• Theoretical Condensed-Matter Physics
• Theoretical Elementary Particle Physics
• Astrophysics and General Relativity
• Experimental Elementary Particle Physics
• Accelerator Physics
• Experimental Condensed-Matter Physics
• Biological Physics
• Multidisciplinary Research
• Major Research Facilities
• Resources for Researchers

B.Sc., 1961, Massachusetts Institute of Technology. Ph.D., 1967, California Institute of Technology. Research Associate, CERN, 1967-68. Assistant Professor, Physics, Cornell University, 1968-74. Associate Professor, Physics, Cornell University, 1974-80. Professor, Physics, Cornell University, 1980-present. Visiting appointments include: Stanford Linear Accelerator Center; Osservatoria Astrofisico di Arcetri, Florence Italy; SSC Central Design Group, LBL. Alfred P. Sloan Fellow, 1971-74. Fellow, American Physical Society. Member, American Association for the Advancement of Science.

Research Areas
Experimental high energy particle physics; instrumentation in high energy particle physics experiments; RF acceleration systems and instrumentation for particle accelerators

Current Research

My research activities are primarily focused on accelerator physics.  Beam size measurements using optical synchrotron radiation are the main activities that I am working on at the moment.  This involves using a combination of double slit interferometry and taking advantage of the phase reversal of the electric field vector in the horizontal plane for vertically polarized synchrotron radiation.  The depth of the intensity minimum is a very sensitive way to measure small vertical beam sizes. This is part of the CesrTA program.  In addition, I am working with our superconducting RF group currently led by Prof. Georg Hoffstadter in developing high gradient superconducting RF cavities suitable for use in an electron positron linear collider.  I have developed a technique based on second sound in superfluid helium to locate the site when the quench occurs in these cavities when they are driven to very high gradients.  An array of eight tranducers can locate the quench site to a few millimeters.  This is more accurate and very much simpler than the thermometer arrays used in the past involving many hundreds of thermometers limited to only two cells of a multi-cell cavity.  Research Scientist Zack Conway is working with me on this program.  One graduate student would be welcome.

Spotlight

Michael Ehrlichman, graduate student, is working in Professor Georg Hoffstaetter’s group researching the effect of ionized residual gas on particle accelerator beams.  Residual gas molecules ionized by charged particle beams can become trapped in the potential well of the beam.  These trapped ions exert a nonlinear focusing force on the beam that can reduce beam quality.  The ions can also undergo coupled oscillations with the beam.  These coupled oscillations can become unstable and increase the effective dimensions of the beam or ...
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