Name : Pedro Luis Manuel Podesta Lerma

Name : Pedro Luis Manuel Podesta Lerma Period of time January 2006-February 2006 Experiment: CMS , CERN

Being the first the fist Helen fellow was quite a experience, no one knew for sure of all the administrative steps, but we learn together in the process.

First I started working with Nicholla Bachetta who is the supervisor of the Tracker detector of the CMS experiment; I helped in the preparation of a prototype of the detector for the magnet test. I also got familiarized with CERN and CMS.

In the following step I got involved in the Optical group of CMS under the supervision of Karl Gill. There I worked in the testing of the patch panel prototype and in testing some radiation damage to some optohybrids. My work consisted in work with the prototype in a realistic way to simulate the working conditions in the experiment, and design a possible cable procedure for it.

1. Digital Opto Hybrids (DOH) contamination

There was a white foam in the D0H. This generated some concerns about D0H performance over time. It was possible that with time the white foam can be expanded an then cause a malfunction of the laser.

So we did the following steps:

 Use 11 DOH  Temperature test D0H simulating conditions for the long term in the detector. For this we make thermal cycles of 20 an 48 hours.  Look for changes in electric test.  Look for changes by visual inspection.  Analyze chemical white foam composition.

The results we got were the following:

 NO significant changes in electric test, visual inspection or chemical composition.  Ready to be used in production.

2.- Patch Panel (PP1)

Here I developed a cabling procedure, and the design was slightly modified for the PP1 to go into production. See http://wwwclued0.fnal.gov/~podesta/PresentionOptoGrup.ppt for a best explanation.