An amalgam assembly for a fluorescent lamp includes an exhaust tubulation closed
at a free end thereof, a glass ball disposed in the tubulation, and a mercury amalgam
body disposed in the tubulation between the glass ball and the tubulation closed
end. The tubulation is provided with a pinched portion comprising a plurality of
inwardly extending dimples separated from each other and adapted to engage the
glass ball to retain the glass ball on a central axis of the tubulation. The glass
ball rests on the dimples concentrically and gaps between the dimples allow gas
to pass therethrough between the glass ball and an inside surface of the tubulation.
