341 research outputs found
Potential for measurement of the tensor electric and magnetic polarizabilities of the deuteron in storage-ring experiments with polarized beams
Measurement of the tensor electric and magnetic polarizabilities of the
deuteron is of great interest, especially in connection with the possibilities
of COSY and GSI. These polarizabilities can be measured in storage rings by the
frozen spin method providing a disappearance of g-2 precession. This method
will be used in the planned deuteron electric-dipole-moment experiment in
storage rings. The tensor electric polarizability of the deuteron significantly
influences the buildup of the vertical polarization in the above experiment.
The spin interactions depending on the electric dipole moment, the tensor
electric polarizability, and main systematical errors caused by field
misalignments have very different symmetries. For the considered experimental
conditions, the sensitivity to the deuteron EDM of cm
corresponds to measuring the both of tensor polarizabilities with an accuracy
of cm. This
conservative estimate can be improved by excluding the systematical error
caused by the field instability which is negligible for the measurement of the
tensor polarizabilities. To find the tensor magnetic polarizability, the
horizontal components of the polarization vector should be measured.Comment: 11 pages, the extended version of the paper prepared for the
Proceedings of 19th International Spin Physics Symposium (September 27 -
October 2, 2010, Julich, Germany
Dependence of volume FEL (VFEL) threshold conditions on undulator parameters
The idea and principles of volume free electron lasers were proposed in
[1-4]. It was shown there that volume distributed feedback (VDFB) can
essentially reduce the threshold current of generation and provide the
possibility of smooth frequency tuning. The present work considers an undulator
VFEL with multiwave VDFB. It is shown that dependence of threshold current on
the interaction length changes in the point of roots degeneration. This leads
to the sharp decrease of start current if condition of dynamical diffraction is
fulfilled. The dependence of amplification coefficient changes, too. So the
interaction length for generation appears shorter. The proposed scheme can be
used for generation in wide spectral range from microwaves to X-rays. The
operating features of undulator VFEL is considered.Comment: Latex, 6 pages with 2 Postscript figure
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