The window cover panel has been installed on the hot side of the NHC shielding window according to drawing IRH1638. It was necessary to drill and tap a hole in the steel frame first to achieve proper grounding for stud welding. The strength of all studs were checked by installing a nut on the stud tightened against a block up against the steel frame, which was then torqued to a minimum of 10 ft*lbs. For the final installation the nuts were each torqued to approximately 3 ft*lbs. Visibility from the cold side of the cell was checked before and after installation by Chad Fisher and Isaac Earle: no distortion was caused by the new cover panel and with the in-cell work lights aimed in a similar direction to how the permanent lights will be installed (shining down from the roof, and also aimed south from the periphery of the window) there was no significant decrease in visibility of the work space. A couple of small scratches are visible on the panel surface - these were already there when the panel arrived at TRIUMF. The panel has been installed in an orientation that will minimize the visibility of these scratches during normal work. When the work lights were aimed at the window many imperfections in the panel were visible, however this is not expected to occur during normal operation. After the cell lighting has been installed the visibility will be re-evaluated and a new panel can be procured if necessary.
|