  The possibility of a significant slowdown of particles by removing them from
a localized state in an electromagnetic potential well with a fixed spatial
distribution is shown with a sufficiently slow decrease in the depth of this
well with time. It is believed that the considered particles are in high vacuum
conditions and forces acting on them are not dissipative, i.e. these particles
move without friction. Depending on whether the particles have an electric
(magnetic) dipole moment, a controlled electric (magnetic) field or nonresonant
laser radiation can be used to slow them down in this way. A detailed analysis
of the features and efficiency of the established particle deceleration
mechanism was carried out on the example of the one-dimensional rectangular
potential well based on simple mathematical relationships. The obtained results
can be used in the mechanics of micro- and nanoparticles in high vacuum, and
under certain conditions also in ultra-high resolution spectroscopy of atoms
and molecules "cooled" by the proposed method.
