Monday 19 August 2013

ZIWA Off the Wall visit to CERN


Switzerland is home to one of the most exciting scientific establishments in the world, and on Friday 16 August 2013, twenty-nine ladies and one husband, members of ZIWA’s Off the Wall group, made this destination another voyage of discovery for the Zürich-based group. Travelling by first class train for the three-hour journey to Geneva, the ladies discussed their expectations and previous knowledge – more excitement than scientific expertise. This was soon to change on our arrival by tram at the CERN HQ in Meyrin outside Geneva.

Scientific background

What we were about to discover
CERN's worldwide users
First we were treated to an illuminating introduction from experimental physicist Marc Goulette, who gave a PowerPoint presentation of the history and function of the establishment. CERN, or the Conseil Europeen pour la Recherche Nucleaire, was founded in 1954, has currently 20 member states and comprises a multi-site international laboratory for experiments in particle physics. The headquarters is located near the French border in Switzerland, and the tunnel occupied by the Large Hadron Collider lies almost 100 metres underground and extends over 140 km. There are over 11,000 scientists and engineers working at CERN, which is financed and used by 110 countries. Its budget is CHF1.2 billion per annum, the equivalent of one cup of coffee per person, according to Marc.

The purpose of the research is to understand the nature of matter and the origins of the universe. Scientists collaborate in the analysis of data gathered during the process of particle collision. As well as PhD students, the centre hosts scientists from universities, hospitals, engineering and industry who all have a stake in the institution. The first particle collider, the LEP, was built in 1989 and by 1995 was able to uncover more understanding of anti-matter. Construction of the current Large Hadron Collider system began in 1999. The most recent experiment, the PS201, was set up in 2008 when the LHC started operating. In July 2012, the Higgs Boson particle, postulated 49 years earlier, was detected, and its properties have since then been examined. This particle is believed to have originated just after the universe was created with the Big Bang.

A major discovery in July 2012 - the Higgs Boson
The Large Hadron Collider is the world’s largest particle accelerator and consists of a 27 kilometre tunnel with a ring of superconducting magnets which focus the particle beam as it whizzes round the tunnel. Particle collisions are created in 4 different locations deep under the ground in Switzerland and France. The collisions cause different particles to be released, and the surrounding detector tubes enable different types of particle to be sensed and analysed. Such particles include quarks, leptons, bosons, gluons, muons and fermions. There are a number of projects taking place at the moment, but the collider is not in operation today while it is being updated, and the data collected over the past years is now being analysed.

Into the underground realm of the LHC

Over the border

After this quick introduction to this complex topic, we were taken by bus over the border into France, to see the Large Hadron Collider. At the centre at Cessy, we split into three groups to learn about the geography and physics of the different installations. We first saw a life-size image of a cross-section of the Compact Muon Solenoid (CMS) which focusses the proton beams. The huge magnetic tube is located 90 metres below the earth in hard rock, and operates at a temperature of -269 degrees C, close to absolute zero. The solenoid consists of different layers which detect different types of particle by means of magnetic superconductors and leaded silicon crystals. At the push of a button, the source protons or lead ions start to fly round the ring in opposite directions. Collisions are induced at four different spots under the ground over periods of 15 hours, and the detectors run constantly. The scientists then try to recreate the pattern of interactions in order to understand the phenomena taking place.

The cross-section of the solenoid

100 metres underground


Each section detects different phenomena
After waiting patiently for our turn, we passed through the airlock door and took the lift down to the rocky interior. As the LHC was not in operation, we were able to see more of its cross-section. Engineers used bicycles to travel along the tunnel during construction, and a mountaineer is employed to fix faults on the huge surface of the solenoid. But any small faults inside the collider cannot be fixed. If a small electrical fire should break out, the charge is directed safely to the earth’s surface, and a quench system operates in case of a major incident – thankfully very rare.

After this fascinating glimpse into the realm of state-of-the-art nuclear physics deep in the French and Swiss countryside, we retraced our steps back to base and returned by tram and train to Zürich. Thanks to Katrin Gygax and to the CERN scientists and guides for making this unforgettable day possible.


Julia Newton. 19 August 2013.

Friday 2 August 2013

Restaurant of the Month - July 2013

Wirtschaft Neumarkt, Neumarkt 5, 8001 Zurich.

http://wirtschaft-neumarkt.ch/

Zurich Summer 2013 has been exceptional after such a long, hard winter. So the ZIWA Dining Around the World group plans to take every opportunity to eat outdoors. This time we chose a small restaurant in the Altstadt with a surprisingly large terrace at the rear. Our table for 12 was under a shady pergola at the back. It was an occasion for relaxing, chatting and enjoying the food.

There was a good choice of menus at lunchtime last Tuesday - classic Swiss dishes with good local ingredients. We could opt for the menu of the day or a selection of seasonal summer dishes. To start, most people went for the fennel salad but you could also choose a delicious cauliflower soup with plenty of fresh bread. The main courses included cod on a bed of beans, tomato sauce and chunky vegetables, chicken with rosemary butter, polenta and ratatouille, shrimp risotto with cherry tomatoes, pork cutlet with spaetzli, or the pasta of the week. The lunch menus cost from CHF 28 to CHF 35 including soup or salad. Drinks and coffee were extra, as usual.

This restaurant is a popular choice when the terrace is open, and all the tables were full this week. Inside, there is limited space so it's best to book. The restaurant is next door to the Theater Neumark and is popular with theatre goers, but you need to book ahead. Dinner is still reasonably priced at under CHF 40. There is an interesting choice of Swiss wines on the wine list, and the food is supplied locally where possible.

So for a quiet venue in the back of the old town (tram 3 to Neumarkt and then 3 minutes' walk) with outdoor seating in summer, give this restaurant a try!