The European Organisation of Nuclear Research (CERN) is the place to be for particle physics, and with 45 participants from all around the world the annual IAPS visit took place from the 20th to the 23rd of April 2015. As one of the volunteers organising the trip, and de-facto leader during the trip I would like to both summarise the trip and share some of my impressions; for the benefit of all those who where there, and for those who were not - there is always another chance next year.

A view of the Synchrocyclotron at CERN A view of the Synchrocyclotron at CERN. Picture by Max Lisogorski

First of all, the trip was a full success. The participants were of course fantastic, and the programme organised for us by CERN was amazing - even as someone who was there a few times before the visit was full of nice surprises.

During the whole trip we had absolutely perfect weather - sunny enough to get me thoroughly sunburnt. Every now and again Mont Blanc was visible on the horizon. The weather allowed very pleasant nightly sightseeing in Geneva, with many participants enjoying the nice parks. Nightly, as the tight physics schedule meant spending most of the first two days at CERN. In addition we had the rare opportunity to spectate a CERN amateur football game with a BBQ in the evening of our first day. A social evening of Chess, Checkers and card games in Geneva’s main park also helped ensure that the social part of the trip did not fall short.

The physics highlights were - as probably expected - the visits to CMS, AMS, the SM18 and the Synchrocyclotron. Due to LHC run 2 the CMS experimental cavern was sadly off limits, but the CMS service cavern and overground facilities where interesting in their own right. At its rival, ATLAS, we only had access to the visitor centre, and a very nice view into the ATLAS control centre. CMS and ATLAS are of course the two competing general purpose detectors at CERN, responsible among other things for the discovery of the Standard Model Higgs Boson in 2012.

AMS2 was again unfortunately off limits, as it is inconveniently attached to the ISS. However, we visited the AMS control centre and found out many interesting things about the only general purpose detector in space - everything is better in space. At SM18, the Magnet Test Facility, we were treated to a up close encounter with prototype LHC magnets, allowing detailed insight into the CERN accelerator chain, which was further explained at the tour of the CERN control centre.

As a great contrast we also saw an experiment from a different century: the Synchrocyclotron. One of the first experiments at CERN it is immensely important as the machine that helped discover the V-A nature of the weak interaction. Nowadays it has been converted to a very modern exhibition about the beginnings of CERN and includes a spectacular light-show (as you can see in the pictures).

In addition to the tours we enjoyed several very interesting talks: An Introduction to Particle Physics by ATLAS physicist Emma Kuwertz ensured that everybody would leave Geneva with a good understanding of what they had seen, and what it meant in the big picture of fundamental physics. Manjit Dosanjh, the only Biologist at CERN and CERN Life Science Advisor, gave a fascinating presentation on the medical applications of particle physics, a topic most participants found very interesting – even many of those who usually prefer fundamental research to applications.

Finally a Question and Answer session with ATLAS physicist Michael Hauschild was the final event of the physics programme. This session took much longer than planned, as the participants came up with question after question, and the entertaining and enlightening answers kept coming.

To roundup the trip, we also visited the United Nations in Geneva, seeing both the historic Palais des Nations and the more modern annex which hosts the Human Rights Council and many other UN meetings. Visiting CERN and the UN shows quite strikingly what amazing things humans can achieve when they manage to work together. To contrast the cutting edge research at CERN we also visited the beautiful History of Science Museum in Geneva, which is situated just off the Lac Leman. In the small but fascinating museum we could see scientific instruments dating back centuries, including ancient Egyptian steam vehicles, one of the first batteries and many more fascinating artefacts.

On a personal note, the trip was certainly a weird one, as I got to know IAPS as a participant in the 2013 iaps2CERN tour. Having switched sides now, I can appreciate the effort that goes into such a trip, and hope that everyone enjoyed the trip as much as I enjoyed my first visit to CERN. Organising this trip was a lot of work and very stressful - especially when simultaneously working on a master thesis - but also a lot of fun. I highly recommend that you get involved with IAPS, if you are not already. Maybe you could help with the existing trips, or if you have an idea why not try to start up a new IAPS excursion?

The Synchrocyclotron in a light-show The Synchrocyclotron in a light-show. Picture by Thamires Vieira

The group in front of the ATLAS control centre building at CERN The group in front of the ATLAS control centre building at CERN.