CERN Accelerating science

Crossing the borders on the Y bus

Andreas Nørgård Larsen 13th Aug 2013
August 2013
In the autumn 2011 I won a physics competition among the students at Copenhagen University. The award was a four-day tour to Norway at a particle physics conference, nicely combined with skiing vacation. The tour was in January during the second year of my studies. 
 
The winter came and so did the conference. I was very excited. After four days in Norway I returned with a broken arm and a tremendous amount of questions. Who is this SUSY they are all talking about. And what about tau, ALICE, meson, hadron, muon, antiquarks and all the other buss words. I wasn't much cleverer and my physical condition was clearly worse than before. However, I had become richer in one aspect: curiosity. And I had met guys who had been to the CERN summer school and recommended it warmly. 
 
Eighteen months later I found myself crossing the borders to France - on the Y bus from the airport, but in the wrong direction. The following weeks I have crossed the boarder at least twice a day back and forth my office in France. A humble office, that is definitely not what you would expect from CERN - the worlds largest and most impressive laboratory. And many other borders have been crossed since. I have crossed the boarder into one of the physicians' "holy places" and seen the impressive CMS. I have crossed the border of overwhelmingly many cultures. The daily meeting with people from all over the world is an experience I will never forget. 
 

I am in a group working with the detectors in CMS. Some are doing simulations and some are doing direct hardware measurements. I am doing some simulations on a detector - Medipix - that are to be installed in 32 examples in the CMS cavern during the long shutdown. The Medipix detector can contribute to the CMS by online neutron detection. Nobody is really interested in neutrons nowadays - they had their moment of glory back in the 20s and 30s. But there are (at least) two good reasons to measure them:

1) Neutrons can cause so-called single event upset (SEU) in the electronic devices, thereby disturbing the signal (changing zeros to ones, and vice versa). So it is very good to know where not to place many electronic devices. Furthermore, this knowledge can give us an idea if it is necessary to shield certain electric devices from radiation.

2) Measurement on the neutron radiation can help correcting the simulations that are used to make predictions of the lifetime of interesting and exotic particles.

I had not done simulation before and the programme (FLUKA/flair) I use is all new to me, so I have had a lot of challenges and small frustrations here at CERN. However, I am here to learn something new - and I definitely do! 

I think this project will be the first, but definitely not the last on detector simulations and installations - I like being part of such a complicated and big project as the LHC is, and the huge and still very precise detectors really fascinate me.

To be a part of this humungous machinery of people, detectors, technology, administration, cultures, knowledge, data and progression is really fantastic. And it is a great bonus to fill the weekends with tours to the steep Jura mountains and enjoy the breathtaking view, to Geneva and jump into the refreshing water, to the jazz festival in Montreux. And with 300 summer students, there  always at least one who wants to join. 
 

The first picture "bade" (danish for "to bath") is from Geneva Lake. I am not in the picture since I was behind the camera at that very moment. 
 

 
The second picture is from - da-da-daa - CMS! I am together with Sri (Srinidhi Bheesette) my new friend and colleague from India - also a summer student.