Brendan M. KU News Service. Follow BrendanMLynch. Credit: CERN. Hometown news. Graduation and honor rolls. Subscribe to KU Today. Why KU. Powerful superconducting magnets will guide the counter-rotating beams to collision points around the accelerator. The collision energy of 14 trillion electron volts will be seven times greater than the world's present highest energy accelerator, the Tevatron at the Department of Energy's Fermilab.
The LHC's particle detectors, five stories high and weighing thousands of tons, will record the shower of subatomic particles from the collisions, which will occur at the rate of one billion per second. Scientists will then use computers to study the most interesting collisions in order to understand better the fundamental nature of matter and energy. The LHC will break new ground not only in physics research and technology but also in international collaboration, with scientists from every region of the world represented in the construction of the LHC accelerator and the major experiments.
Japan has already made a generous contribution of 8. CERN's business is pure research - studying Nature's tiniest building blocks, the fundamental particles, to find out how our world and the Universe work. The energy densities reached in head-on collisions of particles accelerated in CERN's machines approach those which may have prevailed immediately after the 'Big Bang', and are sufficient to create the elementary particles which populated the early universe.
Detectors, built around the collision points, record the brief existence of these particles, re-enacting moments in the evolution of the early universe. The LHC will be built from high powered superconducting magnets each 15 metres long. These magnets will hold two beams of protons rotating in opposite directions on a steady course around the ring, as superconducting accelerating cavities 'kick' them almost to the speed of light at energies of up to 14 TeV, higher than have ever been reached in accelerators.
When these proton beams collide, at fixed crossing points, their combined energy of motion will produce an intense micro-fireball which will shoot out hundreds of new particles. These flashes of energy will probe the interactions between the tiny quark constituents hidden deep inside the colliding protons and reveal how Nature works at the most fundamental levels. To build instruments capable of creating such extreme conditions and then analysing the results with extraordinary precision is a daunting challenge; it demands advances in many highly complex technologies.
The success of the LHC is directly linked to the ability of CERN's scientists, in close collaboration with industry, to push the limits of known technology way beyond today's frontiers. The LHC ring will contain some superconducting bending magnets. These magnets are among the most technologically challenging components of the machine. Superconductivity is a property that some materials acquire at very low temperatures, when their resistance to the passage of electrical current more or less disappears.
Under these conditions, large currents can flow easily through superconductors of small cross-section. This means that compact magnets can be built and operated for much lower cost than conventional 'warm' magnets made with copper or aluminium conductor. The only energy consumption of a superconducting magnet is that needed to refrigerate the conductor so that it remains superconducting. LHC bending magnets have twin apertures through which two vacuum chambers will be threaded to contain the circulating proton beams.
This unique and novel design allows the counter-rotating beams to be housed in a single cryogenic magnet assembly. For LHC protons to reach their collision energy of 14 TeV, the high technology superconducting electromagnets have to sustain a field of 8. To achieve this, the cable windings must be cooled to a temperature of 1. In the tests, the magnet, in its cryostat filled with superfluid helium, surpassed the LHC design field of 8. The magnet has since reached a field of 9.
In December of the same year, a full prototype section of the LHC was operated for the first time. The magnet string has since be put through strenuous testing, simulating over ten years of operation. The results have been extremely encouraging, confirming that the key technical choices made for the construction of the LHC magnets were correct. To study the collisions of the tiny quarks locked deep inside protons requires a microscope on a larger scale than ever before built.
But the microscope alone - the LHC itself - is not enough. Researchers using it have to have sharp eyesight. Their electronic 'eyes' come in the form of particle detectors. The LHC will have two general purpose detectors called ATLAS and CMS, each as high as a five-storey building, built like a Russian doll, with one module fitting snugly inside the other around the beam collision point at the centre.
Each module of the LHC's detectors, packed with state-of-the-art technology, is custom-built to do a special observation job before the particles fly outwards to the next layer. The interesting reactions when the hard quark grains in LHC's colliding protons clash head-on are extremely rare.
Most of the time they graze past each other with little disturbance, providing less interesting physics. To see enough interesting hard quark collisions, the physicists have to push for very high proton-proton collision rates. Collision rates are measured by what is called luminosity - the luminosity of a two-beam collider is the number of particles per second in one beam multiplied by the number of collisions per unit area in the other beam at the crossing point.
LHC aims to reach luminosities a hundred times higher than achieved in any existing experiment. To accomplish this, LHC's proton bunches, strung like beads on a chain 25 nanoseconds - 25 thousand millionths of a second - apart, will sweep through each other some 40 million times per second, each time producing about 20 interactions of one kind or another.
Many fields of research—such as those seeking to fundamentally understand the universe, generate new forms of energy, or unlock the secrets of subatomic particles—require large, technologically advanced instruments and facilities that necessitate decades of planning and billions of dollars of support.
In other fields, such as environmental and climate sciences, advanced sensory devices must be deployed and maintained in all corners of the world, requiring not only massive data storage and analysis capabilities, but also cooperation and coordination across countries and international waters. These megaprojects also often advance the frontiers of technology and expertise that can be applied to other fields, but they typically require both more funding than the United States is willing or able to provide alone and commitments of support over many years.
In the early s, philanthropies and private institutions were key players in supporting major investments in the U. The Carnegie Institution and the Rockefeller Foundation provided support for the construction and operation of U. A policy framework for significant federal support of research across a wide range of scientific and technical disciplines began in when Vannevar Bush published Science—The Endless Frontier , which argued that scientific progress was in the national interest and merited federal funding, an argument that directly contributed to the establishment of the National Science Foundation in Today, large-scale scientific facilities used by American scientists have become increasingly expensive and are most often built by the U.
The next generation of large-scale facilities required to advance scientific discovery and enable development of cutting-edge technologies, such as space-based observatories, ground-based accelerators and ground-based telescopes, advanced light sources, and deep-ocean research, will cost more than any single country is likely to provide without direct ties to economic or national security interests.
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