Friday, January 11, 2013, 10:59

The insulator that holds the terminals was broken when a target container was installed.  The insulator had seen so much heat shine from the Cu heat-shield gaps, see attachment.  Tightening the bolts on the target container might further put more force on the insulator and eventually broke it.

To prevent this to happen again.  The Cu-heat shield gaps have covered with Ta-foil to prevent any shine from the target  container onto the insulator.  Also, a torque wrench will be used to tighten the bolts on the terminals.  At this point, we don't know the max torque the insulator can tolerate.  Some measurements were done on the target resistant (ohm) as a function of torque (in pounds).  The best torque to tighten the terminal bolts is 150 lbs.