Gertrude F. Rempfer
Professor Emerita of Physics

Office Phone: 503-725-3839

Office Location: 220 Science Building 1

Email: rempferg@pdx.edu

Research Interests

Dr. Rempfer specializes in electron optics. She collaborates with Dr. O.H. Griffth of the University of Oregon in a research program being carried out jointly at Portland State University and the University of Oregon. This work involves photoelectron microscopy (PEM), low-energy reflection electron microscopy (LEEM), and aberration correction. In PEM, electrons are liberated from the specimen surface by the action of ultraviolet light, and are accelerated prior to being imaged by an electron lens system. The electron beam carries information about the spatial distribution of the photoelectron yield, and also about the topographic details and microfields at the specimen surface. In LEEM, low-energy electrons are reflected, rather than emitted, from the specimen surface. The electrons in the illuminating beam are decelerated to very low energies before interacting with the specimen. After reflection the electrons are re-accelerated and imaged, as in a photoelectron microscope, except that a means must be provided for separating the illuminating and imaging beams. The PEM and LEEM instruments at U of O and PSU are being applied in cell biology research. The purpose of the aberration-correction experiments is to compensate the spherical and chromatic aberrations of electron optical systems. The method is based on an electron mirror, which has aberrations of opposite sign from those of electron lenses. Our immediate aim is to incorporate the corrector into an advanced design of photoelectron microscope.

Selected Publications

Electron Optical Benches for In-Line and Branched Systems. A New Bench Designed for Mirror- Based Aberration Correction and Low Energy Electron Microscopy. Walter P. Skoczylas, Gertrude F. Rempfer and O. Hayes Griffith, Rev. Sci. Instrum. 65 (October 1994).

Photoelectron Imaging of DNA: A Study of Substrates and Contrast. Douglas L. Habliston, G. Bruce Birrell, O. Hayes Griffith and Gertrude F. Rempfer, J. Phys. Chem. 97:3022-3027 (1993).

Electrostatic Electron Optics in the 1940s and Today. Gertrude F. Rempfer, MSA Bulletin 23:153-158 (1993).

Low-Energy Electron Microscopy (LEEM) and Mirror Electron Microscopy (MEM) of Biological Specimens: Preliminary Results with a Novel Separating System. O. Hayes Griffith, Karen K. Hedberg, Denis Deloge and Gertrude F. Rempfer, J. Microsc. 168:249-258 (1992).

Correction of Chromatic Aberration with an Electron Mirror. G.F. Rempfer and M.S. Mauck, Optik 92:3-8 (1992)

Course Information

Electron Optics: This course is offered in Summer term, 2001. Please look here for more information about the course and course materials.