Transcript horn fastener insulation

Two styles of horn fastener
insulation schemes
Larry Bartoszek
Bartoszek Engineering
Overview
• The fundamental difference between the
two fastener styles we have been
discussing for Horn 1 is whether the
fastener is electrically touching one half of
the outer conductor or not
– The difference is not whether the fasteners
are upstream or in the middle
– The two styles can be applied at either
location
Design already presented
• In the design I showed last week, the
fasteners are not electrically touching
either half of the outer conductor. They
are at an indeterminate floating voltage.
• To make this style work, the fasteners
must be completely surrounded by
ceramic.
• The fasteners must be able to squeeze the
connection mechanically, but not touch
electrically.
The other style
• The alternative style of fastening and
insulating is to thread the fastener into one
half of the outer conductor with a tapped
hole.
• The fastener then is electrically connected
to that half of the outer conductor and
must be isolated from the other half of the
outer conductor.
Conclusion
• Either style of insulation can be used at
either the middle or upstream ends.
– MiniBooNE uses the second style at its
upstream end
• Shortest path length to avoid voltage
breakdown on ceramic in humid helium
must be determined.
• Is there a downside to floating voltage on
the fastener? I don’t know.