation: in many respects they may be viewed as two reflectrons coupled together, in which the ions behave much like photons in an optical resonator. After being introduced into the trap, the ions are simply reflected back and forth many thousands of times, for periods as long as hundreds of milliseconds. Ions of different mass propagate at different frequencies inside the trap, and a ring pick-up electrode may be used to monitor the ions on each pass with single ion sensitivity. A Fourier transform of the pickup electrode signal yields the oscillation frequency, which may be converted to ion mass-to-charge ratio. The resolving power and lifetime of ions in electrostatic traps are highly dependent on the associated trajectories and energetics of the ions, with the overall efficiency of the trap being mass independent. All ions of a given kinetic energy are trapped in stable orbits.
1. High resolution mass spectrometry using a linear electrostatic ion beam trap, D. Zajfman, Y. Rudich, I. Sagi, D. Strasser, D. W. Savin, S. Goldberg, M. Rappaport, and O. Heber, Int. J. Mass Spect. 229, 55 (2003).
2. Self-bunching effect in an ion trap resonator, D. Zajfman, O. Heber, A. L. Rappaport, H. B. Pedersen, D. Strasser, and S. Goldberg, J. Opt. Soc. Am. B 20, 1028 (2003).
3. Electrostatic bottle for long-time storage of fast ion beams, D. Zajfman, O. Heber, L. VejbyChristensen, I. BenItzhak, M. Rappaport, R. Fishman, and M. Dahan, Phys. Rev. A 55, R1577 (1997).
4. New type of electrostatic ion trap for storage of fast ion beams, M. Dahan, R. Fishman, O. Heber, M. Rappaport, N. Altstein, D. Zajfman, and W. J. van der Zande, Rev. Sci. Instrum. 69, 76 (1998).
5. Self-bunching induced by negative effective mass instability in an electrostatic ion beam trap, D. Strasser, O. Heber, S. Goldberg, and D. Zajfman, J. Phys. B 36, 953 (2003).