The energy spectrum of the single photon obtained using data from the LHCf experiment has turned out to be very different from that predicted by the theoretical models used until now to describe the interactions between very high-energy cosmic rays and the earth's atmosphere. The consequences of this discrepancy for cosmic ray studies could be significant. >>

Last week, Israel’s cabinet agreed that Israel could become a member of CERN, bringing CERN’s geographical enlargement one step closer. Council still has to discuss the timetable for accession. However, Israel’s associate membership, an essential prerequisite for membership, could begin this year. It’s a moment I’m looking forward to. >>

Scrubbing was completed on Wednesday 13 April. The run had seen over 1000 bunches per beam successfully circulating at 450 GeV. Measurements showed that electron cloud activity in the cold regions had been suppressed. A decrease of vacuum activity in the warm regions demonstrated that the cleaning had also achieved the required results there. As discussed in the last Bulletin, the scrubbing was performed with high intensity bunches with 50 nanosecond spacing. Given the potential luminosity performance with this spacing (more bunches, higher bunch intensity from the injectors) and in the light of the results of the scrubbing run, the decision was taken to continue the 2011 physics run with this bunch spacing. >>

Following several years of work, the construction of the Jardin Alpin – CERN tramline is almost complete, and the first tram is due to arrive at CERN on 30 April. Celebrations to mark the occasion will be held in Meyrin-Village and at CERN. >>

On 29 April, the Alpha Magnetic Spectrometer (AMS) will complete its long expedition to the International Space Station on board the space shuttle Endeavour. The Endeavour is set to lift off from NASA’s Kennedy Space Station at 15:47 EST (21:47 CET). >>

Pierluigi Campana begins his 3-year tenure as LHCb spokesperson this June. As the new voice for the collaboration, Campana will lead the experiment through what should prove to be a very exciting phase. >>

It's action stations at ISOLDE, the On-Line Isotope Mass Separator at CERN. The Laboratory is preparing to add a second laser ion source system to its arsenal. By alternating between two laser systems, the ISOLDE team will be able to switch from one type of beam to another in record time. >>

The 6th CERN–Latin American School of High-Energy Physics (CLASHEP) was held in Brazil from 23 March to 5 April. With its record-breaking attendance and strong international spirit, CLASHEP is yet another sign of the continent's growing particle physics community. >>

The IT and EN Departments are modernising the infrastructure of the Computer Centre to improve the conditions in which the equipment has to operate and to increase capacity. The construction work has already begun and is due to be completed in October 2012. >>

Since 2003, the International Labour Organization and the World Health Organization have been organising an annual event on 28 April called “World Day for Safety and Health at Work.” This year, CERN is taking part for the first time with campaigns organised by the Safety Unit of the BE Department and by the HSE Unit. >>

On Friday 15 April, CERN welcomed the first classes participating in the “Dans la peau d’un chercheur” project. >>

Since April 2009 CERN’s travelling exhibition has been touring through some of the Organization's Member States. After Italy and Denmark it has been on show since February at Austria’s Hartberg Ökopark, a very popular science museum situated some one hundred kilometres from Vienna. To coincide with the CERN exhibition, Austria’s scientific community has organised a series of events for the general public which have had marked success. The exhibition's next destination will be Portugal and preparations are already underway to ensure that it is another resounding success >>

Over the last couple of years, the Library has been expanding its collection of electronic books. The most popular titles are, of course, also bought as paper copies and are available for loan. >>