High precision modeling of space-charge effects, together with accurate treatment of single-particle dynamics, is essential for designing future accelerators as well as optimizing the performance of ...existing machines. We describe Synergia, a high-fidelity parallel beam dynamics simulation package with fully three-dimensional space-charge capabilities and a higher order optics implementation. We describe the computational techniques, the advanced human interface, and the parallel performance obtained using large numbers of macroparticles. We also perform code benchmarks comparing to semi-analytic results and other codes. Finally, we present initial results on particle tune spread, beam halo creation, and emittance growth in the Fermilab Booster accelerator.
Historically high energy physics computing has been performed on large purpose-built computing systems. In the beginning there were single site computing facilities, which evolved into the Worldwide ...LHC Computing Grid (WLCG) used today. The vast majority of the WLCG resources are used for LHC computing and the resources are scheduled to be continuously used throughout the year. In the last several years there has been an explosion in capacity and capability of commercial and academic computing clouds. Cloud resources are highly virtualized and intended to be able to be flexibly deployed for a variety of computing tasks. There is a growing interest amongst the cloud providers to demonstrate the capability to perform large scale scientific computing. In this presentation we will discuss results from the CMS experiment using the Fermilab HEPCloud Facility, which utilized both local Fermilab resources and Amazon Web Services (AWS). The goal was to work with AWS through a matching grant to demonstrate a sustained scale approximately equal to half of the worldwide processing resources available to CMS. We will discuss the planning and technical challenges involved in organizing the most IO intensive CMS workflows on a large-scale set of virtualized resource provisioned by the Fermilab HEPCloud. We will describe the data handling and data management challenges. Also, we will discuss the economic issues and cost and operational efficiency comparison to our dedicated resources. At the end we will consider the changes in the working model of HEP computing in a domain with the availability of large scale resources scheduled at peak times.
We present validation and results from a simulation of the Fermilab Tevatron including multiple beam dynamics effects. The essential features of the simulation include a fully 3D strong-strong ...beam-beam particle-in-cell Poisson solver, interactions among multiple bunches and both head-on and long-range beam-beam collisions, coupled linear optics, and helical trajectory consistent with beam-orbit measurements, chromaticity, and resistive wall impedance. We validate individual physical processes against measured data where possible, and analytic calculations elsewhere. Finally, we present simulations of the effects of increasing beam intensity with single and multiple bunches, and study the combined effect of long-range beam-beam interactions and transverse impedance. The results of the simulations were successfully used in Tevatron operations to support a change of chromaticity during the transition to collider mode optics, leading to a factor of 2 decrease in proton losses, and thus improved reliability of collider operations.
The booster ionization profile monitor (IPM) obtains transverse beam profiles by measuring the distribution of ions resulting from interaction of the proton beam with background gas in the beam ...chamber. The challenge of the IPM operation is that the measured ion distribution is not an exact representation of the beam distribution, since the ion trajectories are influenced by the electromagnetic field of the beam. We have developed a new model for the dependence of the IPM measurement on the beam parameters, assuming a Gaussian beam distribution. Our model of the ion dynamics in the detector was constrained by making independent measurements of the horizontal beamwidth at injection and extraction and comparing these to data taken from the IPM at the same time. Our calibration results in the formula σ_{measured}=σ_{real}+C_{1}Nσ_{real}^{p_{1}}, where N is the number of protons in the machine, in units of 10^{12}, C_{1}=(1.13±0.06)×10^{-5}, in units of (meters)^{1-p_{1}}/10^{12}, and p_{1}=-0.615±0.013; the subscript “measured” indicates the raw IPM measurement, the subscript “real” the true beamwidth. This result is the first detailed calibration of the response of the booster IPM based on experimental data.
Current state-of-the-art beam dynamics simulations include multiple physical effects and multiple physical length and/or time scales. We present recent developments in Synergia2, an accelerator ...modeling framework designed for multi-physics, multi-scale simulations. We summarize recent several recent results in multi-physics beam dynamics, including simulations of three Fermilab accelerators: the Tevatron, the Main Injector and the Debuncher.
We report on the first measurement of flux-integrated single differential cross sections for charged-current (CC) muon neutrino ($\nu_{\mu}$) scattering on argon with a muon and a proton in the final ...state, 40Ar $(\nu_{\mu},μp)X$. The measurement was carried out using the Booster Neutrino Beam at Fermi National Accelerator Laboratory and the MicroBooNE liquid argon time projection chamber detector with an exposure of 4.59 × 1019 protons on target. Events are selected to enhance the contribution of CC quasielastic (CCQE) interactions. The data are reported in terms of a total cross section as well as single differential cross sections in final state muon and proton kinematics. We measure the integrated per-nucleus CCQE-like cross section (i.e., for interactions leading to a muon, one proton, and no pions above detection threshold) of (4.93 ± 0.76stat ± 1.29sys)×10-38 cm2, in good agreement with theoretical calculations. The single differential cross sections are also in overall good agreement with theoretical predictions, except at very forward muon scattering angles that correspond to low-momentum-transfer events.
Modern beam dynamics simulations require nontrivial implementations of multiple physics models. We discuss how component framework design in combination with the Common Component Architecture's ...component model and implementation eases the process of incorporation of existing state-of-the-art models with newly-developed models. We discuss current developments in componentized beam dynamics software, emphasizing design issues and distribution issues.
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