European Particle Physics Laboratory Research Articles

Mutually benefiting joint innovation process between industry and big-science

This longitudinal study is based on nine in-depth case studies carried out over the past 9 years, entailing observation of and participation in the actual innovation processes taking place at the interface of big-science-industry cooperation. The resulting mutually benefiting innovation model integrates industrial and big-science R&D at moments when they best catalyse technological innovation processes by matching specific needs from both sides and facilitating their joint efforts during the cooperation. The big-science centre being CERN 2 2 CERN, the European Laboratory for Particle Physics, has its headquarters in Geneva. At present, its Member States are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, The Netherlands, Norway, Poland, Portugal, the Slovak Republic, Spain, Sweden, Switzerland and the United Kingdom. The European Commission, India, Israel, Japan, the Russian Federation, Turkey, UNESCO and the USA have observer status. with its multiple skills, diverse assets and technology validation practices generate, when needs from both sides are clearly defined and well coupled, a most fertile ground to enable and boost industrial innovation. The big-science centre benefits from the cooperation through access to cutting edge technologies at reasonable cost and through manufacturing prospects which both bring optimal performance per cost ratio in instrument design and production. At the same time, it generates meaningful social practice and input into industrial innovation and new business creation. A successful matching process includes: industrial scouting and scanning to find applicable new technologies in the industry; assessment of related business development needs in order to find and create the right motivations for mutually benefiting cooperation; identification of functional specifications for big-science instruments; and an active match-making of needs, motivations and people as well as timing. The research documented in this report complements previous research efforts by providing detailed recommendations to all parties present in big-science collaborations, namely the big-science centres, member state policy-makers and industry experts and managers.

FE-I2: a front-end readout chip designed in a commercial 0.25-/spl mu/m process for the ATLAS pixel detector at LHC

A new front-end chip (FE-I2) has been developed for the ATLAS pixel detector at the future Large Hadron Collider (LHC) accelerator facility of the European Laboratory for Particle Physics (CERN). This chip has been submitted in a commercial 0.25-/spl mu/m CMOS process using special layout techniques for radiation tolerance. It comprises 2880 pixels arranged into 18 columns of 160 channels. Each pixel element of dimension 50 /spl mu/m /spl times/ 400 /spl mu/m is composed of a charge- sensitive amplifier followed by a fast discriminator with a detection threshold adjustable within a range of 0-6000 electrons and slow control logic incorporating a wired-hit-Or, preamplifier-kill, readout mask, and automatic threshold tuning circuitry. There are two single-event-upset (SEU)-tolerant DACs for reducing threshold (7-b) and recovery-time (3-b) mismatches from pixel to pixel along with digital hit emulation and a differential readout circuit aimed at transporting time-stamped data from each pixel to buffers at the bottom of the chip. In comparison to previous generations of the ATLAS pixel chip, FE-I2 incorporates many new features such as embedded "smart" decoupling capacitances, long-term overvoltage protection, linear regulators, a capacitance calibration charge-pump circuit, a power-on reset, and a leakage current monitoring circuit. Its predecessor (FE-I1) has been demonstrated to operate correctly after ionizing radiation doses exceeding 50 Mrad (SiO/sub 2/). Special techniques employed for digital pick-up reduction are also described.

Advances in silicon detectors for particle tracking in extreme radiation environments

The LHC (Large Hadron Collider) is currently under construction at CERN, the European Laboratory for Particle Physics based in Geneva. The experiments at this accelerator will use substantial numbers of silicon detectors. These are close to the interaction point and will be exposed to very high fluences ( up to 1015particlescm−2) during their operating life. Such detectors are crucial to the disentanglement of important decay events and it is vital to guarantee a homogeneous reliable performance during their operation. Parameters like the charge collection efficiency (CCE) and response time will be discussed. Limitations of present technologies will be analysed and future strategies explored. Results obtained using alternative detector designs, such as 3D geometry, material engineering by oxygen diffusion and unconventional operational conditions are surveyed.

Organizational emergence in networked collaboration

AbstractResearch on complex adaptive systems has generated several conceptual parables to explain systems with emergent behaviour. One prominent use for terms such as self‐organization, evolutionary trajectories, co‐evolution and punctuated equilibrium has been in understanding human organizations. In such systems, emergent behaviour is demonstrated in novel structures, processes and spin‐offs that cannot be explained just by studying single components of the organization and the intelligence embedded in them. Instead of solely exploiting the qualitative explanatory power of the evolutionary concepts, this paper focuses also on quantitative methods to track emergent behaviour in a globally distributed, constantly fluctuating and highly networked project organization. The underlying case is that of CERN (CERN, the European Laboratory for Particle Physics, has its headquarters in Geneva. At present, its Member States are Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Netherlands, Norway, Poland, Portugal, the Slovak Republic, Spain, Sweden, Switzerland and the United Kingdom. Israel, the Russian Federation, Turkey, Yugoslavia (status suspended after the UN embargo, June 1992), the European Commission and UNESCO have observer status.) and its decade long accelerator project, which strongly relies on electronic communication and networking to achieve its major objectives due to be accomplished by the year 2006. By using time series and self‐organizing maps to analyse the global interaction among project groups and individuals the paper provides new insight to the understanding of emergent behaviour in human organizations. The key result of the study concerns the rigid deep structure of each case organization that seems to remain intact for the duration of the whole project. Copyright © 2002 John Wiley & Sons, Ltd.

Analog front-end cell designed in a commercial 0.25 /spl mu/m process for the ATLAS pixel detector at LHC

A new analog pixel front-end cell has been developed for the ATLAS detector at the future Large Hadron Collider (LHC) at the European Laboratory for Particle Physics (CERN). This analog cell has been submitted in two commercial 0.25 /spl mu/m CMOS processes (in an analog test chip format), using special layout techniques for radiation hardness purposes. It is composed of two cascaded amplifiers followed by a fast discriminator featuring a detection threshold within the range of 1000 to 10000 electrons. The first preamplifier has the principal role of providing a large bandwidth, low input impedance, and fast rise time in order to enhance the time-walk and crosstalk performance, whereas the second fully differential amplifier is aimed at delivering a sufficiently high-voltage gain for optimum comparison. A new do feedback concept renders the cell tolerant of sensor leakage current up to 300 nA and provides monitoring of this current. Two 5-bit digital-to-analog converters tolerant to single-event upset have been implemented for threshold and recovery-time pixel-to-pixel matching purposes. Special attention has been paid to the power-supply rejection ratio to minimize sensitivity to pickup. The complete cell dissipates 30 /spl mu/W, occupies an area of 50/spl times/90 /spl mu/m/sup 2/ and is operated with a single 1.6-V power supply. Measurements of two test chips are presented.

Gamma-ray sensitivity of a thin gap chamber

The Large Hadron Collider (LHC) at the European Laboratory for Particle Physics (CERN) is expected to operate at a luminosity of 10 34 cm −2 s −1 resulting in a rather large background radiation in the experimental hall. A Thin Gap Chamber (TGC) will be used for forward muon triggering in the ATLAS experiment. According to a simulation, the main source of background around the TGC in the experimental hall will be neutrons and photons. In this report, we describe measurement of the sensitivity of the TGC to γ-rays. The measurements were made with γ-rays from radioactive sources with energies between 20 keV and 1.8 MeV . The sensitivity was found to be less than 1%, which is in good agreement with the EGS4-based simulator.

The Middle East Synchrotron Facility can bring Regional Cooperation

AbstractOver three years ago, Germany decided to gift the BESSY‐I, a 800MeV synchrotron, fully functioning since 1982 in Berlin, to the region of Middle East. The Middle East Synchrotron better known by the acronym SESAME (Synchrotron‐light for Experimental Science and Applications in the Middle East) will be the upgraded reincarnation of BESSY‐I. SESAME, the first synchrotron in the Middle East, is envisioned as a seed for a regional international research center, open to scientists in the region and beyond. The founders of the SESAME Project see a facility similar in purpose to the European Laboratory for Particle Physics (CERN) in Geneva, which brought together numerous scientists from countries that had fought each other during the two World Wars. Scientific collaboration beyond the national boundaries has been a force for peace in the cold war. An account of events leading to these very significant developments is presented.

The data-acquisition system for the CMS tracker beam tests

This paper describes the conception and the development of a real-time data-acquisition system for prototype detectors of the being designed for the compact muon solenoid (CMS) experiment at the Large Hadron Collider of CERN, European Laboratory for Particle Physics, Geneva, Switzerland. The rationale for the development of a dedicated data-acquisition system was the need to perform two fundamental beam tests (the Barrel 1 and Forward 1), with large-scale prototypes of the detectors planned as the baseline design. The number of readout channels, the complexity of the readout electronics, and the stringent requirements of the milestone tests mandated that a thorough understanding of the issues related to the physics of the detectors themselves be coupled with the application of leading-edge electronic and software engineering technologies. The implementation described in this paper is based on a distributed architecture. An event builder CPU handles the two main tasks of synchronizing a variable number of front-end processors and formatting the data in preparation for the transfer to a dedicated high-performance storage system, while the front-end processors handle the hardware and the real-time readout. Additional workstations are used to decouple the actual task of transferring the data files and monitoring the detector performance on-line from the readout farm. The system has been successfully operated during the two aforementioned Milestone tests, allowing the CMS collaboration to pass them, with the simultaneous readout of up to 40000 detector channels. The results of the two Milestones have led to the compilation of the Tracker Technical Design Report. Subsequently, the same readout system has been used for a number of other beam tests, and it has formed the basis for the development of further, more advanced data-acquisition systems for the new readout electronic of the CMS Tracker.

The Final Tally Leaves LEP a Probable Loser

Physicists at CERN, the European particle physics laboratory near Geneva, are making a last-ditch appeal to postpone demolition of the lab's Large Electron-Positron (LEP) collider. Scheduled to be scrapped in September to make room for a new device, the Large Hadron Collider, LEP was granted a 1-month stay of execution so physicists could continue experiments hinting at evidence for the Higgs boson--a theoretical particle that physicists have coveted for decades. On 8 November, CERN's director-general turned down a further extension, but the executive committee of the lab's staff association blasted the decision, saying that the case against LEP had not been made clearly enough.

CERN Link Breathes Life Into Russian Physics

Without fanfare, 600 Russian scientists here at CERN, the European particle physics laboratory, are playing key roles in building the Large Hadron Collider (LHC), a machine that will explore fundamental questions such as why particles have mass, as well as search for exotic new particles whose existence would confirm supersymmetry, a popular theory that aims to unify the four forces of nature. In fact, even though Russia is not one of CERN's 20 member states, most top high-energy physicists in Russia are working on the LHC. Some say their work could prove the salvation of high-energy physics back home.

Bulgarians Sue CERN for Leniency

In cash-strapped Bulgaria, scientists are wondering whether a ticket for a front-row seat in high-energy physics is worth the price: Membership dues in CERN, the European particle physics lab, nearly equal the country's entire budget for competitive research grants. Faced with that grim statistic and a plea for leniency from Bulgaria's government, CERN's governing council is considering slashing the country's membership dues for the next 2 years.

CERN Gives Higgs Hunters Extra Month to Collect Data

After 11 years of banging electrons and positrons together at higher energies than any other machine in the world, CERN, the European laboratory for particle physics, had decided to shut down the Large Electron-Positron collider (LEP) and install a new machine, the Large Hadron Collider (LHC), in its 27-kilometer tunnel. In 2005, the LHC will start bashing protons together at even higher energies. But tantalizing hints of a long-sought fundamental particle have forced CERN managers to grant LEP a month's reprieve.

Physicists haunted by hints of Higgs boson

Munich Physicists at the European Laboratory for Particle Physics (CERN) are locked in debate over whether to keep their largest accelerator running to look for evidence of the Higgs boson.

Hunt for Higgs particle wins time for CERN collider

Munich New analysis of particle collisions at the European Laboratory for Particle Physics in Geneva have increased physicists' hopes that they have witnessed evidence of the Higgs boson.

CERN considers chasing up hints of Higgs boson. European Laboratory for Particle Physics

Geneva Physicists at CERN were locked in a dilemma earlier this week: whether or not to gamble SFr30 million (US$17 million) pursuing the possible first viewing of a Higgs boson.

Israel debates raising commitment to CERN. European Laboratory for Particle Physics

Jerusalem Israel's science ministry is considering whether to apply to become a full member of the European Laboratory for Particle Physics.

Cryogenics for the Large Hadron Collider

The Large Hadron Collider (LHC), a 26.7 km circumference superconducting accelerator equipped with high-field magnets operating in superfluid helium below 1.9 K, has now fully entered construction at CERN, the European Laboratory for Particle Physics. The heart of the LHC cryogenic system is the quasi-isothermal magnet cooling scheme, in which flowing two-phase saturated superfluid helium removes the heat load from the 36000 ton cold mass, immersed in some 400 m/sup 3/ static pressurised superfluid helium. The LHC also makes use of supercritical helium for nonisothermal cooling of the beam screens which intercept most of the dynamic heat loads at higher temperature. Although not used in normal operation, liquid nitrogen will provide the source of refrigeration for precooling the machine. Refrigeration for the LHC is produced in eight large refrigerators, each with an equivalent capacity of about 18 kW at 4.5 K, completed by 1.8 K refrigeration units making use of several stages of hydrodynamic cold compressors. The cryogenic fluids are distributed to the cryomagnet strings by a compound cryogenic distribution line circling the tunnel. Procurement contracts for the major components of the LHC cryogenic system have been adjudicated to industry, and their progress will be briefly reported. Besides construction proper, the study and development of cryogenics for the LHC has resulted in salient advances in several fields of cryogenic engineering, which we shall also review.

The magnets for the LHC experiments

The Large Hadron Collider (LHC) presently under construction at the European Laboratory for Particle Physics (CERN) will provide proton-proton collisions at the 14 TeV level. Each of the four approved detectors (ALICE, ATLAS, CMS, and LHCb) to be installed at the interaction points of this machine relies on a sophisticated magnet system for separation and momentum measurements of the charged particles. The magnets are being designed, manufactured, tested and installed under the technical and financial responsibility of the experiment collaborations, but must satisfy constraints imposed by the laboratory, regarding in particular the cryogenics, powering, controls, and safety. The delivery and assembly schedules are also highly constrained by the requirement to have the magnet systems fully installed before the projected commissioning of the accelerator in 2005. The report compares the salient features of these magnet systems, and of their integration into the CERN environment.

CERN claims first experimental creation of quark-gluon plasma. European Laboratory for Particle Physics

Munich The European Laboratory for Particle Physics (CERN) is planning to announce today (10 February) that it has “compelling evidence” that it has successfully created the quark–gluon state of matter predicted to have existed shortly after the Big Bang.

Fourth Intercomparison of Personal Dosemeters used in US Department of Energy Accelerator Facilities

Personal neutron dosemeters from seven US Department of Energy (DOE) laboratories were mailed to the European Laboratory for Particle Physics (CERN) and irradiated using the well-characterised CERN reference radiation facility (CERF). Neutron dose equivalents determined using the DOE personal dosemeters have been compared to the reference dose equivalent as determined using a tissue-equivalent proportional counter (TEPC). In the 0.5 to 5 mSv dose equivalent range, the comparison of results suggests that the neutron personal dosemeters in use at DOE facilities are capable of estimating dose equivalents for high energy neutrons to within a factor of at least 2 or 3. If a field-specific calibration factor is used to correct the dose equivalent responses, the agreement with the reference dose equivalent for these dosemeters can be improved to better than about 25 to 65%. Suggestions for future intercomparison studies and methods of improving personal dosimetry at accelerator facilities are discussed.