\title{First order perturbative calculations for a conducting liquid jet in a solenoid}
\author{J. Gallardo, S. Kahn, R. B. Palmer, P. Thieberger, R. Weggel}
\affiliation{ Brookhaven National Laboratory\\
Upton, NY 11973}
\author{ K. McDonald}
\affiliation{Princeton University\\
Princeton, NJ 08544}
A perturbative calculation is given of the behavior of a continuous
jet of conducting fluid as it enters and leaves a solenoidal
magnetic field. It is assumed that the changes in direction, jet
cross section and velocity are small.
If the jet enters the field along,
or close, to the axis, then the
induced forces are compressive and retarding. The jet slows, suffers
an increase in hydrostatic pressure, and increases in diameter;
later, the jet re accelerates and elongates. As the jet leaves the
field, the hydrostatic pressure becomes negative, and cavitation may
occur.
If the jet enters at an angle to the axis, there are, in addition,
deflections and elliptical deformations of the jet.
Formulae are given for these effects and numerical values given for
the example of a solenoidal field with a Gaussian axial profile.