Development of Compact Magnetic Spectrometer for High-resolution Ion Beam Analysis.

The Albany high-resolution magnetic spectrometer was designed to have an energy resolution an order of magnitude better than the commonly used Si detector.

Background: MeV ion beam analysis, including Rutherford backscattering, is one of the most widely used methods of characterizing the composition of thin films of interest to microelectronics. The depth and mass resolution of these methods is generally limited by the energy resolution of the detector used. With support from NSF, SRC and the Swedish Royal Academy, a high-resolution magnetic spectrometer has been constructed for use in ion beam analysis The Albany high-resolution magnetic spectrometer was designed to have an energy resolution an order of magnitude better than the commonly used Si detector. This improved energy resolution translates into an order of magnitude improvement in the mass and depth resolution. This instrument is now operational with a resolution better than ~4 keV. Development of a longer focal plane detector to broaden the acceptance energy range of the instrument is currently underway. This detector should also work better at lower ion energies that the Si detector currently being used.

Three parallel tracks of research are being followed. These are: (1) the continued development of a focal plane detector, (2) the routine application of this high resolution facility, and (3) the study of energy loss and energy straggle in order to better interpret high resolution data.

The current state of this instrument is described in the following publications.

Compact Broad Range Magnetic Spectrometer for Use in Ion Beam Analysis.
W. A. Lanford, B. Anderberg, H. Enge, and B. Hjorvarsson, Nuclear Instruments and Methods B136-38 (1998) 1177.

Characteristics of Albany's Compact High Resolution Magnetic Spectrometer.
W. A. Lanford, S. Bedell, S. Amadon, A. Haberl, W. Skala and B. Hjorvarsson, oral presentation at 14th International Ion Beam Analysis Conference, July 22-30, 1999, Dresden, Nuclear Instruments and Methods B161-63 (2000) 202.