Wednesday, July 7, 2010

Day 3 at CERN : intellectual (physical) adventures continue

Today is the first day of the summer student lecture series and I was about 20 minutes late, no thanks to getting out late and then getting a little lost on my way over (though less loss than when I first biked home). The lecture was on heavy ion collisions and is the first of a tripartite series. For those back home interested in following these lectures, which are at a level that undergraduate students can understand, you can look it up here and use this page to access the previous year lectures. Lectures that have not passed will not be in display, but the ones that are over, you will sometimes get either the video or the pdf versions of the slides shown. Tomorrow onwards will be a continuation, though I am likely to attend selectively since I have my own work cut out for me.

Today, went to the CERN library and got out their annual reports. They are worth a study for anyone interested in understanding the sociology and historical developments of big science, as well as all the finances and politics involved in that. CERN is always a bustling place with tonnes of visitors and tourists (mainly Europeans but also others whose countries are involved with the LHC project) who would visit the main sites of the accelerators and other parts of the buildings that store old and some still useful parts from the older detectors and synchotrons.

Today was also the day in which I had a meeting with Rama Calaga, an accelerator physicist who is affiliated with Brookhaven but is now based at CERN to do some work there. He gave me an informal lecture on the history and development of particle physics, as well as lent me a book which I am and will be reading much of today and tomorrow. I asked him to clarify some of what may be the issues that led to the shutting down of the LHC for one year from 2008. The hypothesis pertaining to the leak that brought the LHC to a halt for a year, Calaga hypothesized that it is due to the fact that a interconnection between the dipoles and cryostats in one sector were not properly soldered in, thus lending to the production of an electrical arc at the seemingly barely visible gap to the naked eye when an electron current (beam) is injected through. This led to the heating of the helium in the cryostats to such a level that it ceases to be superconducting and thus begins to leak out through the cryostats. Dr Calaga also informed me of a program offered by Fermilab, a 2-week course (financial aid for that may be available) to train non accelarator physicists on the very basics of accelerator physics.

Having read a few pages of the first chapter of the book, An Introduction to the Physics of High Energy Accelerators, the physics involved is certainly not overly complicated an involved much understanding of advanced electromagnetic theory and charge physics. I will be able to say more after reading more through the book. While it is interesting to learn about the different uses of accelerator physics in free electron lasers, light sources, beta factories, ERL and even in medicine, it's the hadronic or leptonic collisions that are of interest to my work, and to the scientific ontology that I am studying. Collisions take place between bunches, hence packets of particles, rather than indidivual packets, and in terms of how measurements are an important aspect of experimental high energy physics that require precise tracking of beams as they go through the different sectors of the large hadron collider. So the ontology of measurements remain an important aspect of study in the ontolog of physics. Physicists working in accelerator and high energy physics are attempting to make sure that each aspect of the experiments are measured and covered (and this obsession could be seen from the performance-intensive analysis that always take place at the beginning of many of the papers produced by the experimental groups at CERN, and most probably elsewhere). Hence, how do we discuss this aspect in terms of the non-measurable, and whether that which is non-measurable can even be deemed to exist. Is that which is measurable already something that is solipsistic and cannot be seen as otherwise?

I may have to begin compiling some of the photographs and charts from around here for further examinations, and spend time trying to understand how the physicists (Whether grad student, postdocs, professors or research scientists) deal with the selection of various data, and the certification of quality.

Certification of quality is something which I will be learning more about tomorrow.

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