This photo was taken on 13JAN98 after Run 3 and the 8-hour vacuum bakeout on 12JAN98. Under the microscope the filament does not appear to be excessively thinned out near the break point. Therefore I believe that the breakage was due simply to clumsy handling as I disassembled the apparatus this time.

Note the heavy gray deposits on the initially white ceramic tube in the background and on the Cu wires that support the filament. Apparently the tungsten filament is evaporating at a significant rate during operation.

Credit for this nice photo goes to our new Snappy video-computer interface and our Hitachi VM-H720A Hi-8 video camera.