BW January 2014

On January 2, I helped straighten a bundle after cleaning a bundle that had already been straightened. Then I revised an old version of the straightening procedure and typed two other procedures.

On January 6, Liana and I emptied and dried the fish tank, washed it with warm water, and dried it again. We polished light guides. It took me much longer than it took her. I might have been pressing too hard. I measured the length and width of 30 scintillating fibers. I counted scintillating fibers and put them in relabeled bags.

On January 7, I learned how to screw the collars onto the Unistrut bar. I scraped rust off the bar with a damp cloth. Kenny and I made two bundles of fibers for Brendan to mill. The collars have to be 65 10/16" apart on the outside. I polished a bundle of light guides and then polished some individual fibers that had not been polished enough in the bundle.

On January 8, I went to the machine shop with Jon to pick up a milled bundle. I put a bundle on the Unistrut bar to be straightened, and I cleaned some fibers that Jon had polished.

On January 13, I polished bundles of scintillating fibers. Sometimes when I put fibers into the collar, I noticed some static cling between the fibers and my gloves and also between the fibers and the collar. The attraction to the gloves was not helpful because the fibers would fall out of the collar when I drew my hand away. The attraction between the metal and the fibers, however, was useful. It could be a tight squeeze to fit the last few fibers into the collar, but not so tight if the uppermost fibers were stuck to the top of the collar. Pulling the collar halves apart a little would widen a small space enough for the thirty-first through thirty-sixth fibers to fit into the collar easily.

On January 16, I began to bundle light guides for milling by myself. I put a collar around the fibers at one end, then put another collar on at the same end. Once the second collar was tight, I slid the first collar toward the other end of the fibers. Then I noticed that at certain points there was a gap between the fibers in the bundle and the collar even though the collar was tight. Consequently, a few fibers could slip even though most could not. I brought the problem to Ann Marie and Liana, and Liana came over to fix it. Eventually the fibers were tight to our satisfaction.

On January 17, I swept the lab and polished two bundles of light guides.

We want to know what dirty fibers look like and how they affect performance. To that end, I took photographs of calcium deposits from straightening and specks from milling on the fibers. Then I helped Ann Marie take more photos. Since there was too much glare on the fibers to take a good photo from directly above them, I shaded the fibers with my notebook while Ann Marie took pictures. Then Ann Marie wanted pictures of light shining through the dirty fibers. She used a green laser. I held the switch to shine the laser and she took pictures. Where there were fingerprints on the fibers, the light was brighter because it was leaking. Ann Marie also got pictures of rust on the fibers.

After uploading the pictures to Ann Marie's Google Drive and discarding some inferior ones, I polished the second bundle of light guides. Ann Marie had finished the first bundle while I was uploading the pictures. I cleaned the polished fibers from the second bundle. Next I put another bundle into a collar to be straightened. Ann Marie and I mounted the bundle on the new aluminum bar.

When the straightening pipe was full of water, I cleaned out the fish tank.

I learned some useful skills in the lab during the winter break. I learned how to use an Allen key to drive a screw up into a hole in a collar even though I could not see through the collar to make sure the screw and the hole were lined up right. When I first tried to do that, I kept looking under the bar so I could put the screw into the hole. But looking at the screw from the side would require simultaneously judging whether the screw and the hole are the same distance away, turning the Allen key in the correct direction, and holding the key sufficiently vertical. Such coordination was too much. It turned out to be easier to overcome the impulse to look at the screw, set the collar over the screw so that it looked right from above, and turn the key.

Another skill I acquired this winter was tearing duct tape tolerably well. Previously, I was very likely to wrinkle the tape if I tried to tear it. When we had to tape sheets of paper to the table for polishing the fibers, I wanted Ann Marie and Liana to handle that sticky business. One day, though, I found that by holding the tape against the roll at some point, I could tear off a piece right next to where I was holding it. Hold the tape down with one hand, and with the other pull the edge away from the roll. It was amazing.