From the July/August 1973 issue

Storm hits CERN

Late in the afternoon of 12 June, a cloudburst lasting an abnormally long time (over an hour) swept down on CERN and left behind flood damage amounting to millions of Swiss francs. Preceded by a violent wind of nearly 50 miles [80 km] an hour, the storm began with hail that fell for 15 minutes. Drains, choked with hailstones and leaves, were unable to cope with the subsequent torrent of rain. Hardly a building or installation, surface or underground, went unscathed, but three areas were hit very hard: installations of the Nuclear Physics Division, Track Chambers Division and Health Physics Group.

In NP Division, water and mud inundated Hall 1-1 of the Intersecting Storage Rings to a depth of a metre and the delicate equipment there – mainly electronic counters and spark chambers – can be considered a write-off. In the basement of Laboratory 3, spark chambers, vacuum pumps, detectors, recorders and stabilized power supplies were for the most part destroyed.

A wave of water passing down the road from the ISR penetrated the electricity substation and by underground tunnels reached the basements of Laboratory 13, where there was a large quantity of apparatus belonging to TC Division – counters, scalers, power supplies, spares for measurement tables, etc. Many reels of unexposed film were completely submerged, together with 400 km of exposed film.

The 2 m hydrogen bubble chamber was the scene of much activity when water was seen infiltrating under the chamber building in the tunnels housing the 10 kA power supplies and the power, monitoring and safety lines of the entire installation. The refrigeration plant had to be shut down and it was decided to evacuate the liquid hydrogen from the chamber.

The most serious damage in the Health Physics Group building was the complete destruction of the low-level counting laboratory. The laboratory is in the basement to reduce the influence of environmental radiation and its specialised equipment is a total write-off.

• Compiled from texts on pp217–219.

Vacation courses

During the season when many CERN employees are off on holiday, vacation students have arrived to follow a two to four month course.

At the end of every year, circulars on the courses [which began in 1962] are sent by the Fellows and Associates Service to the universities and technical colleges in all the Member States. Students reading physics, electrical and electronic engineering, mathematics and information science are invited to submit applications before the following March.

This year there were some 350 applicants, of whom 148 were invited to follow the courses. They are distributed over the various scientific and technical divisions – joining groups working on experimental and applied physics, data handling, accelerators, technical services or health physics. As well as taking part in the daily work of the groups, the students are offered a series of lectures on elementary particle physics, accelerators, detectors and computer science, through which they can become familiar with the various facets of particle physics research.

• Compiled from texts on p219.

Compiler’s Note

Climate change? Extreme weather events – destructive hailstorms and increasingly high temperatures – are a regular feature of summer in western Switzerland. The highest temperature ever reached north of the Swiss Alps, 39.7 °C, was recorded in Geneva in July 2015.

Wild weather notwithstanding, the number of applications for CERN’s hugely popular summer student programme continues to grow. It is presently around 1000, with some 150 candidates selected each year. In 1998, the programme was extended to include high-school teachers, and for the past 15 years or so, non-Member-State participants have joined their European colleagues, thanks to complementary funding. Many a successful career in physics followed a summer as a student at CERN.

About the author

Compiled by Peggie Rimmer.