Digital signal processing debuts at CAS with resounding success

The CERN Accelerator School (CAS) and Uppsala University jointly organized a specialized school on a new theme this summer, with a course on digital signal processing, which took place in Sigtuna, Sweden, from 1 to 9 June.

The course was different this year in that the topic had never been treated by CAS, and unlike the usual specialized  courses, the structure comprised 32 hours of theoretical lectures in the mornings and a 16-hour "hands-on" course in the afternoons. The latter (well thought out by experts from CERN) had novel logistical implications for transporting computers and evaluation boards (DSPs and FPGAs) to Sigtuna, in central Sweden.

The principle of this new approach was well received by the accelerator community. A total of 97 participants representing 23 different nationalities attended the course, with 80% of the participants originating from the CERN member states. The positive feedback from the participants showed that the course was a resounding success, all the result of the expertise and enthusiasm of the lecturers who volunteered to take on this challenge. Considering the quality of the preparatory work, as well as the experience collected during the course, it is certainly conceivable that such a course will be considered again in the not-too-distant future, either in the framework of another CAS or similar schools.

In addition to specialized courses, CAS also organizes general accelerator physics schools at introductory or intermediate levels. More information about this and future courses, as well as examples of lecture notes from previous CERN accelerator schools and the corresponding proceedings, can be found at

U70 reaches 40th anniversary

On 14 October the U70, or the 70 GeV proton synchrotron at the Institute for High Energy Physics (IHEP) in Protvino, in south-western Russia, marks the 40th anniversary of its successful commissioning. The machine held the record for the top beam energy during the late 1960s and became the venue for work by many research, scientific and industrial institutions from around the former Soviet Union. It continues to form the core of experimental facilities of IHEP.

The schedule for launching the U70 in 1967 was tight. In its original configuration, the machine was fed with a beam injected from the 100 MeV Alvarez-type linac (I-100), for which commissioning had started as late as July the same year. On 17 September, the first beam circulated around the main ring and, on 12 October, the accelerator team achieved the important "transition crossing" at 8 GeV. At midnight on 14 October, the U70 accelerated a beam of protons up to an energy of 76 GeV. The U70 took up an important role in high-energy physics in the late 1960s and was the focus of successful co-operation with CERN on various accelerator systems (fast extraction, controls) and experimental facilities, such as the RF separator for the Mirabelle bubble chamber and other experimental equipment (CERN Courier November 2003 p3). Researchers carried out more than 50 experiments at the U70 in co-operation with physicists from CERN.

During the past four decades, the accelerator complex of IHEP has been subject to an extensive upgrade programme. A new injector came into operation (the 1.5 GeV, 16 Hz fast-cycling booster proton synchrotron U1.5) in 1985 to ease the Coulomb tune-shift limitation on beam intensity. This is fed by a unique 30 MeV proton linac (URAL30) based on conventional and drift-tube RF quadrupole (RFQ) accelerator concepts that were pioneered at IHEP.

Beam physicists and engineers at IHEP continue their efforts to keep the machine running and improve the quality of the proton beam that is delivered to users. The newly built 30 MeV DTL RFQ proton linac (URAL30M) is currently being pre-commissioned, and a programme to accelerate light ions (deuterium and carbon) through the re-conditioned I-100 to the booster, and eventually to the main ring of the U70, is taking place step-by-step.

The safety margin foreseen in the design and construction of the U70 is a legacy of the previous generations of accelerator experts, and is now a prerequisite for the continued operation of the U70 – the largest proton accelerator in Russia – for fundamental and applied research in the energy range of a few tens of giga-electron-volts.