When beams with trillions of particles go zipping around at near light speed, there's bound to be some chaos. Limiting that chaos in particle colliders is crucial for the groundbreaking results such experiments are designed to deliver.
In a special focus issue of the journal Chaos, from AIP Publishing, a physicist at the European Organization for Nuclear Research (CERN) details an important method of detecting and correcting unwanted chaotic behavior in particle colliders. The method is helping accelerator physicists design high-performing, cost-efficient accelerators in an era of constrained science budgets.
The aim of the focus issue is to review, comprehensively, the theory and implementation of existing methods of chaos detection and predictability -- as well as to report recent applications of these techniques to different scientific fields. The Focus Issue: Chaos Detection Methods and Predictability is collection of 12 papers representing the wide range of applications, spanning mathematics, physics, astronomy, particle accelerator physics, meteorology and medical research.
Chaos has long bedeviled physicists trying to describe the precise motions of interacting objects. The French mathematician Henri Poincaré discovered the essence of the phenomenon in the late 1800s when he attempted (unsuccessfully) to predict precisely the motions of the solar system's planets. The same chaotic behavior appears in the crowds of particles traveling inside accelerators like CERN's Large Hadron Collider.
In these machines, powerful electric and magnetic fields accelerate and guide beams containing trillions of particles. Ideally all particles would travel in orderly orbits around the rings into which they are injected. But in reality, some of the particles spread out around the ring's center, where they can become chaotic due to their mutual interactions and to defects in the magnetic fields that guide them. Particles that get kicked out of stable orbit can then crash into the collider's ultra-cold superconducting magnets. If this happens too often, the magnets heat up and the particle beams have to stop, which compromises experiments and creates costly delays.
From previous work in astronomy, Yannis Papaphilippou, a physicist at CERN, knew of a method called "frequency map analysis" that relates the frequencies at which objects oscillate to their chaotic behavior. Over the course of more than a decade, Papaphilippou and his colleagues applied the method to visualize those same frequencies in simulations of particle beams in accelerators. Using such simulations, physicists can design colliders to avoid chaotic beam interactions and keep particles on track.
The method has already born fruit. By modeling the extent to which tiny defects in the LHC's superconducting magnets cause protons traveling in the collider's rings to behave chaotically, Papaphilippou and his colleagues helped magnet builders design and produce these magnets within strict tolerance limits. The researchers also showed that only half as many correcting magnets were needed as was originally thought.
These findings substantially reduced the collider's cost and, along with many other efforts, helped streamline the search for the Higgs boson, Papaphilippou said. "All the big discoveries that we've had in the LHC…would have been hampered if there was not a very detailed design and evaluation of the nonlinear effects and their correction." Frequency map analysis has also helped scientists optimize the Spallation Neutron Source in Oak Ridge, Tenn. As a result of this optimization, the machine set a world record last year for power delivery.
As physicists design new accelerators, Papaphilippou predicts they will use frequency map analysis to achieve high performance at reasonable cost. The Particle Physics Project Prioritization Panel (P5), which advises the U.S. government, identified collider cost as a major concern in a recent report on the future of particle physics.
"Studying these [chaotic] effects from scratch can be a very-cost effective way to build and design these accelerators," Papaphilippou said.
The article, "Detecting chaos in particle accelerators through the frequency map analysis method," is authored by Yannis Papaphilippou. It will appear in the journal Chaos on June 30, 2014. After that date, it will be available at: http://scitation.aip.org/content/aip/journal/chaos/24/2/10.1063/1.4884495
ABOUT THE JOURNAL
Chaos: An Interdisciplinary Journal of Nonlinear Science is devoted to increasing the understanding of nonlinear phenomena and describing the manifestations in a manner comprehensible to researchers from a broad spectrum of disciplines. See: http://chaos.aip.org/
Jason Socrates Bardi | Eurek Alert!
Studying fundamental particles in materials
17.01.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie
Seeing the quantum future... literally
16.01.2017 | University of Sydney
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction