This e-log is to cover the work completed from September 9th until the 11th. 

September 9th

Today Maico completed the leak checking blank off and leak checking tool (to replace the one that was contaminated). This tool was then leak checked with C-seals and no springs at the machine shop, both halves were determined to be leak tight. 2 sets of small c-seals without divots were selected and used for leak checking the module side and the source tray side. The heat shield line was tested in the ante-room and was determined to leak. Upon further investigation it was determined that the bore of the seal gland was determined to be over sized (0.450"). Isaac then installed the blank off onto the module and pump down was started, the testing car would not stabilize so Isaac tried turning the screw more allowing for further pump down. The leak check was then completed and there was no response. The flow of helium for the target module was checked but was much lower than typical as the second valve was not fully opened. 

September 10th

With the belief that the larger bore in combination with the small c-seals was the cause of the leak Maico found and polished another block that also had a larger bore. Once polished, small c-seals without dimples were selected and tested with the machine shop leak testing cart. These seals were leak tight but upon investigation the crush zone in one section of the seals was significantly reduced. The smallest width of the crush zone was measured to be ~0.007". This result is concerning as it means that larger bore water blocks can be sealed with small c-seals but once installed there is no way to tell one block from the other. There is no data on the lifetime of this combination of seal and bore. 

Following this test a small c-seal with dimples was selected and checked in the large bore. This combination resulted in a significant leak. Following that test the large c-seals were crushed in the larger bore water block. The torque required to crush the seal and to have the faces touch was more than that of a small c-seal regardless of what size bore it was crushed in. However with the larger bore the large c-seals could be completely crushed allowing for the copper faces to touch (the total force on the faces is unknown). The crushed seal was then inspected, it had a nice uniform crush zone that was relatively large when compared to a properly crushed small c-seal. Another testing with the large seal and a 0.025" wire diameter spring was completed. It was found that the wire interferes with the the seal when it exits from the groove. This interference causes a localized increased crushed zone but does not reduce the crush elsewhere or prevent the copper faces from touching. At this point it was decided to repair the heat shield using large seals. Large seals with springs were tested on the actual HS line in the anteroom and yielded that same results. The line was then installed by Maico inside the HC. It pumped down to the lower limit of the leak testing cart and sprayed with helium, no leak was detected. The containment box was then put back on by Isaac and Grant in preparation for a module move.

September 11th

Today the containment box installation was completed and the module moved. Following that Maico and myself entered into the ante-room and retrieved the blank off block from the HC via the tool port. The large c-seal used in the test and the small ones used in the blank off were then collected and bagged. The large c-seal had typical measurements. The small c-seals used in the blank off did not have typical measurements. They had not been compressed as much and the crush zone was near impossible to see (if visible at all). From the measurements it is believed that the block was not sufficiently tightened. It also calls into question the validity of the leak check due to the combination of less helium and reduced crush. 

After these measurements the tools that were contaminated but were to be recovered were bagged and checked by safety. They have been moved to the jacks area where Maico will decontaminate them. The old wiring harness from TM3 was bagged and given to safety for storage in the cyclotron tunnel. The plastic and all of the garbage was then lifted, bagged, and removed from the ante room. Safety surveyed the anteroom following this no alpha contamination was found but there was 5000 counts on the floor of the ante room. The contamination may have existed prior to this work.

Many pictures of the cseals have been taken and have been put into \\trwindata\remote handling\Photos\2013\2013_tm3_source_tray_refurb. A report detailing all of the testing and results would be invaluable.