Resolving Zeeman Transitions of the Negative Sulfur Ion Using Photodetachment Spectroscopy. J.E. Wells, Davidson College, Davidson, North Carolina. Results. Abstract.
Resolving Zeeman Transitions of the Negative Sulfur Ion Using Photodetachment Spectroscopy
J.E. Wells, Davidson College, Davidson, North Carolina
Photodetachment from the negative sulfur ion in a magnetic field is a well studied phenomenon at the 2P3/2→3P2 transition, known as the electron affinity. It is modeled using the Blumberg, Itano, Larson (BIL) Theory. The goal of this work is to apply the BIL theory’s prediction to the less studied 2P1/2→3P2 transition. A Penning ion trap was used to trap the ions and photodetachment was achieved using a continuous wave tunable dye laser. For the first time, structure due to the magnetic field in the detachment cross-section was observed at this transition. For the first time at any transition using a 1.0-T magnetic field, evidence of individual Zeeman levels was observed.
A plot showing the fraction of ions surviving detachment as a function of photon energy. Notice that the fraction of ions surviving does not simply decrease with photon energy as it would in the absence of a magnetic field. Instead there is structure caused by a combination of the Zeeman transitions and the quantized orbits of the freed electron. The black arrows show the locations of the Zeeman transitions suggested by the data. The table below compares the Zeeman transitions measured in the experiment to the theoretical values.
This plot shows another data set which covers a much larger range of photon energies. It shows evidence of 8 Zeeman transitions, which are compared to theoretical values in the table below.
 C. Blondel, W. Chaibi, C. Delsart, and C. Drag, J. Phys. B. 39, 1409 (2006).
 C. Blondel, C. Delsart, C. Valli, S. Yiou, M.R. Godefroid and S. Van Eck, Phys. Rev. A. 64, 052504 (2001).
 P. R. Bevington, Data Reduction and Error Analysis for the
Physical Sciences(McGraw-Hill, New York, 1969).
 W. A. M. Blumberg, “Laser Photodetachment Spectroscopy of Negative Ions in a Magnetic Field” (PhD Thesis, Harvard University, 1979).
 W. A. M. Blumberg, R. M. Jopson, and D. J. Larson, Phys. Rev. Lett. 40, 1320 (1978).
 W. A. M. Blumberg, W. M. Itano, and D. J. Larson, Phys. Rev. A. 19, 139 (1979).
 C. W. Clark, Phys. Rev. A. 28, 83 (1983).
 H. G. Dehmelt and F. L. Walls, Phys. Rev. Lett. 21, 127 (1968).
 D. J. Griffiths, Introduction to Quantum Mechanics 2nd Ed (Pearson Education, Upper Saddle River, NJ, 2005).
 C. Heinemann, W. Koch, G. G. Lindner and D. Reinen, Phys. Rev. A. 52, 1024 (1995).
 G. Herzberg, Atomic Spectra and Atomic Structure (Dover Publications, New York, 1945).
 A. K. Langworthy, D. M. Pendergrast, and J. N. Yukich, Phys. Rev. A. 69, 025401 (2004).
 D. J. Larson and R. Stoneman, J. de Physique. 43, C285 (1982).
 D. J. Larson and R. Stoneman, Phys. Rev. A. 31, 2210 (1985).
 D. M. Pendergrast and J. N. Yukich, Phys. Rev. A. 67, 062721 (2003).
 B. M. Smirnov, Physics of Atoms and Ions (Springer, New York, 2003).
 E. P. Wigner, Phys. Rev. 73, 1002 (1948).
 J. N. Yukich, “Electron Wave Packets and Ramsey Interference in a Magnetic Field” (PhD Thesis, University of Virginia, 1996).
 J. N. Yukich, C. T. Butler, and D. J. Larson, Phys. Rev. A. 55, 3303 (1997).
 J. N. Yukich, T. Kramer, and C. Bracher, Phys. Rev. A. 68, 033412 (2003).
Thanks to Dr. John Yukich and the Davidson Physics Department