Changes

= Fall 2015 =

= Fall 2015 =

During this semester I continued fusing the scintillating and light-guide fibers. I had found that the pressures Liana suggested to me perform well on strength tests--they held 1100g on average. However, over the summer I was a bit concerned with the excessive flaring that resulted from the cladding moving out of place. Some fuses resulted in lateral wings forming on the fuse site, the sizes of which could be up to 1mm. These wings had to be sanded down for the fibers to fit in their final housing at Jefferson Lab, and it is of some concern that sanding removes the cladding about the fuse site and promotes light loss. A razor blade could be used to slice the wings off closer to the fuse site and minimize sanding, but my concern persisted. After consulting with Jim, I fused a few spare light guide lengths to each other and re-calibrated the fusing pressures. High lateral or vertical pressure both produced wings, but too low of a pressure would result in the fiber cores not fully fusing. Fuses with 86psi vertical pressure and 24psi lateral pressure resulted in the smallest wings possible while performing relatively well on strength tests. On average, a fuse at these pressures would break at about 1000g.

During this semester I continued fusing the scintillating and light-guide fibers. I had found that the pressures Liana suggested to me perform well on strength tests--they held 1100g on average. However, over the summer I was a bit concerned with the excessive flaring that resulted from the cladding moving out of place. Some fuses resulted in lateral wings forming on the fuse site, the sizes of which could be up to 1mm. These wings had to be sanded down for the fibers to fit in their final housing at Jefferson Lab, and it is of some concern that sanding removes the cladding about the fuse site and promotes light loss. A razor blade could be used to slice the wings off closer to the fuse site and minimize sanding, but my concern persisted. After consulting with Jim, I fused a few spare light guide lengths to each other and re-calibrated the fusing pressures. High lateral or vertical pressure both produced wings, but too low of a pressure would result in the fiber cores not fully fusing. Fuses with 86psi vertical pressure and 24psi lateral pressure resulted in the smallest wings possible while performing relatively well on strength tests. On average, a fuse at these pressures would break at about 1000g. After this adjustment, most fuses were right where we wanted them to be--fully fused with an unavoidable slight flaring at the corners.  

After this adjustment, most fuses were right where we wanted them to be--fully fused with an unavoidable slight flaring at the corners.  

The histogram below displays the distribution of widths in LGs and SciFis before and after fusing.

At one point, Christina and I took some of the older fibers to a dark room and shined a laser pointer through them to examine the light loss. Inspired by this, I looked at some of the heavily sanded fibers the same way and compared to the fuses at the reduced pressures. I noticed that the sanded fibers lost a lot of light at the fuse site while the new fuses lost almost none in this limited experiment.

[[File:Fiber Bulge Data.png|thumb|center|upright=2.0|LG, SciFi, and Fuse widths. Blue represents LG width, orange SciFi, and gray Fuse width.]]

 

 

Strength test breaking weights are reported in the table below.

{| class="wikitable"

{| class="wikitable"

| 1000g

| 1000g

|}

|}