  Precise measurement of the electric dipole moments (EDM) of fundamental
charged particles would provide a significant probe of physics beyond the
standard model. Any measurably large EDM would imply violation of both time
reversal and parity conservation, with implications for the matter/anti-matter
imbalance of the universe, not currently understood within the standard model.
A frequency domain (i.e. difference of frequencies) method is proposed for
measuring the EDM of electrons or protons or, with modifications, deuterons.
Anticipated precision (i.e. reproducibility) is $10^{-30}\,$e-cm for the proton
EDM, with comparable accuracy (i.e. including systematic error). This would be
almost six orders of magnitude smaller than the present upper limit, and will
provide a stringent test of the standard model.
  Resonant polarimetry, made practical by the large polarized beam charge, is
the key (most novel, least proven) element of the method. Along with the
phase-locked, rolling polarization "Koop spin wheel," resonant polarimetry
measures beam polarization as amplitude rather than as intensity.
  The polarization roll, at 100\,Hz for example, and adjustable by a constant
control current, causes spurious torques due to field errors to average to zero
to high accuracy. Since these torques have been considered to be the dominant
source of systematic error in truly frozen spin operation, this is a major
improvement resulting from the rolling polarization. Important sources of
systematic errors remain, the main one being due to Wien filter reversal
uncertainty.
  Both electron and proton spins can be "frozen" in all-electric storage rings,
and their EDM precisions should be comparable. Freezing the deuteron spin
requires a superimposed electric and magnetic guide field; otherwise the
rolling spin method and precision should be similar.
