In order to use a regular
dipole as a magnetic spectrometer
the original beam pipe had to be replaced.
On one hand the replacement should be stable and vacuum tight,
on the other hand it should have very thin windows so that
the reaction product leaving the dipole region don't
scatter to much.
The solution was to design a
with rectangular cross section
with windows of two layers of carbon fiber glued to a thin
The resulting window foil is so stable, that cutting it with a knife
doesn't result in blowing it, an essential requirement when it is
used to separate normal air pressure from ultra high vacuum.
The cylinder in the left part of the picture is the
Positively charged reaction products are deflected into the inner
regoin of COSY.
Negatively charged particles cross a thin scintillation detector
and an arrangement of
pad detectors before they hit the iron of the
of the vacuum chamber on a workbench
the vacuum chamber in the workshop
Back to the
Last updated: 25-November-1997 by