LH Summer 2014

This summer I worked primarily on Fiber QA. My daily work journal can be found here. I'll summarize my tests here.

Results of Preliminary Fiber Tests

Before we could run through all bundles through QA tests, we had to calibrate and standardize the QA testing procedure. We found the following sources of error:

• Laser Intensity - if the laser is brighter, each fiber will result in a higher photon yield. Dr. Jones has compensated for this. We also found that the photon yields decrease as the pulser's 9V battery is drained.
• Temperature of the SiPM board - we found that as the fiber runs were done repeatedly without turning off the electronics and removing the board, the photon yield decreases. Automated runs resulted in variances between 3-5%

File:LH prelimfibertests temp.JPG

A histogram of the ratio of photon yields from each fiber compared to the average.

• Depth of the fibers in the chimney - We found that differences as small as 0.5 mm can have a minor affect on the photon yields.

A histogram of the ratio of photon yields from a fiber who was retracted 0.5 mm into the chimney compared to the a fiber flush with the chimney.

A histogram of the ratio of photon yields from a fiber who was retracted 1.0 mm into the chimney compared to the a fiber flush with the chimney