Download or read book Measurements of Beam Halo Diffusion and Population Density in the Tevatron and in the Large Hadron Collider written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Halo dynamics influences global accelerator performance: beam lifetimes, emittance growth, dynamic aperture, and collimation efficiency. Halo monitoring and control are also critical for the operation of high-power machines. For instance, in the high-luminosity upgrade of the LHC, the energy stored in the beam tails may reach several megajoules. Fast losses can result in superconducting magnet quenches, magnet damage, or even collimator deformation. The need arises to measure the beam halo and to remove it at controllable rates. In the Tevatron and in the LHC, halo population densities and diffusivities were measured with collimator scans by observing the time evolution of losses following small inward or outward collimator steps, under different experimental conditions: with single beams and in collision, and, in the case of the Tevatron, with a hollow electron lens acting on a subset of bunches. After the LHC resumes operations, it is planned to compare measured diffusivities with the known strength of transverse damper excitations. New proposals for nondestructive halo population density measurements are also briefly discussed.
Download or read book Measurements of Transverse Beam Halo Diffusion Rates in the LHC With Collimator Scans written by and published by . This book was released on 2012 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurements of Transverse Beam Diffusion Rates in the Fermilab Tevatron Collider written by and published by . This book was released on 2011 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transverse beam diffusion rate vs. particle oscillation amplitude was measured in the Tevatron using collimator scans. All collimator jaws except one were retracted. As the jaw of interest was moved in small steps, the local shower rates were recorded as a function of time. By using a diffusion model, the time evolution of losses could be related to the diffusion rate at the collimator position. Preliminary results of these measurements are presented.
Download or read book Measurement of the Effect of Collisions on Transverse Beam Halo Dynamics in the Tevatron and in the LHC written by and published by . This book was released on 2013 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book BEAM DIFFUSION MEASUREMENTS AT RHIC written by R. P. FLILLER (IIIDREES, A.GASSNER, D.MCINTY.) and published by . This book was released on 2003 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: During a store, particles from the beam core continually diffuse outwards into the halo through a variety of mechanisms. Understanding the diffusion rate as a function of particle amplitude can help discover which processes are important to halo growth. A collimator can be used to measure the amplitude growth rate as a function of the particle amplitude. In this paper we present results of diffusion measurements performed at the Relativistic Heavy Ion Collider (RHIC) with fully stripped gold ions, deuterons, and protons. We compare these results with measurements from previous years, and simulations, and discuss any factors that relate to beam growth in RHIC.
Download or read book The Large Hadron Collider written by Lyndon R. Evans and published by EPFL Press. This book was released on 2009-01-01 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the technology and engineering of the Large Hadron collider (LHC), one of the greatest scientific marvels of this young 21st century. This book traces the feat of its construction, written by the head scientists involved, placed into the context of the scientific goals and principles.
Download or read book Numerical Simulations of Transverse Beam Diffusion Enhancement by the Use of Electron Lens in the Tevatron Collider written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Transverse beam diffusion for the Tevatron machine has been calculated using the Lifetrac code. The following effects were included: random noise (representing residual gas scattering, voltage noise in the accelerating cavities) lattice nonlinearities and beam-beam interactions. The time evolution of particle distributions with different initial amplitudes in Hamiltonian action has been simulated for 6 million turns, corresponding to a time of about 2 minutes. For each particle distribution, several cases have been considered: a single beam in storage ring mode, the collider case and the effects of a hollow electron beam collimator. The diffusion coefficient for some representative points in the amplitude space has been calculated by fitting the time evolution of delta-like particle distributions using the diffusion equation, for different machine conditions. The results confirm a strong efficiency of the electron lens as an halo diffusive enhancer, leading to diffusion coefficients which are at least a factor 10K higher than the values obtained for the collision case. This result is confirmed by the Frequency Map Analysis, which shows a clear intensification of resonance lines for particle amplitudes larger than the electron lens inner radius. If compared with past experiments, the simulations successfully reproduce the diffusion coefficients for the beam core, but still present a large discrepancy for halo particles, still under investigation.
Download or read book Channeling and Volume Reflection Based Crystal Collimation of Tevatron Circulating Beam Halo T 980 written by and published by . This book was released on 2010 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: The T980 crystal collimation experiment is underway at the Tevatron to determine if this technique could increase 980 GeV beam-halo collimation efficiency at high-energy hadron colliders such as the Tevatron and the LHC. T980 also studies various crystal types and parameters. The setup has been substantially enhanced during the Summer 2009 shutdown by installing a new O-shaped crystal in the horizontal goniometer, as well as adding a vertical goniometer with two alternating crystals (O-shaped and multi-strip) and additional beam diagnostics. First measurements with the new system are quite encouraging, with channeled and volume-reflected beams observed on the secondary collimators as predicted. Investigation of crystal collimation efficiencies with crystals in volume reflection and channeling modes are described in comparison with an amorphous primary collimator. Results on the system performance are presented for the end-of-store studies and for entire collider stores. The first investigation of colliding beam collimation simultaneously using crystals in both the vertical and horizontal plane has been made in the regime with horizontally channeled and vertically volume-reflected beams. Planning is underway for significant hardware improvements during the FY10 summer shutdown and for dedicated studies during the final year of Tevatron operation and also for a 'post-collider beam physics running' period.
Download or read book Beam Diffusion Measurements Using Collimator Scans in the LHC written by and published by . This book was released on 2013 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conceptual Design of Hollow Electron Lenses for Beam Halo Control in the Large Hadron Collider written by and published by . This book was released on 2014 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collimation with hollow electron beams is a technique for halo control in high-power hadron beams. It is based on an electron beam (possibly pulsed or modulated in intensity) guided by strong axial magnetic fields which overlaps with the circulating beam in a short section of the ring. The concept was tested experimentally at the Fermilab Tevatron collider using a hollow electron gun installed in one of the Tevatron electron lenses. We are proposing a conceptual design for applying this technique to the Large Hadron Collider at CERN. A prototype hollow electron gun for the LHC was built and tested. The expected performance of the hollow electron beam collimator was based on Tevatron experiments and on numerical tracking simulations. Halo removal rates and enhancements of halo diffusivity were estimated as a function of beam and lattice parameters. Proton beam core lifetimes and emittance growth rates were checked to ensure that undesired effects were suppressed. Hardware specifications were based on the Tevatron devices and on preliminary engineering integration studies in the LHC machine. Required resources and a possible timeline were also outlined, together with a brief discussion of alternative halo-removal schemes and of other possible uses of electron lenses to improve the performance of the LHC.
Download or read book Understanding the Large Hadron Collider written by Fred Bortz and published by Cavendish Square Publishing, LLC. This book was released on 2015-07-15 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discover the engineering and science behind particle accelerators, the massive machines that smash the smallest atoms together to observe how they work.
Download or read book Hadron Colliders At The Highest Energy And Luminosity Proceedings Of The 34th Wrshp Of The Infn Project written by Alessandro G Ruggiero and published by World Scientific. This book was released on 1998-02-24 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: The quest for the revelation of the deepest composition of the structure of matter and the nature of the fundamental forces that bind them together is underway, using experiments with colliding hadron beams at the largest energy and luminosity that present and near-future accelerator technology can allow. This book gives the physics motivation of such a collider and discusses the benefits and requirements of the experimental program. Obviously the size of the collider is a major concern, and that is determined by the bending field which is possible to achieve in superconducting magnets; the book includes a discussion on the ultimate expected magnetic field that can be reached. There are also presentations of straw-man designs; in particular, the effects of the synchrotron radiation, which are quite significant at very large energies and large bending fields, are examined, with the possibility of taking advantage of them for the attainment of small beam size and thus luminosity. In addition, detector issues are discussed, especially in relation to the large expected background, the total number of events, and the difficulties of gathering and selecting relevant events. Finally, there is a discussion on the social and political implications of such a project.
Download or read book Large Hadron Collider The written by Bonnie Juettner Fernandes and published by Norwood House Press. This book was released on 2013-07-01 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: What really happened during the Big Bang? Why did matter form? Why do particles have mass? To answer these questions, scientists and engineers have worked together to build the largest and most powerful particle accelerator in the world: the Large Hadron Collider. Correlates with STEM and Physics instruction. Includes glossary, websites, and bibliography for further reading.
Download or read book A Novel Method and Error Analysis for Beam Optics Measurements and Corrections at the Large Hadron Collider written by Andy Sven Langner and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diffusion Due to Beam beam Resonances in Hadron Colliders written by Y. Alexahin and published by . This book was released on 2005 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Beam-beam tune spread in hadron colliders usually is small enough to avoid most dangerous low-order betatron resonances. However, even weak high-order resonances can be detrimental due to cooperative effect of the external noise. Mechanisms of such cooperation are considered, simple analytical estimates of the diffusion rate being verified with numerical simulations. The developed theory is used to evaluate the beam-beam resonance contribution to the emittance growth in the Tevatron.
Download or read book Measurements of the Longitudinal and Transverse Beam Loss at the Tevatron written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the transverse and longitudinal beam losses during a Tevatron store will be presented. The measurements utilize scintillation counters to monitor the nuclear interactions of the 1 TeV halo particles with a scraper that is located near the beam. If the particles are in time with the primary bunches, they are assumed to come from transverse perturbations inducing large betatron oscillations. Particles lost longitudinally drift around the ring due to synchrotron radiation and become asynchronous with respect to the bunches. A pulsed electron lens is then used to induce large betatron oscillations that extract these particles onto the scraper. The resulting nuclear interactions in the scraper are recorded by a gated scintillating counter system. The counting rates from the two channels provide an online measurement of the two types of beam loss. Known beam loss due to interactions at the IP and to nuclear collisions in the residual gas can be subtracted which then exposes the underlying losses from longitudinal and transverse instabilities.
Download or read book Los Alamos Beam Halo Experiment written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We compare macroparticle simulations with measurements from a proton beam-halo experiment in a 52-quadrupole periodic-focusing channel. Three different initial distributions with the same Courant-Snyder parameters and emittances, but different shapes, predict different beam profiles in the transport system. Input distributions with greater population in the tails produce larger rates of emittance growth, a result that is qualitatively consistent with the particle-core model of halo formation in mismatched beams. The simulations underestimate the growth rate of halo and emittance for mismatched beams. Better agreement between simulations and experiment may require an input distribution that represents more accurately the tails of the real input beam.
